A structural approach towards understanding the aqueous corrosion of alkali aluminoborate glasses Saurabh Kapoor,1 Randall E. Youngman,2 Kiryl Zakharchuk,3 Aleksey Yaremchenko,3 Nicholas J. Smith,2 Ashutosh Goel,1,1 1
Department of Materials Science and Engineering, Rutgers, The State University of New Jersey,
Piscataway, NJ, 08854, USA 2
Science and Technology Division, Corning Incorporated, Painted Post, NY, 14870, USA
3
CICECO – Aveiro Institute of Materials, Department of Materials and Ceramic Engineering,
University of Aveiro, 3810-193 Aveiro, Portugal
Corresponding author Email:
[email protected]; Ph: +1-848-445-4512 1
1
Abstract Despite an ongoing strenuous effort to understand the compositional and structural drivers controlling the chemical durability of oxide glasses, there is still no complete consensus on the basic mechanism of glass dissolution that applies to a wide composition space. One major reason for this problem is the structural complexity contained within the multicomponent silicate glasses chosen for glass corrosion studies. The non-silicate network polyhedra present in these glasses interact with one another, often in unpredictable ways, by forming a variety of structural associations, for example, Al[IV] – B[III], B[III] – B[IV], resulting in significant influence on both the structure of the glass network and related macroscopic properties. Likewise, the formation of a variety of next-neighbor linkages, as well as increasingly complex interactions involving Si and differently coordinated next-nearest neighbor cations are very difficult to decipher experimentally. Consideration of these factors motivates instead a different strategy: that is, the study of a sequence of SiO2 – free ternary or quaternary glass compositions, whose structures can be unambiguously determined and robustly linked to their corrosion properties. With this aim, the present study is focused on understanding the structural drivers governing the kinetics and mechanism of corrosion of ternary Na2O–Al2O3–B2O3 glasses (in water) over a broad composition space comprising glasses with distinct structural features. It has been shown that the addition of Al2O3 to binary sodium borate glasses decreases their corrosion rate in water, and converts their dissolution behavior from congruent to incongruent leading to formation of six coordinated alumina, and higher concentration of four coordinated boron (in comparison to pre-dissolution glasses) in postdissolution glass samples. The drivers controlling the corrosion kinetics and mechanism in these glasses based on their underlying structure have been elucidated. Some open questions have been proposed which require an extensive analysis of surface chemistry of pre- and post-dissolution samples and will be investigated in our future work. 2
1.
Introduction Silicate glasses are known to possess chemical durability superior to most other glass
families, which is evident from the survival of medieval window and natural glasses (e.g., obsidians and Libyan Desert glass) for thousands or even millions of years.1 For this reason, and in addition to its many other beneficial properties, multicomponent silicate glasses form the backbone of glass industry and are used in a majority of the technological and functional applications. This includes, for example, architecture, and automotive industry, pharmaceutical and electronic packaging, laboratory and kitchenware, etc.2-5 However, despite their high chemical durability, silicate glasses gradually dissolve and corrode when exposed to aqueous solutions, where their dissolution kinetics are a function of several thermo-chemical parameters such as glass chemistry, solution chemistry, reaction temperature, time and pH.6, 7 An in-depth understanding of the fundamental science governing the glass corrosion will allow us to design glass compositions with predictable degradation rates—behavior which can be utilized to help with critically needed advancements in, for example, immobilization of radioactive waste in glasses, or design of third generation bio-resorbable glasses for tissue engineering.8, 9 These potential benefits to mankind have led to decades of research effort focused on understanding the compositional and structural drivers controlling the mechanism and kinetics of silicate glass corrosion. The evolution has been driven by an idea that the understanding of relationships between chemical composition of glasses and their structure at an atomistic level will not only help in unearthing the fundamental mechanisms of glass corrosion, but will also enable the development of models to predict material functions and properties from first principles.10, 11 Despite an ongoing strenuous effort in this direction, there is still no complete consensus on the basic mechanism of glass dissolution that applies to a wide composition space. One major reason for this problem is the structural complexity contained within the multicomponent silicate 3
