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12th International Conference on Colloid and Surface Chemistry May 16 – 18, 2016 “Petru Poni” Institute of Macromolecular Chemistry Iasi, Romania

BOOK OF ABSTRACTS

CONTENTS ORGANIZERS ................................................................................................................................................. 2

PREFACE ....................................................................................................................................................... 3 CONFERENCE TOPICS ................................................................................................................................... 4 SCIENTIFIC COMMITTEE............................................................................................................................... 5 ORGANIZING COMMITTEE ............................................................................................................................ 6 SCIENTIFIC PROGRAM .................................................................................................................................. 7 PLENARY LECTURES ..................................................................................................................................... 9 KEYNOTE LECTURES ................................................................................................................................. 23 ORAL COMMUNICATIONS .......................................................................................................................... 27 POSTER PRESENTATIONS ......................................................................................................................... 51 SPONSORS.................................................................................................................................................. 75 AUTHOR’S INDEX ...................................................................................................................................... 86

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016

ORGANIZERS

“Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania

“Ilie Murgulescu” Institute of Physical Chemistry, Bucharest, Romania

Romanian Chemical Society

SupraChem Lab – Laboratory of Supramolecular Chemistry for Adaptive Delivery Systems ERA Chair initiative Horizon 2020 WIDESPREAD 2-2014: ERA Chairs Project no 667387

Book of abstracts

PREFACE The Conference on Colloid and Surface Chemistry started 33 years ago in Bucharest. During the years, the conference was hosted by Cluj-Napoca, Timisoara and Galați. In 2013, the conference was hosted for the first time by „Petru Poni” Institute of Macromolecular Chemistry, Iasi, an institute of excellence of the Romanian Academy. This year, the 12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 is organized once again by „Petru Poni” Institute of Macromolecular Chemistry, in the period 16-18 May. The conference offers the opportunity to present the newest scientific achievements, encouraging a productive exchange of ideas and opinions. Active participation from academy and industry is encouraged. We hope that the conference will be the starting point for new and fruitful collaborations. Waiting to welcome for the conference and, perhaps, a few days before or after it, Bogdan C. SIMIONESCU Dan Florin ANGHEL Co-presidents of ICCSC’2016

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016

CONFERENCE TOPICS 1. Colloid and interface phenomena 2. Organic-inorganic hybrid materials 3. Sol-gel materials 4. Functionally modified surfaces 5. Micro- and nanostructured materials 6. Biomaterials and bioinspired materials 7. Green and environmental chemistry

Book of abstracts

SCIENTIFIC COMMITTEE Acad. Bogdan C. SIMIONESCU, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, and “Gheorghe Asachi” Technical University of Iasi, Romania Acad. Maria ZAHARESCU, “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania Dr. Georgeta POPESCU, founding member of the conference, Research Center for Macromolecular and Membrane Materials, Bucuresti Dr. Dan-Florin ANGHEL “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania Prof. Teresa BASINSKA, Center of Molecular and Macromolecular Studies, Polish Academy of Sciences, Łódź, Poland Dr. Oana CARP, “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania Dr. Dan DONESCU, The National Institute for Research & Development in Chemistry and Petrochemistry, Bucharest, Romania Dr. Ecaterina Stela DRĂGAN, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Valeria HARABAGIU, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Prof. Bjorn LINDMAN, Center of Chemistry and Chemical Engineering, Lund University, Lund, Sweden Prof. Constanța IBĂNESCU, “Gheorghe Asachi” Technical University of Iasi, Romania Dr. Luminita MARIN, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Prof. Maria MIGUEL, Department of Chemistry, Coimbra University, Coimbra, Portugal Dr. Marcela MIHAI, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Mariana PINTEALĂ, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Stergios PISPAS, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens, Greece Dr. Vlad Tudor POPA, “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania Prof. Stanislaw SLOMKOWSKI, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Łódź, Poland

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016

ORGANIZING COMMITTEE Program Chair Dr. Marcela MIHAI, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania

Members Dr. Adriana BARAN, “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania Dr. Ana Irina COCÂRŢĂ, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Florica DOROFTEI, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Claudiu Augustin GHIORGHIŢĂ, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Narcisa MARANGOCI, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Monica MAXIM, “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania Dr. Radu Dan RUSU, “Petru Poni” Institute of Macromolecular Chemistry, Iasi, Romania Dr. Gabriela STÎNGĂ, “Ilie Murgulescu“ Institute of Physical Chemistry, Bucharest, Romania

Book of abstracts

SCIENTIFIC PROGRAM Monday, May 16 800 – 915 0915 – 0930

Registration of Participants Conference Opening Session 1. CONFERENCES Conference hall Chair: Bogdan C. SIMIONESCU, Dan-Florin ANGHEL 0930 – 1010 PL1. Björn LINDMAN, Lund University, Sweden 1010 – 1050 PL2. Maria ZAHARESCU, IMIPC, Bucharest, Romania 1050 – 1110 Coffee Break Session 2. CONFERENCES Conference hall Chair: Maria ZAHARESCU, Stanislaw SLOMKOWSKI 1110 – 1150 PL3. Simona SCHWARZ, IPF, Dresden, Germany 1150 – 1230 PL4. Stergios PISPAS, TPCI, Athens, Greece 1230 – 1330 ICMPP visit 1330 – 1500 Lunch Session 3. CONFERENCES Conference hall Chair: Svetlana BRATSKAYA, Valeria HARABAGIU 1500 – 1540 PL5. Elena MILEVA, IPC, Sofia, Bulgaria 1540 – 1605 KN1. Maria VISA, University of Brasov, Romania 1605 – 1625 Coffee Break Sessions 4/5. ORAL COMMUNICATIONS Conference hall Library hall Chair: Anca DUȚĂ, Adriana BARAN Chair: Diana CIOLACU, Alina IOVESCU 1625 – 1640 OC1. Geta DAVID, UTI OC2. Ioana Cătălina GÎFU, IMIPC 1640 – 1655 OC3. Daniel G. ANGELESCU, IMIPC OC4. Irina POPESCU, PPIMC 1655 – 1710 OC5. Monika GOSECKA, CMMS, OC6. Ludmila ARICOV, IMIPC 1710 – 1725 OC7. Maria COVEI, Univ. Brasov OC8. Andra HUMELNICU, PPIMC 25 40 17 – 17 OC9. Elena Livia SIMION, IMIPC OC10. Anca Ruxandra LEONTIES, IMIPC 1740 – 1755 OC11. Gabriela CÂRJĂ, UTI OC12. Ana Irina COCARȚĂ, PPIMC 55 15 17 – 18 Coffee Break Session 6. CONFERENCES Conference hall Chair: Piero BAGLIONI 1815 – 1855 PL6. Mariana PINTEALA, PPIMC, Iasi, Romania Session 7. POSTERS Conference hall Chair: Florica DOROFTEI, Claudiu GHIORGHIȚĂ, Anca LEONTIES, Gabriela STÎNGĂ 55 18 – 1930 P1 – P23 Posters will be posted on the panels after participants’ registration and will remain exhibited during the entire conference period.

1930 – 2200

Dinner – Vanatorul Restaurant

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016

Tuesday, May 17

0900 – 940 0940 – 1020 1020 – 1040

1040 – 1120 1120 – 1200 1200 – 1220

1220 – 1300 1300 – 1325 1325 – 1500

1500 – 1540 1540 – 1605 1605 – 1625

1625 – 1640 1640 – 1655 1655 – 1710 1710 – 1725 1725 – 1740 1740 – 1800

1800 – 1840 1840 – 1900 1930 – 2200

Session 8. CONFERENCES Conference hall Chair: Simona SCHWARZ, Stergios PISPAS PL7. Maria MIGUEL, Coimbra University, Portugal PL8. Piero BAGLIONI, University of Florence, Italy Coffee Break Session 9. CONFERENCES Conference hall Chair: Mariana PINTEALA, Björn LINDMAN PL9. Svetlana BRATSKAYA, YPIOS, Vladivostok, Russia PL10. Dan-Florin ANGHEL, IMIPC, Bucharest, Romania Coffee Break Session 10. CONFERENCES Conference hall Chair: Teresa BASINSKA, Monika GOSECKA PL11. Stanislaw SLOMKOWSKI, CMMS, Lodz, Poland KN2. Anca DUTA, University of Brasov, Romania Lunch Session 11. CONFERENCES Conference hall Chair: Maria MIGUEL, Geta DAVID PL12. Teresa BASINSKA, CMMS, Lodz, Poland KN3. Marcela MIHAI, PPIMC, Iasi, Romania Coffee Break Sessions 12/13. ORAL COMMUNICATIONS Conference hall Library hall Chair: Maria VISA, Marcela MIHAI Chair: Irina POPESCU, Daniel ANGELESCU OC13. Gabriela STÎNGĂ, IMIPC OC14. Diana CIOLACU, PPIMC OC15. Claudiu GHIORGHIȚĂ, PPIMC OC16. Alina IOVESCU, IMIPC OC17. Monica MAXIM, IMIPC OC18. Anca PETROVICI, PPIMC OC19. Diana Felicia LOGHIN, PPIMC OC20. Adriana BĂRAN, IMIPC OC21. Marieta BALCAN, IMIPC OC22. Anca-Dana BENDREA, PPIMC Coffee Break Session 14. CONFERENCES Conference hall Chair: Elena MILEVA PL13. Valeria HARABAGIU, PPIMC, Iasi, Romania Conference Closing Conference Dinner – Majestic Restaurant

Wednesday, May 18 1000 – 1100 1100 – 1800

Visit of the Palace of Culture Excursion Ruginoasa (Cuza Castle) – Hanul Ancutei – Miclauseni (Sturdza Castle)

Book of abstracts

PLENARY LECTURES

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 1. COMPETING FORCES IN CELLULOSE DISSOLUTION Björn Lindman*, Luís Alves, Maria Miguel, Bruno Medronho Center of Chemistry and Chemical Engineering, Lund University, Sweden Department of Chemistry, Coimbra University, Portugal *E-mail: [email protected]

Cellulose is difficult to dissolve and the use of cellulose in formulations, including the formation of colloidal particles and fibers is limited by solubility limitations. Cellulose is known to be insoluble in water and in many organic solvents, but can be dissolved in a number of solvents of intermediate properties, like N-methylmorpholine N-oxide (NMMO) and ionic liquids (ILs) which, apparently, are not clearly related. It can also be dissolved in water at extreme pHs, in particular if a cosolute of intermediate polarity is added. The insolubility in water is often referred to strong intermolecular hydrogen bonding between cellulose molecules. Revisiting some fundamental polymer physicochemical aspects (i.e. intermolecular interactions) a different picture is now revealed: cellulose is significantly amphiphilic and hydrophobic interactions are important to understand its solubility pattern [1]. In this work we try to expose the root of developing novel solvents for cellulose based on a critical analysis of the intermolecular interactions involved and mechanisms of dissolution. The hypothesis of cellulose insolubility induced by hydrophobic interactions has created significant interest. We also illustrate the association and precipitation of cellulose from rheology studies and how it can be affected by other amphiphilic compounds. Cellulose has a strong tendency to re-assemble when dissolved; this process is strongly affected by surfactants and other additives affecting hydrophobic interactions. References [1] B. Medronho, B. Lindman, Curr. Opin. Colloid Interface Sci. 2014, 19, 32-40.

Book of abstracts PL 2. SOL-GEL CHEMSITRY. BASIC RESEARCHES AND APPLICATIONS Maria Zaharescu* ”Ilie Murgulescu” Institute of Physical Chemistry of the Romanian Academy, 202, Splaiul Independentei, 60021, Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Among the non-conventional wet chemical processes of obtaining oxide nanostructures, the sol-gel method is one of the mostly used and studied as well. As it is well known, the sol-gel process represents the formation of an inorganic polymeric network by reactions in the solution at low temperatures. In the second step the inorganic amorphous polymers could be converted by adequate thermal treatments into glasses at temperatures far lower than the melting temperature of the corresponding oxides or in crystalline materials [1]. The most important step of the method is represented by the formation of the amorphous inorganic polymers in solution that allows properties tailoring of the resulted products [2]. However, this first step is the most difficult to be investigated, due to the high number of reactions that take place simultaneously leading to formation of a high number of molecular species. In the presentation some information on the chemistry of the sol-gel processes, especially in the silica based systems, will be given based on gas chromatography coupled with mass spectrometry (GCMS) [3, 4]. The influence of microwaves (MW) on the sol-gel process in doped and undoped TiO2 systems will be also discussed based on high pressure liquid chromatography (HPLC) investigations [5]. Preparation and complex characterization of oxide and hybrid nanostructures as films [6], powders (including 1D nanostructures) [6], nanocomposites and some of their possible applications will be also presented.