glasses chosen for glass corrosion studies (for example, ISG 12, 13). While these compositions are relevant for their specific applications, they are commonly comprised of multiple network former species, for example, SiO2, B2O3, Al2O3 and P2O5, and other non-framework cations. The nonsilicate network polyhedra present in these glasses interact with one another, often in unpredictable ways, by forming a variety of structural associations (including but not limited to Al [IV] – B[III], B[III] – B[IV], AlO5, AlPO4, and BPO4 units),14-19 resulting in significant influence on both the structure of the glass network and related macroscopic properties. Likewise, the formation of a variety of next-neighbor linkages (e.g. Si–O–Al, Si–O–B, Si–O–P and Si–O–Al–O–B linkages), as well as increasingly complex interactions involving Si and differently coordinated next-nearest neighbor cations (e.g. Si-O-P[n] where n can be a range of values denoting connectivity to the glass network), are very difficult to even experimentally measure and decipher using techniques such as
29
Si,
27
Al,
11
B or
31
P magic angle spinning – nuclear magnetic resonance (MAS-NMR)
spectroscopy, much less connect structure to corrosion properties. Although attempts have been made to understand these interactions in silicate glasses using 17O triple quantum (3Q) MAS-NMR spectroscopy,20-22 models pertaining to these structural details are still under-developed. With complex multicomponent silicate glass systems, results are typically reported in the form of “composition–property relationships” through the development of empirical models,23-25 but wherein their chemical and structural complexity complicates understanding of the fundamental material science governing these relationships. This hinders the evolution from empirical models based on “composition–property relationships” to more robust quantitative/predictive models based on “composition–structure–property relationships”.26 Consideration of these factors motivates instead a different strategy: that is, the study of a sequence of simpler ternary glass compositions, whose structures can be unambiguously determined and robustly linked to corrosion
4
properties. One example is SiO2-free oxide glasses (for example, borates, phosphates), which provides us an opportunity to obtain deeper and clearer insight into the interactions between nonsilicate framework units and non-framework cations in the glass structure,14, 17, 27-29 and their impact on the macroscopic glass properties.30-35 This fundamental knowledge, when extended to more complex silicate glasses, will not only allow us to understand the drivers of glass dissolution based on underlying glass structure, but will also form the baseline for development of nonempirical models to predict the chemical durability of multicomponent oxide glasses. The present study is focused on understanding the dissolution mechanism and kinetics of corrosion of glasses in the Na2O-Al2O3-B2O3 ternary system. The focus on borate glasses is justified considering the fact that combination of borate glasses with SiO2 results in the formation of borosilicate glasses – one of the most important glass systems from scientific, technological and commercial viewpoints.13, 36, 37 In fact, it has been shown that most structural features in alkali borosilicates are similar to those of alkali borates.37 It is therefore important to understand the structure–property relationships in borate-based glass compositions before extending them to more complex borosilicates, or aluminoborosilicates.38-40 Borate glasses are also fascinating in that they do not behave as might be expected when compared to most well-studied silicate glass systems, as is evident from equations 1-3.41 In silicates, ≡Si–O–Si≡ + A2O = ≡Si–O-A+ + A+-O–Si≡ (creation of non-bridging oxygen, NBO) (1)
In borates – Scenario 1, ½A2O + BØ3 = A+ + BOØ2- (creation of NBO, as in silicates)
(2)
In borates – Scenario 2, ½A2O + BØ3 = A+ + BØ4- (conversion of BIII to BIV)
(3)