Figure 1. Sol-gel SiO2 powders [6]

Figure 2. Sol-gel SiO2 nano/ micro tubes [6]

Figure 3. Sol-Gel V-doped TiO2 films obtained in the presence of MW [5]

References [1] H. Schmidt, J. Non-Cryst. Solids 1988, 100, 51-64. [2] S. Sakka, K. Kamya, J. Non-Cryst. Solids 1982, 42, 31-46. [3] A. Jitianu, A. Britchi, C. Deleanu, V. Badescu, M. Zaharescu, J. Non-Cryst. Solids 2003, 319, 263-279. [4] A. Jitianu, M. Gartner, M. Zaharescu, D. Cristea, E. Manea. Mat. Sci. Eng. 2003, C23, 301-305. [5] L. Predoana, I. Stanciu, M. Anastasescu, J. M. Calderon-Moreno, M. Stoica, S. Preda, M. Gartner, M. Zaharescu, J. Sol-Gel Sci. Technol. 2016, DOI 10.1007/s10971-016-3972-9. [6] C. Anastasescu, M. Anastasescu, V.S. Teodorescu, M. Gartner, M. Zaharescu, J. Non-Cryst. Solids, 2010, 356, 2634-2640.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 3. INVESTIGATION OF THE ADSORPTION PROCESS OF HEAVY METAL IONS FROM AQUEOUS SOLUTIONS ON CHITOSAN Simona Schwarz*, Mandy Mende Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany *E-mail: [email protected]

Pollution by heavy metals is a serious threat for the environment, aquatic ecosystem, and human health. Hence, heavy metals are nonbiodegradable and potentially toxic at very low concentrations. Chitosan is a good adsorbent for heavy metal ions in solution. We have used chitosan flakes, powder and beads with a degree of deacetylation of 90 % as adsorbent. First the dependence of the adsorption capacity on the adsorption time and the initial metal salt concentration was investigated. With increasing adsorption time as well as the initial metal salt concentration the adsorption capacity increases. Sulfate was the anion for all three salts investigated. Highest adsorption capacity was achieved for copper(II)ions on chitosan powder with 150 mg/L. Iron(II)- and nickel(II)ions adsorbed with an adsorption capacity of 80 mg/L. By SEM analysis the formation of crystal-like structures was observed at higher adsorption time and higher initial salt concentration, when copper(II)sulfate and iron(II)sulfate were used. The adsorption of the nickel salt resulted in a smoother layer on the chitosan surface. SEM-EDX analysis revealed that sulfate adsorbs on chitosan surface besides the metal cations used. In the case of copper and nickel sulfate all elements (i.e. copper, nickel, and sulfur) are uniformly distributed over the whole chitosan surface. This fact gives evidence that both cation as well as anion of the used salts adsorbed on chitosan surface. The distribution of the element iron on chitosan surface is not uniformly over the whole chitosan surface due to the rapid oxidation of the iron(II)ions on air resulting in partially adsorbed iron oxide. Sulfur was uniformly distributed on chitosan surface too. However, iron was only detected at certain areas on chitosan. The simultaneous adsorption of salt cations and anions used can be interpreted due to the investigated pH range between 5 and 6 in which the adsorption experiments were carried out. The coexistence of protonated and unprotonated amine groups allows that salt cations form chelate complexes with unprotonated amine groups and salt anions adsorb on chitosan surface by electrostatic interaction. 5 g/L CuSO4

5 g/L FeSO4

3 g/L NiSO4

Figure 1. SEM images (5k x magnification) of chitosan surface pure and after heavy metal ion adsorption Acknowledgements This work was supported by the Central Innovation Programme (ZIM) of the Federal Ministry of Economy and Energy (BMWi) (KF 2022812RH1). The authors thank Heppe Biolog GmbH from Germany for the support of the materials and discussion and cooperativeness. References [1] M. Mende, D. Schwarz, S. Schwarz, proceedings of the word congress on civil, structural, and environmental engineering, accepted, in press. [2] Mandy Mende, Dana Schwarz, Christine Steinbach, Regine Boldt, Simona Schwarz, Colloids and Surfaces A: Physicochemical and Engineering Aspects, submitted

Book of abstracts PL 4. FUNCTIONAL NANOSTRUCTURES FROM AMPHIPHILIC BLOCK COPOLYMERS AND OTHER BUILDING BLOCKS Stergios Pispas* Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., 11635 Athens Greece Institute/Company, Street, Postal Code City, Country *E-mail: [email protected]

Amphiphilic block copolymers have the ability to self-organize in a variety of nanometer scale structures, usually as a response to changes in external physicochemical stimuli, as well as to interact with a variety of other building blocks, toward the formation of hybrid and functional nanostructures. These distinctive abilities allow the utilization of amphiphilic block polyelectrolytes, in particular, in a number of practical applications. In this presentation we will discuss our resent results on the design and synthesis of novel amphiphilic block copolymers and block polyelectrolytes, their self-assembly in aqueous solutions and surfaces, and their interaction with proteins, nucleic acids, low molecular weight surfactants and inorganic nanoparticles, producing colloidal and surface nanostructures of different morphologies and functionalities [1-4]. The ultimate goal is to understand and master ways for controlling self-assembly of macromolecular materials and the creation of functional nanostructures able to find use in applications related to drug and gene delivery, enzymatic catalysis, biomimetics and biotechnology, and thin film designs. References [1] M. Uchman, S. Pispas, L. Kovacik, M. Stepanek, Macromolecules 2014, 47, 7081-7090. [2] E. Haladjova, S. Rangelov, Ch. B. Tsvetanov, V. Posheva, E. Peycheva, V. Maximova, D. Momekova, G. Mountrichas, S. Pispas, A. Bakandritsos, Langmuir 2014, 30, 8193-8200. [3] N. Pippa, M. Karayianni, S. Pispas, C. Demetzos, Int. J. Pharm. 2015, 401, 136-143. [4] A. Papagiannopoulos, A. Christoulaki, N. Spiliopoulos, A. Vradis, C. Toprakcioglu, S. Pispas, Langmuir 2015, 31, 685-694.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 5. SMART COMPLEX FLUIDS BASED ON ANTENNARY OLIGOGLYCINES Elena Mileva*, Anna Gyurova, Stefan Stoyanov, Dimi Arabadzhieva, Ljubomir Nikolov Institute of Physical Chemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria *E-mail: [email protected]

Aqueous systems based on synthetic antennary oligoglycines have high potential for biomedical and water-purity-control applications. The oligoglycine molecules self-organize into supramolecular assemblies (tectomers) in aqueous media, forming bulk hydrophilic nanoplatforms, vesicles, etc. The innate reason for the self-organization is the onset of highly cooperative arrangement of intra- and intermolecular hydrogen bonds. The properties of these smart complex fluids may be finely tuned by changes of pH and/or the addition of charged entities (low molecular mass electrolytes, or high molecular mass substances). A combined procedure is developed, including the registration of inception and stability of the bulk aggregates of various sizes and charges, examination of the properties of the interfacial layers at the solution/air boundary and the drainage characteristics of microscopic foam films. Due to the specific structure and properties of the obtained tectomers, these complex fluid systems may be applied for the entrapment of charged nanospecies of various origin. Thus the obtained results suggest that the selfassembled nanostructures of antennary olygoglycines may be implemented e.g. as indicators and captive agents for trace quantities of dangerous substances of biological origin (endotoxins) in aqueous media [1]. Acknowledgements The investigation is performed under the umbrella of COST Action MP 1106 “Smart and green interfaces from single bubbles and drops to industrial, environmental and biomedical applications”. S.S. is grateful to the World Federation of Scientists for a PhD Scholarship. References [1] A. Gyurova, S. Stoyanov, E. Mileva, Colloids and Surfaces A 2014, 460, 130-136.

Book of abstracts PL 6. NON-VIRAL DELIVERY SYSTEMS FOR GENE THERAPY Mariana Pinteala*, Bogdan C. Simionescu ”Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Polycationic compounds, especially those based on hyperbranched poly(ethylene imine) (PEI), have been extensively studied as gene transfer vehicles due to their outstanding capacity to condense nucleic acid molecules via electrostatic interaction and due to their “proton sponge effect” that allows polyplexes to be released in the cytosol form. The present study focuses on the synthesis of different non-viral vectors, using low molecular mass PEI (2 kDa) connected to a core molecule. Due to their high biocompatibility, fullerene C60, tetramethylcyclotetrasiloxane (cD4H) and β-cyclodextrine (β-CD) were selected as core molecules. Transfection was monitored on HEK cell line by using an EYFP plasmid encoding a green fluorescent protein. Figure 1. Schematic representation of nanovector complexation with plasmid DNA. The corresponding nanovectors – C60-PEI, C60-PEG-PEI, cD4H-AGEPEI and β-CD-PEG-PEI were investigated as concerns plasmidial DNA (pDNA) packaging by DLS, zeta potential measurements, TEM / AFM for size and morphology determination and gel retardation assay to assess the packing capacity of the vectors at different N/P ratios (the ratio between nitrogen from PEI and phosphorus from DNA). Biological tests on HEK 293 cell culture were performed to quantify the transfection yield, both as transfected cell percentage and protein express (EYFP) percentage, and to evaluate cell viability after treating with polyplex solutions. The highest transfection yields were recorded for cD4H-AGE-PEI/pEYFP at N/P=200 (~36%). The PEGylated compounds C60-PEG-PEI and β-CD-PEG-PEI exhibit a lower percent of transfected cells, of 10% and 14%, respectively (for N/P ratios between 100÷200), but show an average fluorescence intensity (MFI) similar to that of the commercial transfection agent (Superfect®, Qiagen) used as positive control. All investigated compounds display a good cytocompatibility, the PEGylated ones additionally inducing a significant cell proliferation, even at higher N/P ratios. Acknowledgements This work was supported by the Romanian National Authority for Scientific Research grant, CNCS – UEFISCDI, project number PN-II-ID-PCCE-2011-2-0028 and the H2020 ERA Chairs Project – SupraChem Lab Laboratory of Supramolecular Chemistry for Adaptive Delivery Systems ERA Chair initiative (contract no: 667387).

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 7. DNA IS A HIGHLY CHARGED AMPHIPHILIC POLYMER THAT ASSOCIATES STRONGLY WITH CATIONIC SURFACTANTS Maria Miguel*, Björn Lindman, Rita Dias, Carmen Morán, Diana Costa Department of Chemistry, Coimbra University, Coimbra, Portugal *E-mail: [email protected]

As a strongly negatively charged polyelectrolyte, DNA associates strongly with cationic cosolutes, such as surfactants, lipids, polymers and proteins; all these systems are characterized by a strong associative phase separation. Cationic lipids and surfactants are efficient in compacting DNA and can also be efficient transfection agents. An overview of DNA-surfactant interactions is presented illustrating the binding of surfactants to DNA in bulk and consequences in terms of phase behavior and compaction. Phase diagrams show a strong associative phase separation, with two-phase regions increasing strongly in size with the increase of the cationic surfactant chain length. Techniques used for the characterization of DNAsurfactant complexes include small-angle X-ray scattering (SAXS), light scattering, nuclear magnetic resonance (NMR), cryogenic transmission electron microscopy (cryo-TEM), and fluorescence microscopy. Cationic surfactants are very efficient in compacting DNA, thus changing the extended DNA molecules into compact globules. We are also interested in combining surfactants to control compaction and we discuss the de-compaction induced by anionic surfactants and in general the interaction of DNA with mixed cationicanionic systems. A general understanding of the interactions between DNA and oppositely charged agents, and in particular of their phase behaviour, has provided a basis for developing novel DNA-based materials, including gels and gel particles. In particular, we describe the preparation of covalent DNA gels obtained by cross-linking of linear DNA molecules, and describe their swelling-deswelling behavior. It is found that covalent gels offer novel opportunities for monitoring DNA-cosolute interactions. A weak deswelling is obtained with simple 1:1 electrolytes, whereas the deswelling becomes much more important with increasing valency of the counterion. For multivalent counter-ions such as in polyelectrolytes and proteins a strong deswelling is observed for low concentrations. Cationic surfactants give a very strong deswelling but only above the critical micelle concentration (cmc) where highly charged aggregates form. This gel deswelling is reversible as can be learnt from the observation that gels compacted with cationic surfactant reswells to the original volume on adding an anionic surfactant. Recently, also plasmid DNA gels have been prepared and investigated with respect to their swelling and deswelling in aqueous solution containing different additives, such as metal ions, surfactants, polyamines, proteins and drugs. The photodisruption of pDNA gels was used as a strategy to promote controlled pDNA release. Cell viability assays also suggest that the pDNA gels are biocompatible. Based on the associative phase separation and interfacial diffusion, we have also developed a way to prepare DNA gel particles without adding any kind of cross-linker or organic solvent; and the preparation of DNA particles, by just mixing DNA with surfactant, polycation and protein solutions, has been achieved. Surface morphology, the degree of DNA entrapment, the swelling/deswelling behavior and kinetics of DNA/protein release are also described. The stronger interaction of ssDNA, as compared with dsDNA, suggests the important role of the amphiphilicity of DNA on the interactions. These DNA gel particles were also assessed for haemolysis. It is our belief that these findings may increase the potential of these systems as delivery and codelivery systems.

Book of abstracts PL 8. PHYSICAL AND CHEMICAL GELS FOR FINELY CONTROLLED CLEANING OF CULTURAL HERITAGE Piero Baglioni* Department of Chemistry& CSGI, University of Florence, Via della Lastruccia 3 - Sesto Fiorentino, 50019 Florence, Italy *E-mail: [email protected]

Works of art and artifacts that constitute our cultural heritage are subject to deterioration. Their surfaces interacting with the environment are the most prone to aging and decay; accordingly, soiling is a prime factor in the degradation of surfaces, chemical and mechanical degradation are often associated to soiling and lead to the disfigurement of a piece of art. The effects of these processes are usually strongly amplified by the protective coatings (mainly acrylic and vinyl polymers), applied in previous restoration treatments. In the past years we pioneered the synthesis and the application of several advanced systems for the consolidation and the cleaning of works of art, as hydroxides nanoparticles (wall paintings, paper and wood), microemulsions and chemical/physical gels.

Micellar solutions and microemulsions constitute very efficient systems for the removal of acrylic, vinyl and alkyl polymers, dust or grime/soil. These systems (as well as neat solvents used in "traditional" conservation) can be confined into chemical and physical gels having proper nano-domains for the upload or the delivery of compounds from/to the work of art. For example, a fine control of the cleaning procedure can be obtained even for challenging cleanings as water sensitive works of art, where the cleaning can be achieved by using water confined into gels, and leaving no residues on the works of art. Example from the application of these new systems/methods to the cleaning of classic and modern/contemporary art (J. Pollock, Picasso, Castellani, Sironi, pressure sensitive tapes, Arienti, etc.) will be highlighted [1-8]. References 1) P. Baglioni, E. Carretti, D. Chelazzi, Nat. Nanotechnol. 2015, 10, 287-290. 2) P. Baglioni, D. Chelazzi, R. Giorgi, Nanotechnologies in the Conservation of Cultural Heritage - A compendium of materials and techniques, Springer, 2015 3) P. Baglioni, D. Chelazzi, Nanoscience for the Conservation of Works of Art, Royal Society of Chemistry, 2013. 4) M. Baglioni, D. Berti, J. Teixeira, R. Giorgi, P. Baglioni, Langmuir 2012, 28, 15193–15202. 5) M. Baglioni, R. Giorgi, D. Berti, P. Baglioni, Nanoscale 2012, 4, 42–53. 6) M. Baglioni, D. Rengstl, D. Berti, M. Bonini, R. Giorgi, P. Baglioni, Nanoscale 2010, 2, 1723–1732. 7) R. Giorgi, M. Baglioni, D. Berti, P. Baglioni, Acc. Chem. Res. 2010, 43, 695–704. 8) E. Carretti, E. Fratini, D. Berti, L. Dei, P. Baglioni, Angew. Chem. Int. Ed. 2009, 48, 8966−8969.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 9. GREEN SYNTHESIS OF GOLD NANOPARTICLES USING CHITOSAN AND ITS DERIVATIVES Alexander Pestov1,2, Svetlana Bratskaya2* 1I.

Ya. Postovsky Institute of Organic Synthesis, Ural Branch of RAS, 20, S. Kovalevskoy str., Yekaterinburg 620990, Russia 2Institute of Chemistry, Far East Branch of RAS, 159, prosp.100-letiya Vladivostoka, Vladivostok 690022, Russia *E-mail: [email protected]

Biogenic synthesis of metal nanoparticles attracts an increasing interest due to its compliance with the principles of “green” chemistry, non-toxicity, and biocompatibility of fabricated materials. The polycation nature of chitosan is particularly favorable for gold nanoparticles synthesis, since, on the one hand, chitosan effectively binds [AuCl4]– ions, and on the other hand, stabilizes formed nanoparticles due to the high affinity of N-containing functional groups to the surface of metallic gold. In green synthesis of gold plasmon nanoparticles and nanodots, the efficient coordination of precursor ion Au(III) by the polymer at the first stage of the process is extremely important [1]. Moreover, the balance of coordinating and reducing moieties is a crucial factor that determines the size of gold nanoparticles formed in biopolymer solutions without external reductants. Despite numerous reports on chitosan and its derivatives application for Au nanoparticles synthesis, neither the mechanism of Au(III) ions reduction by chitosan nor the chemical structure of the reaction by-products has been investigated in details. The influence of functional fragments in chitosan macromolecule on the morphology of the gold nanoparticles and mechanism of Au(III) reduction also remains unknown. Here we present comprehensive study of Au(III) reduction mechanism by chitosan and the series of its N-derivatives containing N-heterocyclic substituents. The data obtained using UV-vis spectrophotometry, viscosimetry, colloid titration, and 1H and 13C NMR spectroscopy enabled us to propose mechanism of Au(III) reduction by chitosan and its derivatives. Regardless of the type of functionality in substituted chitosan formation of gold nanoparticles starts with complexation of Au(III) and hydrolysis of adjacent glycoside bond. The products of hydrolysis act as main reducing species. Reduction rate and size of the gold nanoparticles strongly depend on polymer-Au(III) complex stability and metal/ligand ratio. Water soluble luminescent gold nanoparticles with average size 2.3 nm were synthesized using N(4-imidazolyl)methylchitosan (IMC) as both reducing and stabilizing agent. Reduction of Au(III) to gold nanoparticles in IMC solution was a slow process, in which coordination power of biopolymer controls both reducing species concentration and gold crystal growth rate. Gold nanoparticles formed in IMC solution do not manifest surface plasmon resonance, but exhibit luminescence at 375 nm under UV light excitation at 230 nm. Due to biological activity of imidazolyl-containing polymers and their ability to bind proteins and drugs, the obtained ultra-small gold nanoparticles can find an application for biomolecules detection, bioimaging, drug delivery, and catalysis. Acknowledgements Financial support from Russian Science Foundation (project № 14-13-00136) is gratefully acknowledged. References [1] B.A. Rozenberg, R. Tenne, Prog. Polym. Sci. 2008, 33, 40–112.

Book of abstracts PL 10. MICROEMULSIONS FROM ENHANCED OIL RECOVERY TO HYBRID ENGINE FUELS: AN OVERVIEW Dan-Florin Anghel*, Marieta Balcan, Monica Elisabeta Maxim, Florentina Cristina Mihailescu Colloid Chemistry Laboratory, ‘Ilie Murgulescu’ Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, Post Office 12, P.O. Box 194, 060021 Bucharest, Romania *E-mail: [email protected]; [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Enhanced oil recovery (EOR) and hybrid engine fuels (HEF) are nowadays topics of high worldwide interest. They are tightly related because have the same source, the crude oil. It is important to stress that human being did a lot of achievements during his evolution, but is still unable to produce crude oil. Crude oil is the most important resource of energy available on earth. It is processed to diesel, petrol and jet fuels for cars, trucks, ships, planes, stationary electrical generators, etc. The increased demand of fuel, the indiscriminate extraction and depletion of crude oil reservoirs entailed shortages in supply and fluctuant prices on market [1, 2]. The interest in EOR comes from the fact that the current primary and secondary extraction technologies take out only one-third of the oil-in-place. The rest remains trapped into the pores of reservoir rock. Therefore, the recovery of this huge amount of crude oil is a major task. To achieve this goal physical and chemical processes have been proposed. The chemical processes that have been applied in the field are the floodings such as: alkaline, polymer, surfactant, polymer/surfactant and microemulsion. Microemulsion (ME) is advantageous because it displaces the crude by lowering the oil/water interfacial tension (σow), to ultra-low values (< 10-3 mN/m), and controls the mobility. As a consequence, ME is able to recover large amounts of crude oil, otherwise unrecoverable. Therefore, a very important topic is design and formulation of optimal microemulsions. On the other hand, the interest in AEF is in turn generated by reservoir depletion and by the damage of environment as well. Since diesel is a major contributor to these issues, many efforts are now done to replace it. A promising alternative towards this end are microemulsions (ME) with neat diesel, diesel-vegetable oil (VO) blends, or with VO. Vegetable oils are similar to diesel, have no sulfur and aromatics, are biodegradable, renewable and eco-friendly. Their main disadvantages are the low volatility and high viscosity. These problems can be overcome by dilution, pyrolysis, and trans-etherification or by ME. ME allow partial or total substitution of diesel with vegetable oil, and bring water in fuel, which is benefic both for engine and environment. This talk is devoted to microemulsions for EOR and HEF. It is focused on preparation by means of phase diagrams. Emphasis is put on handling the phase behavior, oil/water interfacial tension, particle size of the dispersed phase, solubilization of oil and water (SP o and SPw), viscosity, cloud and pour point, which are key parameters in formulating optimal ME. The microemulsions were obtained with various surfactants, surfactant-cosurfactant blends, oils and waters. The results obtained reveal that one-phase ME decreases with the hydrophobicity of surfactant and by salt, but increases for surfactant-cosurfactant mixtures. For a given system, increasing the salt concentration brings about the Winsor (W) sequence: WI ↔ WIII ↔ WII. In the WIII systems, σow is minimal, whereas SPo, SPw and the particle size of MF are maximal. These criteria apply to both EOR and HEF microemulsions. In the first case, the obtained ME were used in two successful field experiments. In the case of HEF microemulsions, additional criteria like viscosity, calorific power, cloud and pour points have to be met. The designed microemulsions have slightly higher viscosities than neat diesel, whereas the calorific power, cloud and pour points are comparable to it. The presentation is a useful approach to design optimal microemulsions for enhanced oil recovery as well as hybrid fuels for diesel engine. Acknowledgements The research for this paper has been carried out within the Functional Complex Colloids Program of the ‘Ilie Murgulescu’ Institute of Physical Chemistry, financed by the Romanian Academy. The authors gratefully acknowledge the support of the EU (ERDF) and Romanian Government allowing for acquisition of research infrastructure under POS-CCE O 2.2.1 project INFRANANOCHEM, No. 19/01.03.2009. This work is also supported by the PN-II-ID-PCE-2011-3-0916 Exploratory Research Project. References [1] US Energy Information Agency. https://www.eia.gov/forecasts/steo/report/prices.cfm. [Accessed: 2016-02-10]. [2] Bloomberg Business, http://www.bloomberg.com/energy [Accessed: 2016-02-10].

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 11. POLYSILOXANE MICROSPHERES AND THEIR CERAMIC DERIVATIVES Stanislaw Slomkowski*, Witold Fortuniak, Julian Chojnowski, Piotr Pospiech, Urszula Mizerska Center of Molecular and Macromolecular Studies, Polish Academy of Sci., Sienkiewicza 112, 90-363 Lodz, Poland *E-mail: [email protected]

Lecture will present a new route to synthesis of all-polysiloxane microspheres and their derivatives with reactive organofunctional groups. The pristine polysiloxane microspheres could be pyrolized yielding the crack-free silicon oxycarbide particles. The all-polysiloxane microspheres containing a large number of silanol groups were obtained by a process including combination of the four competitive/consecutive reactions of polyhydromethylsiloxane (PHMS) catalyzed by a Pt(0) complex in an aqueous emulsion process [1]. These reactions included (i) hydrosilylation of olefinic bond of a cross-linker with the SiH group on the polymer, (ii) hydrolysis, and in some cases alcoholysis, of the SiH bond in the polymer and (iii) dehydrogenative condensation of the SiOH group formed in the hydrolysis with the SiH group. A solution of PHMS with divinyltetramethyldisiloxane (DVTMS) cross-linker together with the catalyst was mechanically emulsified with water. The polymer cross-linking and the silanol formation occurred in the formed emulsion. Usually the preliminary hydrosilylation was carried out before emulsification. In this way the vinylsiloxane was grafted on PHMS. In the emulsion process a large number of SiH groups on PHMS were transformed into SiOH hydrophilic groups. This reaction did occur both, on the surface of microspheres and in their bulk. The cross-linking of PHMS resulted from hydrosilylation of vinyl groups grafted on the polymer and by dehydrogenative condensation of the SiH groups with the silanol groups which are formed on PHMS. The obtained microspheres were modified by reactions with reactive silanes containing organofunctional groups (vinyl, amine and epoxide). The preceramic microspheres, with average diameters from 7.6 to 56 μm, were pyrolyzed at various temperatures. Results of the first studies of this subject were published in our recent paper [2]. In the lecture we will provide results of detailed characterization of the pyrolyzed microspheres and their precursors based on 29Si and 13C MAS NMR, FTIR spectroscopy, and elemental analysis. The structures of the microspheres were examined by SEM. Some samples were also investigated by XRD and Raman spectroscopy. All of the synthesized preceramic microspheres retained their regular spherical shapes during pyrolysis at temperatures of up to 1200 °C. Heating at 1000 °C and 1200 °C yielded amorphous silicon oxycarbide ceramic materials with segregated free carbon domains. The chemical and physical structures of the obtained ceramic microspheres were significantly influenced by the modification of the preceramic materials. The above-described simple method allowed to obtain a library of silicon containing particles, from soft, swellable polysiloxane microspheres with functional groups suitable for immobilization of catalysts, in particular enzymes. Acknowledgements The financial support from NCN grant 2013/11/B/ST5/01615 is highly appreciated. References [1] W. Fortuniak, J. Chojnowski, S. Slomkowski, P. Pospiech, J. Kurjata, Polymer 2013, 54, 3156-3165. [2] W. Fortuniak, J. Chojnowski, S. Slomkowski, A. Nyczyk-Malinowska, P. Pospiech, U. Mizerska, Mater. Chem. Phys. 2015, 155, 83-91.

Book of abstracts PL 12. ASSEMBLIES OF COLLOIDAL HYDROPHILIC PARTICLES CONTAINING POLYGLYCIDOL: PREPARATION, CHARACTERIZATION, APPLICATIONS Teresa Basinska*, Monika Gosecka, Patrycja Komar, Stanislaw Slomkowski Center of Molecular and Macromolecular Studies,Polish Academy of Sciences, H. Sienkiewicza 112, 90-363 Lodz, Poland, *E-mail: [email protected]

Nowadays assemblies of colloidal particles are manufactured on a small or larger scale for research and practical purposes; applications in optical or electronic devices, biosensors, tissue engineering or cells cultures, medical diagnostic tests etc. For the all above-mentioned applications the controlled arrangement of nano- or microparticles is required and the properties of the particles should be tailored for the final material needs. In various biomedical applications of colloidal materials the particles with the hydrophilic shells and reactive groups suitable for binding biomolecules are needed. This is because these particles usually should carry-on immobilized proteins (antigens/antibodies) which acting in body fluids it should be “invisible” for all biomolecules other than the targeted ones. The particles with two kinds of shape as well as and their assemblies were investigated. Namely, the core-shell spherical particles with polystyrene cores and shells containing hydrophilic polyglycidol segments (P(S/PGLy) and particles with similar chemical composition and core-shell structure but with the ellipsoidal shapes. The latter were formed from the spherical ones [1]. The lecture will present results of the studies of relations between chemical structure, hydrophilicity and shape of the particles and morphology of their assemblies on patterned surfaces. Controlled arrangement of attached particles can be achieved in this way [2]. Moreover, we were interested in formation of 3-dimensional assemblies of particles known as colloidal photonic crystals with specific maxima of diffracted visible light (Bragg peaks). The characteristic features of the colloidal crystals composed of the core-shell poly(styrene/polyglycidol) particles will be discussed. Particularly interesting are 3-D assemblies of ellipsoidal particles, which form structures similar to the liquid crystals. The methods of particles deposition will be presented, and the representative examples of hydrophilic spherical and ellipsoidal particle assemblies on surfaces with amine, hydroxyl and carboxyl groups will be discussed. The examples of crystalline materials obtained from the title particles will be presented.

Figure 1. Assemblies of spherical (Dn=300 nm, fPGLy=27.8 mol %) and ellipsoidal P(S/PGLy) particles deposited on silicon wafer containing anchored amine groups. Acknowledgements The work was financially supported by National Center of Science grant nr UMO-2014/13/B/ST5/04376. References [1] H. Shin, C. Kim. Colloid Polym. Sci. 2012, 290,1309–1315. [2] A.Yu. Menshikova, B. M. Shabels, N.N. Shevchenko, A.G. Bazhenova, A.B. Pevtsov, A.V. Sel’kin, A.Yu. Bilibin. Colloids Surf., A: Physicochem. Eng. Asp. 2007, 298, 27-33.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 PL 13. HYBRID MATERIALS BUILT OF SILICON-BASED POLYMERS Valeria Harabagiu*, Liviu Sacarescu ”Petru Poni” Institute of Macromolecular Chemistry, 41A Aleea Grigore Ghica Voda, 700487 Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Polysiloxane and polysilanes are themselves by nature hybrid polymeric materials where organic substituents are linked to inorganic Si-O-Si, respectively -Si-Si- chains. The chemical structure of both chain skeleton and organic substituents to silicon atoms is strongly influencing their properties. Thus, while the polydimethylsiloxanes are characterized by high flexibility, hydrophobicity and thermal resistance, the polysilanes are well known for the delocalization of σ-electrons along the polymeric chain, thus inducing electro-optical and semiconducting properties in the doped state. The coupling of silicon-based polymers with organic or inorganic moieties will further increase the spectrum of their properties and application. The presentation deals with the preparation and properties of polysiloxane and polysilane (co)polymers or networks [1-5], inclusion complexes of polysiloxanes into cyclodextrin macrocycles [3] and metal (or metal oxide)-polymer nanoparticles [4-6]. Figures 1 and 2 show some examples of the discussed hybrid systems.