where, A2O refers to an alkali oxide, and Ø represents bridging oxygen atoms that are shared between adjacent borate units. The further choice to focus on the sodium aluminoborate system has been made to enable glass compositions with a rich variety of structural features over a broader composition space and glass forming range – for example, glasses can be designed with different 5
Al[IV]/Al[V] ratios. From a technological viewpoint, borate glasses have been historically confined to the realms of academic research due to their relatively poor chemical durability, with limited gains in our understanding of the fundamental science governing the chemical durability of these glasses in the intervening years. This assertion is supported by the minimal number of research articles published on this topic (on binary and ternary borates) in the last five decades (excluding research articles investigating the in vitro/in vivo bioactivity of borate glasses).42-46 However, with the advent of multicomponent borate glasses for functional applications in human biomedicine,47-52 waste management,53, 54 and cover glass applications,55 the need for greater understanding about the structural drivers governing the chemical durability of these glasses has become increasingly important. With the aforementioned perspective, the work presented in this paper is focused on understanding the dissolution behavior and early-stage release kinetics of sodium aluminoborate glasses designed over a broad composition space covering per-alkaline (Na/Al>1), metaaluminous (Na/Al = 1) and per-aluminous (Na/Al 1) at low Al2O3 content. With increasing Al2O3 concentration, the fraction of 5- and 6-coordinated aluminum increases monotonically, with the highest concentration of AlO5 units (~23%) being detected in the peraluminous ([Na2O]/[Al2O3] 8), Al(OH)4- (aq) is formed. Therefore, the suppressed release of Al2O3 from the glasses in this study is likely attributed to this pH effect, where the observed pH change is influenced primarily—
21
and in a competing sense—by the release of boron and sodium from the glasses. The release of boron is tantamount to additions of boric acid in solution, and has the effect of decreasing solution pH, whereas Na release will show an opposite effect on the pH of the leachate solution. The increase in pH with increasing Al2O3 in the Series 1 glasses is therefore likely attributed to a relative decrease in the boron concentration in the bulk glass compositions, reducing the amount of boron being released from the glasses into DI water to buffer the release of alkali. Turning to the Series 2 glasses, the final pH of the solution is observed to increase systematically as a function of Na concentration in the glasses (Inset: Figure 8b).75 Analogous to the pH trends, the change in chemical dissolution rates of Na, Al and B from glasses are positively correlated to the Na2O content in the glasses. However, based on the structural description of these glasses as investigated using MAS-NMR and Raman spectroscopy, it is highly likely that different structural descriptors may be influencing the rate of glass dissolution depending upon their [Na2O]/[B2O3] ratio as explained below. In the case of per-alkaline glasses with Na2O/B2O3 < 1, the decrease in chemical durability with increasing Na2O is intriguing, and its structural origin is likely attributable to several competing effects. First, there is a relative increase in N4 fraction in this regime, from ~9% up to a peak of ~23%—all things being equal, this trend might be expected to increase the connectivity of the network and its corresponding durability, as has been observed in bulk borate glasses 44, 46. However, in this case the increasing N4 fraction with Na2O concentration is effectively offset by the overall reduction in B2O3 content in the glass composition (from 65mol% down to 45mol%), such that the absolute BIV fraction of the network increases only slightly in this portion of the composition walk. Meanwhile, Na+ BO4– bonds can be readily attacked by hydronium ions to facilitate ion exchange, leading to a proportional increase in pH along the walk as more Na and
22