Figure 1. Polysiloxane – cyclodextrin polyrotaxanes

Figure 2. Polysilane assisted synthesis of gold nanoparticles

Acknowledgements: the work was partially supported by of the project STHEMWOTB, contract MENCSUEFISCDI no.59/2014. References [1] A.C. Humelnicu, V. Harabagiu, C.A. Peptu, M.-M. Leon, F. Mitu, E. Cojocaru, A. Boca, B.I. Tamba, Curr. Pharm. Design 2015, 21, 6125-6139. [2] M. Soroceanu, A.I. Barzic*, I. Stoica, L. Sacarescu, V. Harabagiu; Express Polym. Lett. 2015, 9(5), 456468. [3] M. Soroceanu, L. Sacarescu, E.G. Hitruc, C. Ursu, V. Harabagiu, Int. J. Polym. Anal. Charact. 2014, 19(6), 482-488. [4] C. Miron, M. Balan, L. Pricop, V. Harabagiu, I. Jepu, C. Porosnicu, C.P. Lungu, Plasma Proc. Polym. 2014, 11(3), 214-221. [5] V. Totolin, N. Ranetcaia, V. Hamciuc, N. Shore, N. Dörr, C. Ibanescu, B.C. Simionescu, V. Harabagiu, Tribology Int. 2013, 67, 1-10. [6] L. Sacarescu, M. Simionescu, G. Sacarescu, V. Harabagiu, J. Inorg. Organomet. Polym. Mater. 2013, 23(3), 621-628. [7] G. Sacarescu, E. Taran, B.C. Donose, M. Simionescu, V. Harabagiu, L. Sacarescu, Polym. Int. 2012, 61(12), 1726–1732.

Book of abstracts

KEYNOTE LECTURES

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 KN 1. NANOCOMPOSITE WO3-TIO2/FLY ASH WITH DUAL FUNCTIONALITY IN SIMULTANEOUS REMOVAL OF POLLUTANTS FROM WASTEWATER Visa Maria*, Chelaru Andreea, Anca Duta Transilvania University of Brasov, Product Design and Environment, Colina Street, Brasov, Romania *E-mail: [email protected]

The present research focused on the preparation of TiO 2-WO3/FA composite with activity in adsorption and photocatalysis for to remove two industrial dyes (used in textile industry) and heavy metals under UV light. The composites were prepared from fly ash and sem iconductors by hydrothermal method for achieving a homogeneous distribution of the components within the composite. Fly Ash resulted from burning coal or biomass is a mixture of oxides with unburned carbon and other minority inorganic compounds thus has a predominant negative surface charge and represents a promising adsorbent for wastewater with complex composition. The individual WO3 and TiO2 nanocrystals were obtained either by sol-gel. The produced nanomaterials were characterized in terms of crystallinity (XRD) and surface properties: morphology and composition (AFM, SEM, EDS) wettabiliry (contact angle measurements), specific surface (BET) and FTIR. Major differences in their photocatalytic/adsorption activity performance depended on the nature of the precursors and the synthesis pathway. The adsorption capacity and photocatalytic properties of the composites were tested on mono and multi-pollutants systems containing two dyes (Bemacid Blau -BB and Bemacid Rot- BR) and one heavy metal ion-Cu2+, the optimized process conditions were identified. The initial and residual dye concentrations in the aqueous solution was analyzed by UV-VIS spectrometry (Perkin Elmer Lambda 25), on the calibration curve registered at the maximum absorption peaks of BB (λ=629 nm), and BR (λ=501 nm), while the heavy metal concentration was analyzed by AAS (Analytic Jena, ZEEnit 700), at λCu =324.75nm,respectively The results indicate better removal efficiencies using the novel composite material in the combined adsorption and photocatalysis, as compared to the separated processes. Dyes removal was significantly enhanced in the photocatalytic process by adding hydrogen peroxide. The parameters (contact time, amount of substrate and initial concentration of the pollutants) were optimized for obtaining a maximum efficiency and were further used in thermodynamic and kinetic studies, comparatively discussed with the photocatalysis optimized operating par ameters. The pseudo second order kinetics model best fitted the experimental data, both in the adsorption and in the combined process. The kinetic parameters were calculated and correlated with the properties of the composite substrate. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project number PN-II-RU-TE-2012-3-0177/2013.

Book of abstracts KN 2. CATION – SURFACTANT INTERACTIONS IN SMALL DROPLETS UNDER A TEMPERATURE GRADIENT Anca Duta* Transilvania University of Brasov, R&D Centre: Renewable Energy Systems and Recycling, Eroilor 29, 50036, Romania, *E-mail: [email protected]

The chemical deposition techniques allow obtaining thin films in low cost, up-scalable processes. Spray pyrolysis deposition (SPD) is one of the already used method, implemented at industrial level, basically for coating applications. However, in solar-energy conversion systems, the semiconductor thin films requires more accurate control of composition, crystallinity, polymorphism, morphology and wetting properties to get the targeted output properties (optical and/or electric). These set of properties should be mainly reached during deposition and can be further improved through thermal treatments. Thus, controlled nucleation and growth is of outmost importance and fine tuning can be done using templating agents, as surfactants or polymers. One specific feature of SPD that raises challenges in properties control is related to the technique as such: the small drops of the atomized precursor system continuously increase their temperature while approaching the heated plate where pyrolysis occurs, and, according to their volatility, the droplets will shrink, increasing the actual concentrations of all components. Thus significant changes occur between the precursor cation - surfactant(s) interactions, changing the template and modifying the nucleation pattern (and kinetics) during deposition (Fig. 1).

Fig. 1. Influence of the surfactant concentration on the cation-SDS interactions in SPD The paper discusses these aspects considering the thermodynamic correlations and analyses the control properties in two common precursor systems involving SDS; the cation influence (size, polarizability) is also outlined based on morphology results, for the TiO 2 and WO3 as deposited thin films. Acknowledgements This work was performed using financial support provided by the Project: PNII-PCCA, NANOVISMAT ctr. No. 162/2012.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 KN 3. POLYELECTROLYTE COMPLEXES AS COLLOIDAL DISPERSION COMPLEX TEMPLATES FOR CaCO3 CRYSTALS GROWTH Marcela Mihai*, Stefania Racovita, Florica Doroftei, Ana-Lavinia Matricala, Cristian Barbu-Mic “Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487, Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy An important method of biomimetic synthesis consists in the use a soft organic templates to control the morphogenesis of inorganic materials with complex forms. Due to its abundance in nature [1], calcium carbonate – a biocompatible inorganic material – received considerable interest for industrial applications (coatings, fillers, and components of drug and personal care formulations), and in environmental applications, for its potential application in carbon-capture [2]. In addition to a high natural abundance, it exhibits a unique combination of properties which include pH sensitive decomposition, nontoxicity, biocompatibility, low cost, and thus it is considered as a potential delivery vehicle for compounds such as drugs and proteins [3]. Even if numerous studies deal with polyanions control of CaCO 3 growth and with the polyanions used in this study, to our knowledge, except our previous study, no reports on the use of insitu mixing of complementary polyelectrolytes as templates for controlling CaCO 3 crystals growth have been published. There, we investigated composite calcium carbonate microparticles formation from supersaturated inorganic aqueous solutions in the presence of some strong/weak anionic polymers or nonstoichiometric polyelectrolyte complexes (NPEC) dispersions with excess anionic charges, and with low molar ratio between charges (0.2 and 0.4, respectively) [4]. The aim of this study was to follow the effect of mixed anionic/cationic polyelectrolytes on the crystallization of calcium carbonate in supersaturated solutions as compared to polyanion based-CaCO3 composite structures [5]. The method of introducing the polycation in the crystallogenesis of calcium carbonate has been also investigated: in-situ mixing of complementary polyelectrolytes or using nonstoichiometric polyelectrolyte complexes. For this purpose three polyanions, which contain weak – polyacrylic acid sodium salt, PAA – or strong anionic groups – poly(sodium 4-styrenesulfonate), PSS and poly( sodium vinylsulfonate), PVS – and poly(diallyl-dimethylammonium chloride), PD as polycation were used. Different molar ratio between complementary polyelectrolytes (n+/n-) were used in CaCO3 composite synthesis – from 0 (just polyanions) to 0.8. Composite particles characteristics as a function of polyanions structure and the preparation mode were evidenced by scanning electron microscopy (SEM) (Figure 1), FTIR-ATR spectroscopy, and energy dispersive X-ray diffraction (EDAX). + + + + + + + + +

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Figure 1. SEM images and schematic representation of composite microparticles based on CaCO 3 and different polymeric templates The particles morphology after dialysis against ethylenediamine tetraacetic acid (EDTA) has been also followed, as a function of molar ratio between complementary polyelectrolytes and preparation mode. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS – UEFISCDI, project number PN-II-RU-TE-2014-4-1433. References [1] F. C. Meldrum, H. Colfen, Chem. Revs. 2008, 108, 4332-4432 [2] A. C. Mitchell, K. Dideriksen, L. H. Spangler, A. B. Cunningham, R. Gerlach, Environ. Sci. Technol. 2010, 44, 5270-5276. [3] D. V. Volodkin, N. I. Larionova, G. B. Sukhorukov, Biomacromolecules 2004, 5, 1962-1972. [4] M. Mihai, S. Schwarz, F. Simon, Cryst. Growth Des. 2013, 13, 3144−3153. [5] M. Mihai, S. Schwarz, F. Doroftei, B. C. Simionescu, Cryst. Growth Des. 2014, 14, 6073−6083.

Book of abstracts

ORAL COMMUNICATIONS

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 1. HYBRID BIOMATERIALS - CHALLENGES AND OPPORTUNITIES Geta David1*, Tudor Vasiliu1, Daniel Tampu2, Dragos Peptanariu2, Cristina Uratu2 1”Gh.

2“Petru

Asachi” Technical University of Iasi, Bd. D. Mangeron, 71A, 700055 Iasi, Romania Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania *E-mail : [email protected]

Combining different materials in order to achieve the appropriate performances requiered for the applications in the envisaged domains is one of the strategies used to obtain biomimetic materials for biomedical uses, one of the topical research goal. Biocomposites or inorganic/organic (nano)composites are amongst the most studied biomaterials. However, to reach the envisaged level of functionality, together with hybrid material stabilityand processing ability, is often a real challenge, beginning with the selection of the components and of the preparative method. In this context, here some results are presented on the preparation, characterization and possible uses of hybrid materials generated by combining the most important components of the extracellular matrix -collagen and glycosaminoglycans- and synthetic polymers, in order to yield functionality, biocompatibility, together with processability, tailored mechanical stability and degradability. Making use of the versatility of such complex materials, these were trandformed in 3D matrices with tuned chemical, physical and morphological characteristics, or in multifunctional multilayered nanoparticles (Scheme 1). Preliminary data on the inclusion of non-viral gene carriers in porous 3D-matrices to give combined gene delivery systems, considered the most promising for clinical application, are presented.

Scheme 1. Hybrid biomaterials based on natural and synthetic polymers and nano-hydroxiapathite. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project number PN-II-ID-PCCE-2011-2-0028.

Book of abstracts OC 2. HYDROPHOBIZATION OF GLASS SURFACE BY ELECTROSTATIC DEPOSITION OF ALKYL-GRAFTED POLY(ACRYLATES)-SURFACTANT COMPLEXES Ioana Cătălina Gîfu*, Alina Iovescu, Monica Elisabeta Maxim, Elena-Livia Simion, Ludmila Aricov, Dan-Florin Anghel “Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, 060021 Bucharest, Romania, Tel/Fax: ++40213121147 *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Wettability is an important property of solid surfaces, which is affected by their chemical composition and geometrical microstructure [1]. Hydrophobic surfaces have low wettability and this make them useful for analytical, environmental and medical applications, antiseptic nanostructures, and many others. The present study demonstrates that hydrophobic glass can be obtained by using poly(electrolyte) multilayer films with a hills and valleys geometry. Self-assembled multilayered films were prepared by alternate deposition of poly(diallyldimethylammonium chloride) (PDADMAC) and hydrophobically modified poly(acrylate) (HMPA) in the presence and absence of surfactants and inorganic salt. The influence of the number of adsorbed layer, concentration of salt and the alkyl chain lengths grafted on the polymer and of surfactant was examined. Contact angle (CA) measurements reveal that films obtained with poly(acrylates)surfactant complexes are better water repellants than those without surfactant. For example, in Figure 1 are presented the AFM images and CA profiles for polyelectrolyte films and for polyelectrolyte-surfactant complexes. Salt addition into the dipping solutions gives rise to thinner films and less-coarse surfaces as witnessed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), data that will revealed during the presentation.

Figure 1. 2-dimensional topographic AFM images of: (a) (PAC18Na/PDADMAC) (RMS=1,42 nm), (b) (PAC18Na-C18TAB/PDADMAC) (RMS=14.39 nm) for 1 bilayer . Acknowledgements This paper has been financially sustained by the Romanian Academy within the research program „Colloids and dispersed systems” of the „Ilie Murgulescu” Institute of Physical Chemistry. The authors gratefully acknowledge the support of EU (ERDF) and Romanian Government allowing for acquisition of the research infrastructure under POS-CCE O2.2.1 project INFRANANOCHEM, No. 19/2009.03.01 and of PN-II-IDPCE-2011-3-0916 grant. References [1] T. Bharathidasan, V. Kumar , M.S. Bobji , R.P.S. Chakradhar, B.J. Basu, Appl. Surf. Sci., 2014, 314, 241-250.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 3. POLYION-DRIVEN SELF-ASSEMBLY OF SPHERICAL VIRUS-LIKE NANOPARTICLES INVESTIGATED BY MOLECULAR DYNAMICS SIMULATIONS Daniel G. Angelescu* Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, Splaiul Independentei 202, Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy As the simplest definition, a virus consists of a protein capsid surrounding an encapsulated nucleic acid or another cargo molecule, such as a synthetic polymer or an inorganic nanoparticle. The virus capsids are highly dynamic structures that self-assemble from numerous copies of one or slightly different proteic units, called capsomers, into varying geometries and sizes. They are spherical-like or cylindrical aggregates whose sizes are much smaller than the linear size of the virus genome. Most of the former structures possess icosahedral symmetry and therefore the capsids are limited by the geometric constraint that the capsomers to be arranged into a regular polyhedron. The encapsulation mechanism depends pronouncedly on the genome nature: i) viruses with flexible single stranded genome (ssRNA) assemble spontaneously from free capsomers and genome; ii) the much more stiffened double stranded genome (dsDNA) is loaded in a pre-formed empty capsid. Molecular dynamic investigations of a coarse-grain model describing the self-assembly of a viruslike nanoparticle with icosahedral symmetry in the presence of an oppositely charged linear and flexible polyion will be presented. Depending on the polyion length and the strength of capsomer-capsomer interaction, the simulations predict complex morphologies, including icosahedral capsules or disordered assemblages enclosing either completely or partially the polyion. The assembly kinetics is characterized in terms of the time-dependent cluster size and polyion extension and the structural properties of the resulting virus-like nanoparticle are quantified by means of the symmetry and radial distribution of the polyion.

a) b) c) Figure. a) Model system of a single triangular capsomer and b) snapshot and c) cut-section revealing the assembly of 20 capsomers around a linear flexible polyion consisting of 100 segments. Spheres with specific interactions are colored as follows: i) capsomer: red – soft repulsive beads, white and green – attractive beads, light blue – positively charged beads and ii) polyion: yellow – negatively charged beads

Acknowledgements The support of Romanian National Authority for Scientific Research, CNCS–UEFISCDI, through the project number PN-II-RU-TE-2012-3-0036, is acknowledged. References [1] R. Zhang, P. Linse, J. Chem. Phys. 2014, 140, 244903. [2] J.D. Perlmutter, C. Qiao, M.F. Hagan, eLife 2013, 2, e00632.

Book of abstracts OC 4. HYDROGEN BONDED COMPLEXES BETWEEN POLY(N-VINYLCAPROLACTAM) AND A MALEIC ACID COPOLYMER – INTERACTION STUDY AND APPLICATION IN DRUG DELIVERY Irina Popescu* “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda, 700487 Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy The poly(N-vinylcaprolactam) / poly(maleic acid-alt-styrene) (PVCL / MAc-St) system was investigated in dilute aqueous solution, when hydrogen-bonding interactions between COOH groups of MAc-St and C=O groups of PVCL, together with hydrophobic interactions are involved in the formation of the complex. The influence of the pH, the added salt and the ratio between the components on the precipitation of the complex was study. The critical pH value increase with the addition of inorganic salt from 2.85 in pure water to 4.95 in 0.01 M NaCl. An unexpected behavior was the presence of two maxima when the optical density of the mixed solutions were plotted against the mixing ratio (Figure 1). The same system was study in solution, at pH higher than the critical pH, by potentiometry, viscometry and fluorescence of pyrene probe in order to acquire further information about the interaction between the polymers. The phase transition of the thermosensitive PVCL in the presence of MAc-ST was also studied (Figure 2). This influence have been shown to depend in large extend by the pH. In order to study the potential use of this system in controlled drug delivery, spherical beads were prepared by complexation of MAc-St and PVCL in acidic medium (Figure 3). The beads were loaded with metoclopramide as a model drug. The pH and the ionic strength of the medium have been shown to influence the drug release profile (Figure 4) by controlling the dissolution of the complex.

Figure 1. The effect of the pH on the optical density of MAc-St / PVCL equimolecular mixture in pure water and at the addition of salt

Figure 2. The influence of the MAc-St addition on the cloud point of PVCL aqueous solution at pH = 4.5 and 3.5

Figure 3. SEM image of MAc-St/PVCL beads

Figure 4. Drug release profiles from MAcSt/PVCL beads in two buffer solutions

Acknowledgements This work was supported by a grant of the Romanian Ministry of Education, CNCS – UEFISCDI, project PN-RU-TE-2014-4-0437

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 5. TRANSIENT POLYMER NETWORKS FORMED IN SOLVENT. DOSY NMR AND RHEOLOGICAL INVESTIGATIONS Monika Gosecka*, Mateusz Gosecki, Slawomir Kazmierski Centre of Molecular and Macromolecular Studies of Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland *E-mail: [email protected]

The presence of numerous 1,2-diol functional groups in the peripheral area of the hyperbranched polyglycidol (HbPGL) macromolecules enabled to apply this polymer for the formation of hydrogel systems in the reaction with small molecular boronic crosslinking agents, i.e., benzene-1,4-boronic diacid and B(OH)4Ө ions. The reversible character of this reaction assures that obtained materials exhibit self-healing properties [1]. Due to the fact that crosslinking reaction is sensitive to pH [2], it was essential to elaborate the optimal conditions for hydrogel formation, including the concentration of crosslinker, which significantly influences the hydrogel formation. DOSY NMR experiments carried out for semi-diluted solutions lead to the significant reduction of the required amount of polymer necessary for elaboration of pH and crosslinker/polymer ratio for the formation of the hydrogel of desired characteristics. These results were verified with rheological characteristics of samples prepared at analogical conditions, though applying more concentrated polymer solutions. Generally, when diffusion coefficient of polymer objects was above 6.60·10 -11 m2/s (the average molecular volume of objects below 75.0 nm 3), the gel formation was not possible. It is evident that the higher the reduction of diffusion coefficient of macromolecules is, the higher crosslinking density within hydrogel is observerd on the basis of the increase in the maximum of storage modulus plateau. The maximum of storage modulus at high frequencies is gradually increasing with the concentration of boronic crosslinker (Figure 1), as the number of covalent junctions per one macromolecule is rising.

Figure 1. G'max (ω) of hydrogels versus diffusion coefficient of polymer objects present in solution containing polymer with crosslinker at various pH and molar ratio of diol functional groups per one boronic acid site. Generally, DOSY NMR and rheological investigations revealed that benzene-1,4-boronic diacid is more efficient agent in HbPGL crosslinking than inorganic B(OH) 4Ө ions. Moreover, the combination o NMR and DOSY NMR results was helpful to state that intramolecular crosslinking within a single HbPGL macromolecule is not a favourable process. References [1] E.B. Stukalin, L.-H. Cai, N.A. Kumar, L. Leibler and M. Rubinstein, Macromolecules 2013, 46, 75257541 [2] M. van Duin, J.A. Peters, A.P.G. Boom, H. van Bekkum, Tetrahedron 1984, 40, 2901-2911

Book of abstracts OC 6. FLUORESCENCE INVESTIGATION OF HYDROPHOBICALLY MODIFIED POLYACRYLATES IN AQUEOUS SOLUTION AND IN THE PRESENCE OF SURFACTANTS Ludmila Aricov*, Adriana Băran, Elena Livia Simion, Ioana Cătălina Gîfu, Dan-Florin Anghel “Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Water-soluble hydrophobically modified sodium polyacrylates (NaPAC n) were synthesized by grafting the poly (acrylic acid) (PAA) with 3 % (mol) C10 and C18 linear alkyl side-chains. The photopshysical properties of the NaPACn and their mixtures with surfactants were investigated by fluorescence spectroscopy, using pyrene as a probe. Cationic, anionic and nonionic surfactants with the same alkyl chain length (i.e., C12) were employed. The steady-state fluorescence results proved that the sodium polyacrylate (NaPA) does not have hydrophobic microdomains to accommodate pyrene inside. Instead, the NaPAC ns unveiled intracoil aggregates at a certain polymer concentration which decreases with the alkyl chain length. For aqueous grafted polyacrylate solutions, the dynamic fluorescence proved the existence of both intra- and intercoil aggregates, because the pyrene lifetimes have various values in the different microdomains (Figure 1). The association of unmodified and modified polymers with surfactants are strongly dependent on the presence of hydrophobic microdomains and the surfactant nature. Therefore, the hydrophobic interactions play an important role, especially for the NaPAC18 – surfactant systems due to the low polarity of the polymer. It was also observed that the cationic surfactant strongly interact with the polymers, while the anionic one hardly did. The nonionic surfactant had an intermediate association behavior. For the mixed systems, the lifetimes of the probe were not much affected by the cationic and nonionic surfactants.

Figure 1. The modification of fluorescence lifetimes with polymer concentration Acknowledgements The research has been financially supported by the Romanian Academy within the research programme „ Functional Complex Colloids” of the „Ilie Murgulescu” Institute of Physical Chemistry. The support of EU (ERDF) and Romanian Government (POS-CCE O2.2.1 project INFRANANOCHEM, No. 19/2009.03.01) and of (UEFISCDI) (Project PN-II-ID-PCE-2011-3-0916, Contract No. 177/2011) is gratefully acknowledged.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 7. INFLUENCE OF THE C12 SURFACTANTS CONCENTRATION ON THE MORPHOLOGY OF SPRAY PYROLYSIS DEPOSITED ZnO Maria Covei*, Cristina Bogatu, Dana Perniu, Anca Duta "Transilvania" University of Brasov, Bd. Eroilor, no. 39, 500036, Romania *E-mail: [email protected]

Surfactants are materials that behave differently in solutions above and below a certain concentration, named the critical micelle concentration (CMC). Below this value, surfactants mainly stick to the surface/interface or can be randomly distributed into the solvent, whereas above it, they form aggregates (micelles) in the colloidal size range. Given the importance of the CMC, its value is well-known for the most largely-used surfactants in aqueous solution, at room temperature. However, surfactants’ CMC in disperse systems that also include electrolytes and a combination of water–organic solvent will lead to completely different behavior, both in terms of CMC and of the micelles shape. Spray pyrolysis deposition (SPD) is a thin film chemical deposition method that uses a precursor solution which is dispersed through an atomizer by a carrier gas under pressure. The atomized droplets are carried to a heated substrate, where the solvent evaporates. Thin films form as a result of the cation precursor adsorption on the substrate, followed by reaction (e.g. with the oxygen in air), while the volatile by-products are removed by evaporation. Surfactants will therefore have a multiple effect: on the droplets size (by changing the surface pressure), in the precursor system by interacting with the precursor cation and further on, during film nucleation and growth, by modifying the kinetics of the cations-surfactant complex. Although organometallic precursors are mentioned, sustainable and low cost SPD processes use inorganic metallic salts as thin film precursors. The paper discusses the influence of the precursor system composition on the CMC of three surfactants, with linear C12 tail, in a water-ethanol mixture of different ratios (2:1, 1:1 and 1:2) for the anionic sodium dodecyl sulfate (SDS), the cationic dodecyl trimethyl ammonium bromide (DTAB) and the non-ionic dodecanol (DD). A precursor systems is investigated, containing zinc acetate, usually selected to obtain ZnO through SPD. Moreover, acetylacetone (AcAc) is added into the system to lower the solution viscosity. Complex-type structures (Zn-AcAc, Zn-surfactant and/or AcAc-Zn-surfactant) are developed, both in the bulk precursor system and in the atomized drops. The critical micelle concentration was experimentally measured using conductometry. The three surfactants were further added in concentrations higher and, respectively lower than their CMC and the surfactant type and concentration was correlated with the morphology and wetting properties of the SPD deposited films. It was found that the interactions between the surfactants, the zinc precursor and acetyl acetone are strongly dependent on the surfactant head: there is a much stronger attraction between ZnAcAc complex structures and SDS, compared to those involving DTAB or DD, which takes place through a double layer. This affects the size, stability and distribution of the larger molecules (both pre- and postmicelles) in the precursor solution and sprayed droplets, which in turn affects the growth kinetics and/or mechanisms, allowing to tailor the surface morphology, as Figure 1 shows.

(a) (b) (c) Figure 1. Micrographs of ZnO thin film obtained using: (a) SDS at concentrations lower than CMC; (b) DTAB at concentrations lower than CMC; (c) DTAB at concentrations higher than CMC. Acknowledgements This work was performed using financial support provided by the Project:M-ERA-NET „Watersafe” 117847.

Book of abstracts OC 8. ALGINATE / SPINEL FERRITE COMPOSITE AS MAGNETIC ADSORBENT FOR ENVIRONMENTAL APPLICATIONS Andra-Cristina Humelnicu*, Corneliu Cojocaru, Petrisor Samoila, Petronela Pascariu Dorneanu, Valeria Harabagiu "Petru Poni" Institute of Macromolecular Chemistry, Grigore Ghica Voda Aley, 41A, 700487 Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of Romanian Academy Adsorption is an efficient purification technique for the removal of dyes from wastewaters [1]. However, the separation of the spent adsorbents still remains a drawback. In this regard, the magnetic separation has recently attracted attention as a feasible alternative for common separation methods. The objective of this work was to develop efficient alginate / spinel ferrite composites as magnetic adsorbents for the removal of cationic dyes from aqueous solutions. Pure NiFe2O4 was prepared by the sol-gel auto-combustion method [2] using citric acid as a fuel agent. The crystal structure and surface morphology of the inorganic material (NiFe2O4) were characterized by infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The composite materials were prepared from alginate aqueous solutions (2-3% w/w) and diluted ferrofluid obtained by NiFe2O4 dispersion under ultrasonication in water. The resulted alginate/NiFe 2O4 solutions were cast on Petri dishes following the solvent evaporation. The obtained membranes were subsequently cross-linked in CaCl2 aqueous solutions (0.05 – 0.15M). Next, membranes were cut and grinded to obtain composite powders with average particle size of about 500 µm. The content of inorganic magnetic support (NiFe2O4) in composite varied into the range of 15-25% w/w. The alginate materials were characterized by infrared spectroscopy (Fig.1). The produced composite adsorbents (Ca-alginate/ NiFe2O4) were applied for the removal of the cationic dye (Rhodamine-6G) from aqueous solutions containing 50 mg/L initial dye concentration. The experiments were carried out according to a full factorial design, and the adsorption process was monitored by UV-VIS method (526 nm). Consequently, a multivariate regression model was developed to predict the adsorption capacity (q, mg/g) of materials as a function of controllable factors (i.e. alginate concentration, amount of NiFe2O4 and CaCl2 concentration). The developed mathematical model in terms of actual variables is given as follows: qˆ  8.3  4.51C1  0.18C2  41.7C3  0.046C1C2  25.1C1C3  1.44C2 C3 (1) subject to: 2.0≤(C1 :Alginate)≤3.0 % w/w; 15≤(C2 : NiFe2O4)≤25 % w/w; 0.05≤(C3 :CaCl2)≤ 0.15 M The response surface plot showing the effect of factors on the material’s response (i.e. adsorption capacity) is depicted in Fig.2. The model-based optimization enabled to find the optimal composition of the material (i.e., C1=3% w/w; C2=15% w/w and C3=0.05M) that ensured the highest adsorption capacity of q = 19.7 mg/g.