less B is liberated into solution. It can be concluded that the increasing dissolution rate across this series up to the N4 maximum (Na/B 0.7 agrees with the study of Zuchner et al.,15 where it has been shown that the presence of Al3+ facilitates the formation of NBOs as the AlO4 sites in the framework interact more favorably with the asymmetric BO3 in comparison to the BO4 at [Na2O]/[B2O3] > 0.7. The formation of these NBO-bearing structural units decreases the overall connectivity of the network, leading to an intuitive increase in dissolution rate proportional to NBO concentration likewise observed in other systems.82 The NMR results suggests that hydrolysis of bridging oxygen atoms around Al atoms at the glass water interface is accompanied by a change in the coordination number of the Al atom since the structure of the glass consists of primarily tetrahedral Al. The formation of 6-fold coordinated aluminum on the leached surface of an aluminosilicate glass was first reported by
23
Tsomaia et al.83 An observed increase in coordination of aluminum is a result of breakage of bridging oxygen (BO) by molecular water which then forces the Al3+ to go into high coordination to charge balance.83 It is worth noting that Criscenti et al.84 had hypothesized the formation of AlV units as an intermediate step during the conversion of AlIV to AlVI units in aluminosilicate glass corrosion. However, neither experimental results of Criscenti et al.84 nor the results obtained in this study exhibit the formation of any AlV units as an intermediate step during glass dissolution. Given that, the bulk structure of the pre-dissolution glasses was primarily dominated by 4coordinated aluminum, its conversion to octahedral coordination post-dissolution may occur through two different mechanisms. The first possibility is the structural re-arrangement in the aluminoborate glass network due to leaching of alkali ions charge compensating the tetrahedral aluminum, thus resulting in a highly ordered 6-coodinated aluminate network. On the other hand, the second possibility is the precipitation of octahedral aluminum on or within the surface layer during the residual rate regime of glass corrosion. While in the first scenario, the concentration of 6-coordinatred alumina rich phases in post-dissolution samples should be dictated by the Al2O3 concentration in the glass compositions, the XRD results of post-dissolution samples do not support this hypothesis. The qualitative crystalline phase fraction (based on the peak intensity of phase reflections) in post-dissolution glass samples demonstrates a positive correlation with their dissolution rates (Figure 9, S5 and S6), implying the possibility of precipitation mechanism being in play in this study. It should be noted here that according to a previous study by Tsomaia et. al.,83 the formation of high coordinated Al in post dissolution aluminosilicate glass sample is not due to precipitation but due to the transformation of the glass network (mineral lattice) during leaching. Therefore, a detailed analysis of pre- and post- dissolution glass samples using surface sensitive characterization techniques, for example, X-ray photoelectron spectroscopy (XPS), time of flight
24
– secondary ion mas spectroscopy (TOF – SIMS), Rutherford backscattering, energy recoil detection analysis (ERDA), and 27Al{1H} cross-polarization MAS-NMR is required to validate the proposed hypothesis. The 11B MAS-NMR of the post-dissolution glass samples does not exhibit any sharp peaks signifying crystalline species, thus negating the possibility of formation of boron-containing crystalline phases. An increase in boron coordination in glass upon interaction with water may be explained on the basis of a two-step mechanism, as shown in Figure 11. A similar mechanism has been recently proposed by Garofalini et al.85 to explain the interaction between water and boron at the surface of soda-lime aluminoborosilicate glasses using molecular dynamic simulations. However, this hypothesis leads to the formation of BIV – BIV linkages in the hydrated glass structure, which is unlikely due to tetrahedral avoidance rule.27 Interestingly, in two separate studies – one by Zapol et al.86, and another by Geneste et al.87 – where aqueous corrosion of sodium borosilicate glasses has been studied using first principles, it has been shown that the fraction of tetrahedral boron decreases upon interaction with water, where tetrahedral B bonded with a Si or another B breaks and forms a trigonal planar BIII unit and a neutral silanol (Si–OH) or boranol (B– OH) group. This is not in agreement with our experimental observations. Another question that warrants further structural investigation on the post-dissolution glass samples is: which cation is charge-compensating N4 units in post-dissolution samples? Given that Na+ preferentially charge compensates AlIV over BIV (as per our common understanding), while all the aluminum in the postdissolution sample is in 6-coordination, is the increased concentration of N4 units in postdissolution glass samples being charge compensated by H+ ions? Interestingly, recent study by Kim et. al.,