Figure 1. FTIR spectra of alginate-based materials.

Figure 2. Response surface plot: q vs. (C1 and C3 )

Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS – UEFISCDI, project number PN-II-RU-TE-2014-4-1266. References [1] E.N. El Qada, S.J. Allen, G.M. Walker, Chem. Eng. J. 2006, 124, 103-110. [2] P. Samoila, C. Cojocaru, I. Cretescu, C.D. Stan, V. Nica, L. Sacarescu, V. Harabagiu, J.Nanomater., 2015, ID 713802, 1-13.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 9. BORAX COMPLEXES STARTING FROM ANIONIC SURFACTANT IN ASSOCIATION WITH UNLABELED OR FLUORESCENTLY LABELED POLY(ACRYLIC ACID)S Elena Livia Simion*, Gabriela Stîngă, Adriana Băran, Ludmila Aricov, Ioana Cătălina Gîfu, Dan Florin Anghel Department of Colloids, “Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, 060021 Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Interactions between polymers and surfactants is a topic of great interest, due to their use as colloidal systems stabilizers, rheology modifiers, emulsifiers or flocculating agents in products such as cosmetics, food, medicines, detergents or paints. Inorganic salts can moderate the electrostatic effect influencing the surfactant-polymer association. On the other hand, borax has found applications in a large diversity of fields including detergents, soaps, medicine, optoelectronics, hydraulic fluids for oil recovery, metallurgy, ceramics and glass, insecticides, etc. In this study we evaluated borax’s effect upon sodium dodecyl sulfate (SDS)-poly(acrylic acid) (PAA) complexes. Comparison was made by using both unmodified and fluorescently modified polymers. Also, the effect of sodium chloride versus borax on the polymer-surfactant complexes was followed. To this end, a poly(acrylic acid) with molecular weight of 25000 was grafted with 2.4 % 1-naphthylmethylamine (PAA25Np42). Surface tension, and conductivity measurements reveled that both naphthyl tag and borax reinforce the interaction between SDS and polymer. The photophysical data (polarity index, excimer formation and lifetimes) obtained from steady-state and time-resolved fluorescence measurements gave insight on the nanostructures formed between the weak polyelectrolyte and the anionic surfactant. Figure 1 shows the ratio of monomer to excimer intensity (IE/IM) for the grafted polymer which can be used as a measure of the self-association of the aromatic groups, as well as a conformational index of the polymer chain.

without salt -3 M NaCl -5 1.3x10 M borax -3 5x10 M borax

0.44

5x10

0.40

IE/IM

36

0.36

0.32 -3

-2

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Figure 1. Variation of IE/IM of PAA25Np42 versus SDS concentration without salt, in presence of 1.3x10-5 M or 5x10-3 M borax, as well as 5x10-3 M NaCl. Acknowledgement This paper was carried out within the research program Colloids and Dispersed Systems of the Ilie Murgulescu Institute of Physical Chemistry, financed by the Roumanian Academy. The authors gratefully acknowledge the support of the EU (ERDF) and Roumanian Government allowing the acquisition of research infrastructure under POSCCE O 2.2.1 project INFRANANOCHEM – Nr. 19/01.03.2009 and of The Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI), Project PN-II-ID-PCE-2011-3-0916, Contract No. 177/2011.

Book of abstracts OC 10. OSMOLYTES EFFECT ON THE STRUCTURE AND KINETICS OF CANDIDA RUGOSA LIPASE ENCAPSULATED IN REVERSE MICELLES Anca Ruxandra Leonties1, Gabriela Stângă1, Adina Răducan2, Dan-Florin Anghel1 1”Ilie

Murgulescu” Institute of Physical Chemistry, Spl. Independenței 202, Post Office 12, P.O. Box 194 060021, Bucharest, Romania 2 Faculty of Chemistry, University of Bucharest, Bd. Elisabeta 4-12, 030018, Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Nowadays, the enzyme stability is an important task of research. Naturally occurring osmolytes can be used as proteins stabilizers. This study is focused on the effect of trehalose, myo-inositol and phytic acid on the structural stability and activity of Candida rugosa lipase. Spectroscopic insights were revealed on the structure of lipase using UV-Vis, steady-state fluorescence and circular dichroism. Also, the kinetics of lipase-catalyzed hydrolysis of olive oil in reverse micellar media in the presence of osmolytes was studied. The fluorescence results show that the structure of lipase is modified by osmolytes in aqueous and micellar media. Circular dichroic spectra indicated that the protein undergoes some conformational changes upon interacting with these osmolytes (Figure 1). The kinetics of the enzyme encapsulated in reverse micelles in the presence of trehalose, myo-inositol and phytic acid differ from those when none of the additives were present. Lipase exhibits “superactivity” in reverse micelles when trehalose and myo-inositol are present and the activity is significantly lowered by the phytic acid. Results of this study could give further insights about the enzyme stabilization mechanism. 10

((mdeg)

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-20

-30 200

210

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Figure 1. Circular dichroic spectra of aqueous lipase in the presence of trehalose (★), myo-inositol (▲), water (■) and phytic acid (●) Acknowledgements This study was carried out within the research programme „Complex Functional Colloids” of the „Ilie Murgulescu” Institute of Physical Chemistry, financed by the Romanian Academy. The authors gratefully acknowledge the support of EU (ERDF) and Romanian Government allowing for acquisition of research infrastructure under POS-CCE O 2.2.1 project INFRANANOCHEM, No. 19/2009.03.01, and of PN-II-ID-PCE-2011-3-0916, No. 177/2011 project.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 11. ANTIVIRAL EFFECT AGAINST HEPATITIS B VIRUS OF NANOCOMPOSITES SELFASSEMBLIES OF PLASMONIC GOLD/LAYERED DOUBLE HYDROXIDES Gabriela Carja1*, Elena Florentina Grosu1, Catalina Petrareanu2, Norica Nichita2 1Department

of Chemical Engineering, Faculty of Chemical Engineering and Environmental Protection, Technical University “Gh. Asachi” of Iasi, Bd. Mangeron No. 71, Iasi 700554, Romania. 2Department of Viral Glycoproteins, Institute of Biochemistry of the Romanian Academy, Splaiul Independentei 296, Bucharest 060031, Romania *E-mail: [email protected]

The design of complex nanocomposites engineered to interact with cells and to specifically act against hepatitis B virus (HBV) is a challenging approach in the conditions that the current therapies against HBV infections have limited efficacy and serious side effects. Herein, the antiviral effect of the selfassemblies of plasmonic gold and layered double hydroxides (AuNPs/LDHs) is demonstrated, for the first time, using HBV as a model virus and the hepatoma-derived HepG2.2.215 cells supporting viral replication, assembly and secretion of infectious virions and subviral particles [1]. AuNPs/LDHs were obtained by a simple procedure in which small AuNPs (~ 3.5 nm) were directly obtained and organized on the surface of larger nanoparticles (150 nm) of LDHs by exploiting the capability of the specific compositions of MgLDH, ZnLDH and MgFeLDH to manifest their “structural memory” in the aqueous solution of Au(O2CCH3)3. The self-assembly approach of AuNPs and LDHs was studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD) and UV-Vis analysis (UV-Vis). All AuNPs/LDHs reduced the amount of viral and subviral particles released from treated cells by up to 80% and exhibited good cytocompatibility. AuNPs/MgFeLDH showed the highest antiviral HBV response with more than 90% inhibition of HBV secretion for the whole concentration range. With these antiviral properties and low cytotoxicity plasmonic gold/LDHs nanocomposites hold great potential to be tailored as novel efficient therapeutics for the treatment of hepatitis B.

Figure 1. HBV antiviral activity of AuNPs/ZnAlLDH. Acknowledgements The authors gratefully acknowledge the financial support from the Romanian National Authority for Scientific Research, CNCS-UEFISCDI; project number PN-II-IDPCE 75/2013. References [1] G. Carja, E.F. Grosu, C. Petrarean, N. Nichita, NanoResearch, 2015, 8/11, 3512-3523.

Book of abstracts OC 12. DESIGNING AND CHARACTERIZATION OF NOVEL IPN COMPOSITE CRYOGELS BASED ON POLY(N,N-DIMETHYLAMINOETHYL METHACRYLATE) AND POLY(ACRYLAMIDE) Ecaterina Stela Dragan*, Ana Irina Cocarta “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Living systems respond to external stimuli by adapting themselves to changing conditions. Smart polymers, defined as polymers that undergo reversible changes in response to small external changes in the environmental conditions, such as temperature, pH, magnetic or electric field, solvent composition, ionic strength and so on, have been designed to mimic this behavior. Smart polymers have various applications in the biomedical field as delivery systems of therapeutic agents, tissue engineering scaffolds, cell culture supports, bioseparation devices, sensors or actuators systems. Interpenetrating polymer networks (IPN) have been widely used last decade to generate more sophisticated and more efficient drug delivery systems. Temperature and/or pH responsive IPN composite hydrogels based mainly on polysaccharides and biocompatible synthetic polymers have attracted much of attention [1-6]. The aim of this study was to prepare novel IPN hydrogels by a sequential strategy consisting of the preparation first of a poly(N,N-dimethylaminoethyl methacrylate) (PDMAEM) cationic network, and then a poly(acrylamide) (PAAm) network by using N,N’- methylenebisacrylamide as cross-linker. Both networks were macroporous and generated by cryogelation technique. The presence of PDMAEM endows the cryogels with sensitivity at numerous external stimuli such as: pH, temperature, ionic strength, electric field, among which the first three will be discussed. IPN cryogels were characterized by scanning electron microscopy, and water uptake as a function of pH, temperature and ionic strength. The release of diclofenac sodium (DS) from the macroporous IPN composite cryogels was evaluated as a function of pH and temperature. It was found that at pH 7.4 the IPN cryogels present the highest percentage of DS release. The release mechanism of DS has been also evaluated. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCSIS – UEFISCDI, project number PN-II-ID-PCE-2011-3-0300. References [1] C.W. Peak, J.J. Wilker, G. Schmidt, Colloid Polym. Sci. 2013, 291, 2031. [2] E.S. Dragan, Chem. Eng. J. 2014, 243, 572. [3] N. Zhang, M. Liu, Y. Shen, J. Chen, L. Dai, C. Gao, J. Mater. Sci. 2011, 46, 1523. [4] Y. Liu, Y. Cui, J. Appl. Polym. Sci. 2011, 120, 3613. [5] E.S. Dragan, Pure Appl. Chem. 2014, 86, 1707. [6] E.S.Dragan, A.I. Cocarta, M. Gierszewska, Colloids Surf. B: Biointerfaces 2016, 139, 33-41.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 13. FLUORESCENTLY LABELED POLY(ACRYLIC ACID) IN CONFINED MICROENVIRONMENTS Gabriela Stîngă*, Adriana Băran, Alina Iovescu, Elena Livia Simion, Ludmila Aricov, Dan-Florin Anghel “Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, 060021, Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Pyrene-based materials are of major interest to designing organic electronic devices such as sensors, light emitting diodes, dye sensitized solar cells or to shed light on the structure of proteins, peptides, lipid membranes, etc [1-3]. Although there are many reports on the behavior of polymers in aqueous solutions without and with surfactant or in pure organic solvent, much less is known about their association in confined media like reverse micelles (RMs). This study reports on self-aggregation ability of pyrene labeled poly(acrylic acid)s with various graft content in sodium bis(2-ethylhexyl) sulfosuccinate RMs. The fluorescent response of label in water and in RMs is compared. The results obtained from UV-Vis, steady-state and time-resolved fluorescence show that the photophysical properties of the pyrene depend on the hydration degree, the concentration and the graft content of polymer. The emission data indicate that the crowded micellar media tune the formation of pyrene excimers (see Figure 1). New insights regarding the interactions and dynamics of the fluorescently labeled polymer in the nanoscopic micellar aqueous host are highlighted.

Fluorescence Intensity, [a.u.]

40

water w0 = 5

14

w0 = 7 w0 = 10 w0 = 15

7

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400

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Figure 1. Emission spectra of pyrene labeled poly(acrylic acid) obtained in RMs and in water for excitation wavelength of 350 nm

Acknowledgements This study was carried out within the research programme „Complex Functional Colloids” of the „Ilie Murgulescu” Institute of Physical Chemistry, financed by the Romanian Academy. The authors gratefully acknowledge the support of EU (ERDF) and Romanian Government allowing for acquisition of research infrastructure under POS-CCE O 2.2.1 project INFRANANOCHEM, No. 19/2009.03.01, and of PN-II-IDPCE-2011-3-0916, No. 177/2011 project. References [1] C. Suárez-Germà, L.M.S. Loura, M. Prieto, Ò. Domènech, J.M. Campanera, M.T. Montero, J. Hernández-Borrell, J. Phys. Chem. B, 2013, 117, 6741−6748. [2] K.T. Wong, D.M. Bassani, NPG Asia Materials, 2014, 6, 1-10. [3] K. Kaushlendra, S.K. Asha, J. Phys. Chem. B, 2014, 118, 4951−4962.

Book of abstracts OC 14. PHYSICALLY AND CHEMICALLY CROSS-LINKED CELLULOSE CRYOGELS Diana Ciolacu1*, Cyrielle Rudaz2, Tatiana Budtova2 1“Petru

Poni” Institute of Macromolecular Chemistry, Department of Physical Chemistry of Polymers, 11 41A Grigore Ghica Voda Alley, 700487, Iasi, Romania 2MINES ParisTech, PSL Research University, CEMEF - Centre de Mise en Forme des Matériaux, CNRS UMR 7635, CS 10207 rue Claude Daunesse 06904 Sophia Antipolis, France *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Porous cellulose matrices were prepared via dissolution in 8wt%NaOH-water, physical gelation and chemical cross-linking with epichlorohydrin (ECH), coagulation in water and lyophilisation. Gelation was either via physical (“aging” of cellulose solutions) or chemical (cross-linking with different amounts of ECH).Cellulose and cross-linker concentration were varied. A schematic presentation of the preparation steps is shown in Figure 1.

physical gelation

Cellulose8%NaOH-water solution

Cellulose gel

coagulation

Cellulose hydrogel

freeze-drying

Cellulose cryogel

chemical gelation

Figure 1. Schematic presentation of physically and chemically cross-linked cellulose cryogels The behavior of gels upon coagulation and the swelling of cryogels in water were analyzed. An anomalous high swelling at cross-linker concentration around stoichiometric molar ratio with cellulose was observed: while physical gels contract during coagulation in water and become opaque, chemically crosslinked gels swell and become transparent. Cellulose cryogel morphology, crystallinity and density were studied. NMR, XRD and DSC showed that the crystallinity of chemically cross-linked cellulose is lower than that of physically cross-linked counterparts, and it decreases with the increase of ECH concentration in solution. The results obtained allowed suggesting a hypothesis explaining the difference in structure formation during cellulose physical and chemical gelation Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS - UEFISCDI, project number PN-II-RU-TE-2014-4-0558. A part of this work was also financial supported by French National Agency for Research (ANR), “Nanocel” project ANR-09-HABISOL010.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 15. SORPTION/RELEASE OF IONIC COMPOUNDS IN/FROM POLY(ETHYLENEIMINE)/POLY(ACRYLIC ACID) MULTILAYER FILMS Claudiu-Augustin Ghiorghiță*, Florin Bucatariu, Ecaterina Stela Drăgan “Petru Poni” Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487, Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Layer-by-layer assembly is a versatile and eco-friendly method for coating substrates with polyelectrolyte multilayer (PEM) thin films having controlled architecture and functionalities [1]. The PEMs, either attached to the underlying substrates or as free-standing films, have been used extensively as delivery systems for numerous bioactive compounds, such as drugs, proteins or genes [2-4]. Herein, we investigate the sorption and release of ionic compounds in/from multilayer films assembled using poly(ethyleneimine) (PEI) and poly(acrylic acid) (PAA). First, PEI/PAA multilayer films deposited onto Daisogel microparticles were used for the sorption and release of the anionic dye Congo Red (CR). The sorption of CR by the composite microparticles was investigated as a function of the number of PEI layers deposited and on the cross-linking method used (thermal or with pyromellitic dianhydride). Furthermore, the composite microparticles showed a pH responsive release behavior of the sorbed dye. Afterwards, it was demonstrated the possibility to obtain free-standing PAA/PEI multilayer films using a mixt pH and solvent detachment procedure (Figure 1). For this purpose, poly(diallyldimethyl ammonium chloride) (PDADMAC) was used as sacrificial layer.

Figure 1. Schematic representation for the deposition, cross-linking and detachment steps used to obtain the free-standing PAA/PEI multilayer film. The free-standing PAA/PEI multilayer film showed a good capacity to sorb diclofenac sodium (DS), while the release was also pH responsive. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project number PN-II-ID-PCE-2011-3-0300. References [1] K. Ariga, Y. Yamauchi, G. Rydzek, Q. Ji, Y. Yonamine, K.C.W. Wu, J.P. Hill, Chem. Lett. 2014, 43, 36-68. [2] Z. She, M.N. Antipina, J. Li, G.B. Sukhorukov, Biomacromolecules 2010, 11, 1241-1247. [3] F. Bucatariu, C.-A. Ghiorghita, E.S. Dragan, Colloids Surf. B: Biointerfaces 2015, 126, 224-231. [4] F. Bucatariu, C.-A. Ghiorghita, E.S. Dragan, High. Perform. Polym. 2015, 27, 563-570.

Book of abstracts OC 16. NEW ASPECTS OF THE BINDING OF ETHOXYLATED NONIONIC SURFACTANTS TO SERUM ALBUMINS REVEALED BY SPECTROSCOPIC TECHNIQUES Alina Iovescu*, Adriana Băran, Gabriela Stîngă, Anca Ruxandra Leonties, Monica Elisabeta Maxim, Dan Florin Anghel Colloids Chemistry Laboratory, „Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Spl. Independentei 202, Sector 6, 060021 Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Hydrophobic attraction has been considered for long time ago the main, if not the solely force of interaction between the serum albumins and the nonionic surfactants [1,2]. Nowadays, more sensitive techniques may further enlighten these systems. In this communication we report the binding behavior of various levels of ethoxylated nonionic surfactants to a fixed serum albumin concentration. Mono-disperse tetra- (C12E4), hexa- (C12E6) and octaethyleneglycol mono n-dodecyl ether (C12E8), and poly-disperse eicosa-ethyleneglycol mono n-tetradecyl ether (C14EO20) are respectively considered. The investigation is done by fluorescence and circular dichroism. Pyrene probe also reports on these aqueous mixtures, as an extrinsic fluorophore. Circular dichroism data show that the content of protein α–helix increases in surfactant presence. Static fluorescence spectra allow constructing the binding isotherms of the homologous surfactants. The protein fluorescence quenches through a static mechanism and fluorescence lifetime determinations confirm it. New insights upon the mechanism of interaction are provided by the thermodynamic binding parameters in corroboration with the dichroic results. Beside hydrophobic attraction, hydrogen bonding appears as another driving force of the interaction between serum albumin and ethoxylated surfactants. The ethylene oxide (EO) moiety mediates the formation of new H bonds between the apt NH groups of protein, with novel α-helix construction, as sketched in Figure 1. The results reveal an optimum EO chain length for hydrogen bonding with the albumin. More details will be given during the presentation.

Figure 1. Additional α–helix development in the less ordered regions of serum albumin Acknowledgements The study has been financed by the Romanian Academy (research programme „Functional Complex Colloids” of the „Ilie Murgulescu” Institute of Physical Chemistry). The authors acknowledge the support of EU (ERDF) and Romanian Government allowing for acquisition of the research infrastructure under POSCCE O2.2.1, project INFRANANOCHEM, No. 19/2009.03.01 and the support from PN-II-ID-PCE-2011-30916 grant. References [1] N. Nishikido, T. Takahara, H. Kobayashi, M. Tanaka, Bull. Chem. Soc. Jpn. 1982, 55, 3085-3088. [2] H. Durchschlag, K.-J. Tiefenbach, R. Weber, B. Kuchenmüller, R. Jaenicke, Colloid Polym. Sci. 2000, 278, 312-320.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 17. THE INFLUENCE OF SEVERAL PARAMETERS UPON THE BEHAVIOR OF PYRENE LABELED POLY(ACRYLIC ACID) IN AOT REVERSE MICELLE AS REVEALED BY NRET Monica Elisabeta Maxim1*, Gabriela Stîngă1, Alina Iovescu1, Dan Eduard Mihăiescu2, Adriana Băran1, Anca Ruxandra Leonties1, Marieta Balcan1, Dan Florin Anghel1 1Colloids

Chemistry Laboratory, “Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Spl. Independenţei 202, 060021 Bucharest, Romania 2Organic Chemistry Department, Faculty of Applied Chemistry and Materials Science, “Politehnica” University of Bucharest, 1–7 Polizu Street, 011061 Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy The AOT/water/isooctane system was investigated by nonradiative energy transfer (NRET) between naphthalene (Np) dissolved in the organic solvent and pyrene grafted on poly(acrylic acid) (PAA150-Py32) solubilized in the reverse micelle. The phenomenon was strongly dependent on pH, hydration degree (w0), polyelectrolyte concentration and addition of salt. The UV-Vis measurements revealed polymer solubilization in the micellar nanocage. Specific interfacial interactions that can be correlated with the presence of the polymer at the oil/water interface are confirmed by FTIR. DLS results showed that the average hydrodynamic diameter (d h) of the formed aggregates increases with w0. This confirms that the polar groups area of the surfactant increases with the water content due to the steric effect of the alkyl chains [1]. Addition of increasing amounts of salt at constant w0, entails the decrease of dh. The phenomenon is due to the thinning of the electrical double layer of micelle [2]. By steady-state fluorescence the photophysical parameters of PAA150-Py32 (i.e., the polarity index, I1/I3 and the polymer conformation index, IE/IM) at different pH values were determined. For w0= 5, 7 and 10, I1/I3 increased with pH. IE/IM had a different behavior at smaller hydration degree (5, 7) than at higher hydration degree (10, 15). For w0 = 5, 7, as the micellar pH increases, IE/IM decreases from a pH value close to the pKa of the polymer and at w0 = 10, 15 the pH had no obvious influence upon the excimers formation. The emission of Py strongly depends on pH and NRET occurs for all studied pH values (Figure 1a). An efficient energy transfer in systems of this type is indicative for a stable oil-water interface. With increasing the polyelectrolyte concentration, at constant w0, the efficiency of NRET increases (Figure 1b). The acquired results shed more light upon the factors that affect the stability of micellar interface and allow useful industrial and biomedical applications. 150000

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Figure 1. NRET in the AOT/water/isooctane/PAA150-Py32/Np systems with: a) w0=10 at different pH values; b) w0=7, at different polyelectrolyte concentrations. Acknowledgements: This paper has been financially supported by the Romanian Academy within the research programme „Functional Complex Colloids” of the „Ilie Murgulescu” Institute of Physical Chemistry. The authors gratefully acknowledge the support of EU (ERDF) and Romanian Government allowing for acquisition of the research infrastructure under POS-CCE O2.2.1 project INFRANANOCHEM, No. 19/2009.03.01 and the support from PN-II-ID-PCE-2011-3-0916 grant. The contribution of Dan Eduard Mihăiescu has been funded by the Sectoral Operational Programme Human Resources Development 2007-2013 of the Ministry of European Funds through the Financial Agreement POSDRU/159/1.5/S/132397. References [1] R. M. Lynden-Bell, S.C. Morris, J.D. Barrow, J.L. Finney, C. Harper, Water and Life: The unique Properties of H2O, Ed. CRC Press Taylor & Francis Group, Boca Raton, U.S.A., 2010, p. 138. [2] H. Fathi, J.P.Kelly, V.R. Vasquez, O. A. Graeve, Langmuir 2012, 28, 9267-9274.

Book of abstracts OC 18. THE INFLUENCE OF THE CULTURE MEDIUM COMPOSITION ON THE EXOPOLYSACCHARIDE BIOSYNTHESIS Anca Roxana Petrovici*, Irina Rosca, Alina Nicolescu, Mariana Pinteala, Diana Ciolacu 1“Petru

Poni” Institute of Macromolecular Chemistry, Centre of Advanced Research in Bionanoconjugates and Biopolymers Department, 41A Grigore Ghica-Voda Alley, 700487, Iasi, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy The trend of orientation towards biopolymers and to design innovative products has led to a global resurgence of interdisciplinary research on bacterial exopolysaccharides (EPS). Lactic acid bacteria (LAB) are capable to biosynthesize EPS. The EPS biosynthesis is strongly related to the fermentations conditions like culture medium composition, aeration rate, fermentations time and temperature and agitations conditions. The fermentation process in different culture medium composition of the same LAB strain, maintaining all other fermentative parameters constantly, may lead to different EPS amounts and in some cases to different EPS types. In our case, we selected, isolated and purified from 34 LAB strains different samples. These strains were tested on three different culture medium compositions in order to select LAB strains that are highly EPS producers. From these 34 LAB strains we selected five in order to be subjected to the fermentative process in static and dynamic conditions, at 33°C for 48 hours. At the end of the fermentative process, the samples were subjected to enzyme inactivation (at 100 °C for 15 minutes) in order to stop the LAB strains growth and the enzymes actions on the EPS structure, avoiding the enzymatic degradations of the EPZ biosynthesized in culture mediums [1]. After the inactivation, EPS were extracted and purified following a protocol established according to the literature [2-5]. Due to the distinctive physico-chemical characteristics, one representative LAB strain (PP15) was presented in detail. The amount of purified EPS produced by this strain was evaluated by gravimetric measurement. The molecular weight and polydispersity index were determined by gel permeation chromatography (GPC). Thermal properties of the EPS samples were established by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The supramolecular structures of EPS have been identified by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (1H-NMR) spectroscopies. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS – UEFISCDI, project number PN-II-RU-TE-2014-4-0558. References [1] K.W. Lee, J.Y. Park, H.R. Jeong, H.J. Heo, N.S. Han, J.H. Kim, Anaerobe 2012, 18, 96-102. [2] C.T. Liu, F.J. Chu, C.C. Chou, R.C. Yu, Mutation Research 2011, 721, 157–162. [3] A. Tayuan, G.W. Tannock, S. Rodtong, African J. Microbiol. Research 2011, 5(22), 3693-3701. [4] R. Bennama, M. Fernandez, V. Ladero, M.A. Alvarez, N. Rechidi-Sidhoum, A. Bensoltane, Eur. Food Res. Technol. 2012, 234, 119–125. [5] S. Palomba, S. Cavella, E. Torrieri, A. Piccolo, P. Mazzei, G. Blaiotta, V. Ventorino, O. Pepe, Appl.Environ. Microbiol. 2012, 78(8), 2737-2747.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 19. MACROPOROUS SEMI-IPN COMPOSITE HYDROGELS BASED ON POLY(N,NDIMETHYLAMINOETHYL METHACRYLATE) AND STARCH 1“Petru

Diana Felicia Loghin*, Ecaterina Stela Drăgan Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, 700487 Iasi, Romania *E-mail: [email protected] Dedicated to the 150th anniversary of the Romanian Academy

Considerable interest has been focused last years on the smart hydrogels due to the numerous applications in controlled delivery of drugs and proteins and separation processes of small ionic species [1,2]. These gels can change their volume and/or shape in response to of the external stimuli, such as pH, temperature, ionic strength, solvent composition, electric or magnetic field, etc. The biocompatibility and biodegradability of these gels can be improved with biopolymers like polysaccharides, as components of the gel architecture [3.4]. Novel macroporous semi-interpenetrating polymer network (semi-IPN) composite hydrogels based on potato starch (PS) or anionically modified PS (PA) as polymers entrapped in a matrix of poly(N,Ndimethylaminoethyl methacrylate) (PDMAEM), prepared by ice-templating strategy, will be presented. The semi-IPN composite cryogels have been characterized by scanning electron microscopy and by swelling behavior as a function of the polysaccharides nature . The influence of the polysaccharides content and nature (PS or PA) on the response of the composite cryogels at various stimuli was thoroughly investigated (Figure 1). 25 PDMAEM5.10.PA1 PDMAEM5.10.PA1.5 PDMAEM5.15.PA1

20 15

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Figure 1. Equilibrium swelling ratio (SReq) as a function of temperature (left) and pH (right) for some composite cryogels prepared with PA as entrapped polymer. The potential of thus prepared composite cryogels for controlled delivery of drugs was also investigated. Acknowledgements This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCSIS – UEFISCDI, project number PN-II-ID-PCE-2011-3-0300. References [1] S. Hajizadeh, H. Kirsebom, I. Y. Galaev, B. Mattiasson, J. Separation Sci. 2010, 33, 1752-1759. [2] E. S. Dragan, Chem. Eng. J. 2014, 243, 572-590. [4] E. S. Dragan, M. M. Perju, M. V. Dinu, Carbohydr. Polym. 2012, 88, 270-281. [5] E. S. Dragan, D. F. Apopei, Chem. Eng. J. 2011, 178, 252-263.