54
have postulated the possibility of H+ ion behaving as a charge compensator based
on elemental mapping. However, its verification requires further investigations. Hence, our future
25
studies will focus on finding answers to these questions using a suite of surface sensitive and bulk characterization techniques.
5. Conclusions The present study gives an insight over a broad compositional regime to enhance our understanding of the
composition-structure-chemical durability relationship in
alkali
aluminoborate glasses. The dissolution behavior of aluminoborate glasses in the present investigation is independent form their ionic mobility of cations but are highly influenced by [Na2O]/[Al2O3] and [Na2O–Al2O3]/[B2O3] ratios. The addition of Al2O3 changes the dissolution behavior of the binary alkali-borate from congruent to incongruent. Aluminum shows minimal tendency to leach out of the glass structure and forms high-coordinated Al-containing crystalline phases post-dissolution. In addition, the qualitative crystalline phase fraction in post-dissolution glass samples demonstrate a positive correlation with their respective dissolution rates. Furthermore, with increase in dissolution time, we observed an increase in the fraction of tetrahedral boron along with a noticeable change in the BIII resonance where dissolution of glass leads to decrease in the fraction of BIII non-ring structures in the glass after immersion. The present investigation puts forth open questions about the coordination change observed in case of Al and B post dissolution, which will form the basis of our next study
Acknowledgements This material is based upon work supported by Corning Incorporated and National Science Foundation (under Grant No. 1507131). K.Z. and A.Y. would like to acknowledge financial support by the FCT, Portugal (project IF/01072/2013/CP1162/CT0001 and project CICECO Aveiro Institute of Materials POCI-01-0145-FEDER-007679 (FCT ref. UID/CTM/50011/2013), 26
financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement). Conflict of Interest The authors declare no competing conflict of interest. Supporting Information Available The Supporting Information is available Reference 1. Henderson, J. Ancient glass: an interdisciplinary exploration. Cambridge University Press: 2013. 2. Lampert, C. M. Large-area smart glass and integrated photovoltaics. Sol. Energy Mater. Sol. Cells 2003, 76 (4), 489-499. 3. Burrows, K.; Fthenakis, V. Glass needs for a growing photovoltaics industry. Sol. Energy Mater. Sol. Cells 2015, 132, 455-459. 4. Iacocca, R. G.; Toltl, N.; Allgeier, M.; Bustard, B.; Dong, X.; Foubert, M.; Hofer, J.; Peoples, S.; Shelbourn, T. Factors affecting the chemical durability of glass used in the pharmaceutical industry. AAPS PharmSciTech 2010, 11 (3), 1340-1349. 5. Mauro, J. C.; Philip, C. S.; Vaughn, D. J.; Pambianchi, M. S. Glass Science in the United States: current status and future directions. Int. J. Appl. Glass Sci. 2014, 5 (1), 2-15. 6. Paul, A. Chemical durability of glass. In Chemistry of Glasses, Paul, A., Ed. Springer Netherlands: Dordrecht, 1982; pp 108-147. 7. Kapoor, S.; Goel, A.; Tilocca, A.; Dhuna, V.; Bhatia, G.; Dhuna, K.; Ferreira, J. M. F. Role of glass structure in defining the chemical dissolution behavior, bioactivity and antioxidant properties of zinc and strontium co-doped alkali-free phosphosilicate glasses. Acta Biomater. 2014, 10 (7), 3264-3278. 8. Hench, L. L.; Polak, J. M. Third-generation biomedical materials. Science 2002, 295 (5557), 10141017. 9. Donald, I. W.; Metcalfe, B. L.; Taylor, R. N. J. The immobilization of high level radioactive wastes using ceramics and glasses. J. Mater. Sci. 1997, 32 (22), 5851-5887. 10. Tilocca, A. Models of structure, dynamics and reactivity of bioglasses: a review. J. Mater. Chem. 2010, 20 (33), 6848-6858. 11. Aertsens, M.; Ghaleb, D. New techniques for modelling glass dissolution. J. Nuc. Mater. 2001, 298 (1-2), 37-46. 12. Gin, S.; Abdelouas, A.; Criscenti, L. J.; Ebert, W. L.; Ferrand, K.; Geisler, T.; Harrison, M. T.; Inagaki, Y.; Mitsui, S.; Mueller, K. T.; Marra, J. C.; Pantano, C. G.; Pierce, E. M.; Ryan, J. V.; Schofield, J. M.; Steefel, C. I.; Vienna, J. D. An international initiative on long-term behavior of high-level nuclear waste glass. Mater. Today 2013, 16 (6), 243-248. 13. Vienna, J. D.; Ryan, J. V.; Gin, S.; Inagaki, Y. Current understanding and remaining challenges in modeling long-term degradation of borosilicate nuclear waste glasses. Int. J. Appl. Glass Sci. 2013, 4 (4), 283-294. 14. van Wüllen, L.; Züchner, L.; Müller-Warmuth, W.; Eckert, H. 11B{27Al} and 27Al{11B} double resonance experiments on a glassy sodium aluminoborate. Solid State Nucl. Magn. Reson. 1996, 6 (3), 203212.
27
15. Zuchner, L.; Chan, J. C. C.; Muller-Warmuth, W.; Eckert, H. Short-range order and site connectivities in sodium aluminoborate glasses: I. Quantification of local environments by high-resolution B-11, Na-23, and Al-27 solid-state NMR. J. Phys. Chem. B 1998, 102 (23), 4495-4506. 16. Chan, J. C. C.; Bertmer, M.; Eckert, H. Double-quantum cross-polarization between half-integer quadrupolar spin systems: 11B↔23Na and 11B↔27Al. Chem. Phys. Lett. 1998, 292 (1–2), 154-160. 17. Chan, J. C. C.; Bertmer, M.; Eckert, H. Site connectivities in amorphous materials studied by double-resonance NMR of quadrupolar nuclei: High-resolution 11B ↔27Al spectroscopy of aluminoborate glasses. J. Am. Chem. Soc. 1999, 121 (22), 5238-5248. 18. Munoz, F.; Montagne, L.; Delevoye, L. Influence of phosphorus speciation on the phase separation of Na2O-B2O3-SiO2 glasses. Phys. Chem. Glasses 2008, 49 (6), 339-345. 19. Kapoor, S.; Guo, X.; Youngman, R. E.; Hogue C. L.; Mauro, J. C.; Rzoska, S. J.; Bockowski, M.; Jensen, L. R.; Smedskjaer, M. M. Network glasses under pressure: permanent densification in modifierfree Al2O3−B2O3−P2O5−SiO2 systems. Phy. Rev. Appl. 2017, 7 (5), 054011 20. Angeli, F.; Delaye, J. M.; Charpentier, T.; Petit, J. C.; Ghaleb, D.; Faucon, P. Investigation of Al–O–Si bond angle in glass by 27Al 3Q-MAS NMR and molecular dynamics. Chem. Phys. Lett. 2000, 320 (5–6), 681-687. 21. Gambuzzi, E.; Pedone, A.; Menziani, M. C.; Angeli, F.; Caurant, D.; Charpentier, T. Probing silicon and aluminium chemical environments in silicate and aluminosilicate glasses by solid state NMR spectroscopy and accurate first-principles calculations. Geochim. Cosmochim. Acta 2014, 125, 170-185. 22. Du, L. S.; Stebbins, J. F. Network connectivity in aluminoborosilicate glasses: A high-resolution 11 B, 27Al and 17O NMR study. J. Non-Cryst. Solids 2005, 351 (43–45), 3508-3520. 23. Strachan, D. M.; Croak, T. L. Compositional effects on long-term dissolution of borosilicate glass. J. Non-Cryst. Solids 2000, 272 (1), 22-33. 24. Strachan, D. M., Glass dissolution: testing and modeling for long-term behavior. J. Nuc. Mater. 2001, 298 (1–2), 69-77. 25. Matyás, J.; Huckleberry, A.; Rodriguez, C. A.; Vienna, J. D.; Kruger, A. A. Empirical model for formulation of crystal-tolerant hlw glasses. In Advances in Materials Science for Environmental and Energy Technologies, John Wiley & Sons, Inc.: 2012; pp 121-126. 26. Mauro, J. C.; Tandia, A.; Vargheese, K. D.; Mauro, Y. H. Z.; Smedskjaer, M. M., Accelerating the design of functional glasses through modeling. Chem. Mater. 2016, 28 (12), 4267-4277. 27. Du, L. S.; Stebbins, J. F. Site connectivities in sodium aluminoborate glasses: multinuclear and multiple quantum NMR results. Solid State Nucl. Magn. Res. 2005, 27 (1–2), 37-49. 28. Janssen, M.; Eckert, H. 11B{23Na} Rotational echo double resonance NMR: a new approach for studying the spatial cation distribution in sodium borate glasses. Solid State Ionics 2000, 136, 1007-1014. 29. Zeyer-Düsterer, M.; Montagne, L.; Palavit, G.; Jäger, C. Combined 17O NMR and 11B–31P double resonance NMR studies of sodium borophosphate glasses. Solid State Nucl. Magn. Res. 2005, 27 (1), 5064. 30. Eckert, H. Network former mixing (NFM) effects in ion-conducting glasses - structure/property correlations studied by modern solid-state NMR techniques. Diffusion Foundations 2016, 6, 144-193. 31. Larink, D.; Eckert, H.; Reichert, M.; Martin, S. W. Mixed Network Former Effect in IonConducting Alkali Borophosphate Glasses: Structure/Property Correlations in the System M 2O(1/3) [(B2O3)x(P2O5)(1-x)](2/3) (M = Li, K, Cs). J. Phys. Chem. C 2012, 116 (50), 26162-26176. 32. Christensen, R.; Byer, J.; Olson, G.; Martin, S. W., The densities of mixed glass former 0.35 Na2O + 0.65 [xB2O3 + (1 − x)P2O5] glasses related to the atomic fractions and volumes of short range structures. Journal of Non-Crystalline Solids 2012, 358 (3), 583-589. 33. Christensen, R.; Byer, J.; Olson, G.; Martin, S. W. The glass transition temperature of mixed glass former 0.35Na2O + 0.65[xB2O3 + (1 − x)P2O5] glasses. J. Non-Cryst. Solids 2012, 358 (4), 826-831. 34. Christensen, R.; Olson, G.; Martin, S. W. Ionic conductivity of mixed glass former 0.35Na2O + 0.65[xB2O3 + (1 – x)P2O5] glasses. J. Phys. Chem. B 2013, 117 (51), 16577-16586. 35. Hidi, I. J.; Melinte, G.; Stefan, R.; Bindea, M.; Baia, L. The study of the structure and bioactivity of the B2O3•Na2O•P2O5 system. J. Raman Spectrosc. 2013, 44 (8), 1187-1194.