Book of abstracts OC 20. AGGREGATION OF SOME HYDROPHOBICALLY MODIFIED POLYACRYLATES IN AQUEOUS SOLUTION Adriana Băran*, Ludmila Aricov, Dan-Florin Anghel Colloid Chemistry Laboratory, “Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, Post Office 12, P.O. Box 194, 060021 Bucharest, Romania *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy Water-soluble associative polymers (APs) are a class of compounds with hydrophilic backbone decorated with a few hydrophobic groups. In water, above a threshold concentration, the hydrophobic moieties undergo association and APs show peculiar properties such as spectacular increase of viscosity, gelation, drag reduction, and elasticity. They result from the reversible association of labels, and make APs distinguishable from regular polymers without associative groups. As a result, APs triggered applications in many fields for instance, personal care products, cosmetic, carriers for protein, DNA and drugs, waterborne paints, wastewater purification, enhanced oil recovery, etc. We are interested in these polymers because the specific behavior of hydrophobically modified sodium polyacrylates (NaPACn) is given by the interplay between the electrostatic repulsions of the carboxylate groups and the attractions of the hydrophobic grafts. In aqueous solution, the hydrophobic groups try to avoid the contact with water, and form intra- and intermacromolecular aggregates. Strong associations are obtained by increasing the alkyl chain length, because the modified polymers are less soluble in water. In this study, we are interested to find out new information on the behavior of randomly modified polyacrylates with linear C10 – C18 alkyl chains, by means of viscometry, steady-state fluorescence and refractometry. It is found out that each NaPAC n has a characteristic overlapping concentration (c* - demonstrated by viscometry), which lowers as the grafted chain is more hydrophobic. Above c*, the viscosity deviates from that of sodium polyacrylate (NaPA) and solutions of high viscosity are obtained. Steady-state fluorescence unveils intra-coil hydrophobic microdomains, whereas refractive index reveals the existence of both intra- and inter-coil aggregates. The complementarity and agreement between results obtained by different methods is presented Figure 1, together with a schematic representation of intra- and inter-coil aggregates.

I1/I3 RI Viscosity

c*

-5

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Figure 1. The complementarities between the methods, together with a schematic representation of intraand intercoil aggregates. Acknowledgements The research for this paper has been carried out within the Functional Complex Colloids Program of the “Ilie Murgulescu” Institute of Physical Chemistry, financed by the Romanian Academy. The authors gratefully acknowledge the support of the EU (ERDF) and Romanian Government allowing for acquisition of research infrastructure under POS-CCE O 2.2.1 project INFRANANOCHEM, No. 19/01.03.2009. This work is also supported by the PN-II-ID-PCE-2011-3-0916 Exploratory Research Project.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 OC 21. WATER-IN-OIL MICROEMULSIONS OF DIESEL AND DIESEL-RAPESEED OIL AS ALTERNATIVE FUELS. PHASE BEHAVIOR, INTERFACIAL TENSION, SOLUBILIZATION AND STRUCTURAL INVESTIGATIONS Marieta Balcan, Florentina-Cristina Mihăilescu, Monica Elisabeta Maxim, Ioana Catalina Gifu, Dan-Florin Anghel* Colloid Chemistry Laboratory, ‘Ilie Murgulescu’ Institute of Physical Chemistry, Romanian Academy, Spl. Independentei, No. 202, 060021, Bucharest, Romania E-mail: [email protected]; [email protected]

Dedicated to the 150th anniversary of the Romanian Academy The study presents the results on water-in-oil (w/o) fuel microemulsions (FME) containing diesel and/or diesel-rapeseed oil (RO) mixtures and water with or without electrolyte. The amphiphiles used to prepare the FME were eco-friendly namely: the nonionic surfactants Brij 30 (B30), Igepal CO-520 (NPEO5) and Tween 65 (T65), the anionic surfactant Synperonic A9C (Na) (SA9C), and the cosurfactant i-butanol (B). The water solubilization capacity in FME was studied by using pseudo-ternary phase diagrams. The one phase area for single nonionic surfactants follows the order: B30 > NPEO 5 > T65. It increases for mixtures of nonionic-anionic surfactant-cosurfactant, which allowed up to 10% wt. water solubilization without phase separation. In the presence of electrolyte (sodium acetate, AcNa) the one phase area decreases with the electrolyte concentration. In order to find the optimal formulation of the systems, properties such as the phase behavior, oil/water interfacial tension (σow), solubilization of oil and water (SPo and SPw) and structure of ME have been investigated for the Winsor (W)I ↔ WIII ↔WII system sequences with the electrolyte concentration. In the WIII systems, σ ow is minimal, whereas SPo, SPw and the droplet size are maximal. In all the investigated systems including those of WIV type, the particle size was in the microemulsion domain (below 100 nm). The results aim to provide useful information in successfully formulation and preservation of such ME as alternative fuels for diesel engines. Acknowledgements The research for this paper has been carried out within the Functional Complex Colloids Program of the ‘Ilie Murgulescu’ Institute of Physical Chemistry, financed by the Romanian Academy. The authors gratefully acknowledge the support of the EU (ERDF) and Romanian Government allowing for acquisition of research infrastructure under POS-CCE O 2.2.1 project INFRANANOCHEM, No. 19/01.03.2009. This work is also supported by the PN-II-ID-PCE-2011-3-0916 Exploratory Research Project.

Book of abstracts OC 22. BIOINSPIRED POLYTHIOPHENE-BASED POLYMERS IN HAIRY-ROD ARCHITECTURE: INFLUENCE OF GRAFTS LENGTH AND GRAFTING DENSITY ON THEIR ELECTRO AND BIOACTIVITY Anca-Dana Bendrea*, Luminita Cianga, Ioan Cianga “Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487, Iasi, ROMANIA *E-mail: [email protected]

Dedicated to the 150th anniversary of the Romanian Academy The “complex simplicity” of Nature was always a model for chemists and materials scientists. Thus, shapes, properties and building strategies of biological macromolecules were followed for a plethora of synthetic analogues able of mimicking biological systems. The self-assembly (SA), a fundamental theme in Nature, is a key concept in “bottom-up” hierarchically organized structures and a powerful alternative to nanofabrication approaches. In this context and following our previous research interest in the polythiophene field, the present communication reports on new engineered rod-coil amphiphilic structures, in “hairy-rod” architecture, in which the complex attractive and repulsive interactions required for SA were already encoded in the basic units (Figure 1). By usefully combining the electroactivity and photophysical properties of oligo/polythiophene main chains with biocompatibility and water solubility of polyethylene glycol (PEG) side chains, using 2,5- dibrominated thiophene-containing macromonomers (M1 and M2) as versatile building “bricks”, various macromolecular structures were designed and synthesized. Due to peculiar architecture, side chains grafting density and side chains length are molecular parameters influencing morphology and physical properties. Carefully selecting polymers’ synthesis methods we succeeded to modify these parameters in a controlled manner, giving rise to freedom in properties tunability for a specific envisioned applications (tissue engineering [1,4], cell imaging [2,3]). OCH3 n O O Br S

OCH3 n 2 S Pd(PPh3)4

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Figure 1. The synthesis routes for the bioinspired polythiophene compounds A lower grafting density of poly(ethylene glycol) (PEG) side chains on a polythiophene main chain resulted in an improved electroactivity and electrostability[1,5].The influence of both parameters on cell viability[2,3] as well as on cellular adhesion and proliferation [1,4] and on electro-biocompatibility [1,5] of polymeric substrates was also demonstrated. References [1] S. Maione, G. Fabregat, L. J. del Valle, A.-D. Bendrea, L. Cianga, I. Cianga, F. Estrany, C. Aleman, J. Polym. Sci. B Polym. Phys. 2015, 53, 239-252. [2] L. Cianga, A.-D. Bendrea, N. Fifere, L. E. Nita, F. Doroftei, D. Ag, M. Seleci, S. Timur, I.Cianga, RSC Adv. 2014, 4, 56385–56405. [3] A.-D.Bendrea, L. Cianga, E.G. Hitruc, I. Titorencu, I. Cianga, Mat. Plastice. 2013, 50, 71-78. [4] A.-D. Bendrea, G. Fabregat, J. Torras, S. Maione, L. Cianga, Luis J. del Valle, I. Cianga, C. Aleman, J. Mater.Chem. B. 2013, 33, 4135-4145. [5] A.-D. Bendrea, G.Fabregat, L. Cianga, F. Estrany, Luis J. del Valle, I. Cianga, C. Aleman, Polym. Chem. 2013, 9, 2709-2723.

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12th International Conference on Colloid and Surface Chemistry, ICCSC’2016 P1. WHEAT SEEDS AS MARKERS OF HEAVY METAL POLLUTION AND DECONTAMINATION OF TARNIŢA MINING AREA Alina Elena Butnariu1*, Raluca Stefănescu2, Olga Pintilie3, Manuela Murariu4, Ion Bunia4, Andriana Surleva5, Cătălina Ionica Ciobanu2, Carmen Iacoban6, and Maria Magdalena Zamfirache1 of Biology, “Al. I. Cuza” University, 11 Carol I, Iasi-700506, Romania of Chemistry, “Al. I. Cuza” University, 11 Carol I, Iasi-700506, Romania 3 Faculty of Geography and Geology, “Al. I. Cuza” University, 11 Carol I, Iasi-700506, Romania 4Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, Iasi-700487, Romania 5University of Chemical Technology and Metallurgy, Analytical Chemistry Department, Sofia, Bulgaria 6Forest Research and Management Institute, Research Station C-lung Moldovenesc Suceava, Romania *E-mail address: [email protected] 1Faculty

2Faculty

As a result of mining the metalliferous ores, metal pollution has become one of the most serious environmental problems in Tarnita area today [1]. The sterile dumps and soil around the closed barite mine of Tarnita, Suceava region, contain increased amounts of heavy metals such as copper, iron, lead and zinc, as well as arsenic. The seeds of wheat (Triticum aestivum L.) were used as indicator of toxicity for both sterile material and contaminated soils, since the metal-rich mining waste from Tarnita mine site have a negative effect on seed and seedling metabolism, which results in wheat week germination, growth inhibition, photosynthesis impairment, low water uptake and nitrate assimilation. In our experiments, heavy metal contaminated materials were ultrasonic extracted with water in the ratio 1 g : 10 mL for at least 15 min, followed by centrifugation at 5000 rpm to obtain the clear supernatant. Lots of 50 wheat seeds were treated with 5 mL of toxic supernatant for 1 h, then let to germinate on double filter paper in 9-cm Petri dishes. Separately, the toxic metals concentrated in the supernatant was subjected to the sodium hydroxide-based precipitation. The resulted clear solution was neutralized with nitric acid solution and used in germination experiments or percolated through ion exchange resins. All these hydroxide-based or resin-treated decontaminated solutions were used in the biological investigations as well. The content of pollutants of all solutions was measured by ICP-OES or AAS. Since the contaminants were removed either by precipitation or ion exchange, the germination rate as well as the growth of the resulted plantlets increased significantly. Heavy metal accumulation in plant tissues resulted in the inhibition of most physiological processes [2]. Metals may penetrate the plants by absorption from soil solutions or by deposition of dust pollutants from the air, on the aerial parts of the plants. Some metabolic pathways leading to precipitation of heavy metals as metal sulfides, phosphates or carbonates are related to possible biotechnology application [3]. Acknowledgements Authors acknowledge to Partnership Project Metafore (Contract 107/2014) for financial support. References [1] D. Stumbea, Environ. Eng. Manag. J. 2010, 9, 1045-1051. [2] B.J. Alloway, Environ. Pollut. 2013, 22, 3-9. [3] P. Kotrba, T. Ruml, Czech. Chem. Communic. 2000, 65, 1205-1247.

Book of abstracts P2. PARTICULATE MATTER AND GASEOUS POLLUTANTS VARIABILITY IN IASI URBAN AREA, NORTH-EASTERN ROMANIA Alina-Giorgiana Galon (Negru)1, Romeo Iulian Olariu1,2, Cecilia Arsene1,2* 1”Alexandru

Ioan Cuza” University of Iasi, Faculty of Chemistry, Department of Chemistry, 11 Carol I, 700506 Iasi, Romania 2”Alexandru Ioan Cuza” University of Iasi, Integrated Center of Environmental Science Studies in the North Eastern Region - CERNESIM, 11 Carol I, 700506 Iasi, Romania *E-mail: [email protected]

Urban air pollution represents one of the greatest environmental problems facing humanity even nowadays [1]. The most important air pollutants causing adverse effects on human health and environment include particulate matter (PM), ozone (O3), sulfur dioxide (SO2), nitrogen oxides (NOx=NO+NO2), carbon monoxide (CO), volatile organic compounds (VOCs) and heavy metals [2-3]. There is suggestion that increases in mortality and hospital admissions due to respiratory and cardiovascular diseases might be highly associated with air pollutants exposure [4]. Gaseous atmospheric species such as HNO 3 (originated from NOx) and H2SO4 (derived from gas phase oxidation of SO 2) are the most important precursors of nitrate and sulfate aerosols, comprising a significant fraction of the ambient air PM2.5 mass concentration [5]. Sunlight induced photochemical reactions of NO x and VOCs precursor gases represent an important pathway of the ground level O3 formation [6]. In the north-eastern Romania, Iasi region, reports on the variability of the previously mentioned air pollutants are very scarce. Information about the atmospheric burden of particulate matter and gaseous pollutants from the ambient air in Iasi urban area are reported in the present work. Ambient particulate matter samples were collected over a time period of 36-hour on aluminum filters using a 13 stages cascade Dekati Low-Pressure Impactor (DLPI) (0.0276-9.94 µm size range and 29.85 L min-1 flow rate). Simultaneously, samples have been collected on polycarbonate hydrophilic membranes (of 8.0 and 0.4 µm) and quartz filters appropriately disposed on a Stacked Filter Unit (SFU). For PM fractions the mass concentration has been gravimetrically determined. Gaseous pollutants like O 3, CO, CO2, NOx and SO2 were measured using Ecotech analyzers. The meteorological data (temperature, relative humidity (RH), solar radiation, wind speed) were provided by a Weather Hawk GSM-240 station. Data analysis revealed that PM2.5 (particles of diameter