28
36. Smedskjaer, M. M.; Youngman, R. E.; Mauro, J. C. Principles of Pyrex® glass chemistry: structureproperty relationships. Appl. Phys. A 2014, 116 (2), 491-504. 37. Hubert, M.; Faber, A. J. On the structural role of boron in borosilicate glasses. Phys. Chem. Glasses 2014, 55 (3), 136-158. 38. Pierce, E. M.; Rodriguez, E. A.; Calligan, L. J.; Shaw, W. J.; Pete McGrail, B. An experimental study of the dissolution rates of simulated aluminoborosilicate waste glasses as a function of pH and temperature under dilute conditions. Appl. Geochem. 2008, 23 (9), 2559-2573. 39. Pierce, E. M.; Reed, L. R.; Shaw, W. J.; McGrail, B. P.; Icenhower, J. P.; Windisch, C. F.; Cordova, E. A.; Broady, J., Experimental determination of the effect of the ratio of B/Al on glass dissolution along the nepheline (NaAlSiO4)–malinkoite (NaBSiO4) join. Geochim. Cosmochim. Acta 2010, 74 (9), 2634-2654. 40. Kerisit, S.; Pierce, E. M. Monte Carlo simulations of the dissolution of borosilicate and aluminoborosilicate glasses in dilute aqueous solutions. Geochim. Cosmochim. Acta 2011, 75 (18), 52965309. 41. Varshneya, A., K. Fundamentals of Inorganic Glasses, Second Edition. Society of Glass Technology, UK: 2013. 42. Adams, P. B.; Evans, D. L. Chemical durability of borate glasses. In Borate Glasses, Pye, L. D.; Fréchette, V. D.; Kreidl, N. J., Eds. Springer US: 1978; Vol. 12, pp 525-537. 43. Das, C. R. The reaction between borate glass and attacking agents—Part III: Equilibrium pH of the alkali borate glasses and their relationship with chemical durability and the glass composition. Tran. Indian Ceram. Soc. 1967, 26 (1), 155-158. 44. Velez, M. H.; Tuller, H. L.; Uhlmann, D. R. Chemical durability of lithium borate glasses. J. NonCryst. Solids 1982, 49 (1–3), 351 - 362. 45. Bengisu, M.; Brow, R. K.; Yimaz, E.; Mogus-Milankovic, A.; Reis, S. T. Aluminoborate and aluminoboro silicate glasses with high chemical durability and the effect Of P2O5 additions on the properties. J. Non-Cryst. Solids 2006, 352 (32-35), 3668-3676. 46. George, J. L.; Brow, R. K. In-situ characterization of borate glass dissolution kinetics by mu-Raman spectroscopy. J. Non-Cryst. Solids 2015, 426, 116-124. 47. Lepry, W. C.; Nazhat, S. N. Highly Bioactive sol-gel-derived borate glasses. Chem. Mater. 2015, 27 (13), 4821-4831. 48. Lin, Y. N.; Brown, R. F.; Jung, S. B.; Day, D. E. Angiogenic effects of borate glass microfibers in a rodent model. J. Biomed. Mater. Res. Part A 2014, 102 (12), 4491-4499. 49. Deliormanli, A. M.; Liu, X.; Rahaman, M. N. Evaluation of borate bioactive glass scaffolds with different pore sizes in a rat subcutaneous implantation model. J. Biomater. Appl. 2014, 28 (5), 643-653. 50. Lopes, P. P.; Leite Ferreira, B. J. M.; Gomes, P. S.; Correia, R. N.; Fernandes, M. H.; Fernandes, M. H. V. Silicate and borate glasses as composite fillers: a bioactivity and biocompatibility study. J. Mater. Sci. Mater. Med. 2011, 22 (6), 1501-1510. 51. Rahaman, M. N.; Day, D. E.; Bal, B. S.; Fu, Q.; Jung, S. B.; Bonewald, L. F.; Tomsia, A. P. Bioactive glass in tissue engineering. Acta Biomater. 2011, 7 (6), 2355-2373. 52. Liang, W.; Rahaman, M. N.; Day, D. E.; Marion, N. W.; Riley, G. C.; Mao, J. J. Bioactive borate glass scaffold for bone tissue engineering. J. Non-Cryst. Solids 2008, 354 (15-16), 1690-1696. 53. Erdogan, C.; Bengisu, M.; Erenturk, S. A. Chemical durability and structural analysis of PbO-B2O3 glasses and testing for simulated radioactive wastes. J. Nucl. Mater. 2014, 445 (1-3), 154-164. 54. Kim, M.; Corkhill, C. L.; Hyatt, N. C.; Heo, J. Development, characterization and dissolution behavior of calcium-aluminoborate glass wasteforms to immobilize rare-earth oxides. Sci. Rep. 2018, 8. 55. Januchta, K.; Youngman, R. E.; Goel, A.; Bauchy, M.; Rzoska, S. J.; Bockowski, M.; Smedskjaer, M. M. Structural origin of high crack resistance in sodium aluminoborate glasses. J. Non-Crys. Solids 2017, 460, 54-65. 56. Tournié, A.; Majérus, O.; Lefèvre, G.; Rager, M. N.; Walmé, S.; Caurant, D.; Barboux, P. Impact of boron complexation by Tris buffer on the initial dissolution rate of borosilicate glasses. J. Colloid Interface Sci. 2013, 400, 161-167.
29
57. Mazurin, O.; Streltsina, M.; Shvaiko-Shvaikovskaya, T., Sci Glass 6.5 (Glass Property Information System). Institute of Theoretical Chemistry, Shrewsbury, MA, USA 2005. 58. Massiot, D.; Fayon, F.; Capron, M.; King, I.; Le Calvé, S.; Alonso, B.; Durand, J. O.; Bujoli, B.; Gan, Z.; Hoatson, G. Modelling one‐and two‐dimensional solid‐state NMR spectra. Magn. Reson. Chem. 2002, 40 (1), 70-76. 59. Massiot, D.; Bessada, C.; Coutures, J.; Taulelle, F. A quantitative study of 27Al MAS NMR in crystalline YAG. J. Magn. Reson. 1990, 90 (2), 231-242. 60. Shelby, J. E., Introduction to glass science and technology. Royal Society of Chemistry: 2005. 61. Morin, E. I.; Stebbins, J. F. Separating the effects of composition and fictive temperature on Al and B coordination in Ca, La, Y aluminosilicate, aluminoborosilicate and aluminoborate glasses. J. Non-Cryst. Solids 2016, 432, 384-392. 62. Bunker, B. C.; Kirkpatrick, R. J.; Brow, R. K.; Turner, G. L.; Nelson, C. Local-structure of alkaline-earth boroaluminate crystals and glasses: II, 11B and 27Al MAS NMR spectroscopy of alkalineearth boroaluminate glasses. . J. Am. Ceram. Soc. 1991, 74 (6), 1430-1438. 63. El Hayek, R.; Ferey, F.; Florian, P.; Pisch, A.; Neuville, D. R. Structure and properties of lime alumino-borate glasses. Chem. Geol. 2017, 461, 75-81. 64. Bechgaard, T. K.; Goel, A.; Youngman, R. E.; Mauro, J. C.; Rzoska, S. J.; Bockowski, M.; Jensen, L. R.; Smedskjaer, M. M. Structure and mechanical properties of compressed sodium aluminosilicate glasses: Role of non-bridging oxygens. J. Non-Cryst. Solids 2016, 441, 49-57. 65. MacKenzie, K.; M. E. S., Multinuclear Solid-State NMR of Inorganic Materials. Pergamon: Amsterdam, 2002. 66. Yun, Y. H.; Bray, P. J. 11B nuclear magnetic resonance studies of Li2O-B2O3 glasses of high Li2O content. J. Non-Cryst. Solids 1981, 44 (2), 227-237. 67. Stebbins, J. F. Cation sites in mixed-alkali oxide glasses: correlations of NMR chemical shift data with site size and bond distance. Solid State Ionics 1998, 112 (1-2), 137-141. 68. Tagg, S.; Youngman, R.; Zwanziger, J. The structure of sodium tellurite glasses: sodium cation environments from sodium-23 NMR. J. Phys. Chem. 1995, 99 (14), 5111-5116. 69. Kamitsos, E. I.; Karakassides, M. A.; Chryssikos, G. D. Vibrational spectra of magnesium-sodiumborate glasses. 2. Raman and mid-infrared investigation of the network structure. J. Phys. Chem. 1987, 91 (5), 1073-1079. 70. Meera, B. N.; Ramakrishna, J. Raman spectral studies of borate glasses. J. Non-Cryst. Solids 1993, 159 (1-2), 1-21. 71. Brow, R. K.; Tallant, D. R.; Turner, G. L. Polyhedral arrangements in lanthanum aluminoborate classes. J. Amer. Ceram. Soc. 1997, 80 (5), 1239-1244. 72. Konijnendijk, W L; Stevels, J. M., The structure of borate glasses studied by Raman scattering. J. Non-Cryst. Solids 1975, 18 (3), 307-331. 73. Ebert, W. L. Comparison of the results of short-term static tests and single-pass flow-through tests with LRM glass (ANL-06/51); Argonne National Laboratory: Argonne, IL, USA, 2006. 74. Ebert, W. L.; Bates, J. K., A comparison of glass reaction at high and low glass-surface solution volume. Nucl. Tech. 1993, 104 (3), 372-384. 75. Stone-Weiss, N.; Pierce, E. M.; Youngman, R. E.; Gulbiten, O.; Smith, N. J.; Du, J.; Goel, A. Understanding the structural drivers governing glass – water interactions in borosilicate glasses: Toward a unified approach to study the chemical dissolution behavior of bioactive glasses. Acta Biomater. 2017, 65, 436-449. 76. Zhang, Z.; Hirao, K.; Soga, N. Water corrosion behavior of densified glass. II. Borate glasses. J. Non-Cryst. Solids 1991, 135 (1), 62-66. 77. Hamilton, J. P.; Pantano, C. G. Effects of glass structure on the corrosion behavior of sodiumaluminosilicate glasses. J. Non-Cryst. Solids 1997, 222 (0), 167-174. 78. Januchta, K.; Youngman, R. E.; Goel, A.; Bauchy, M.; Logunov, S. L.; Rzoska, S. J.; Bockowski, M.; Jensen, L. R.; Smedskjaer, M. M. Discovery of ultra-crack-resistant oxide glasses with adaptive networks. Chem. Mater. 2017, 29 (14), 5865-5876.
30
79. Bunker, B. C. Molecular mechanisms for corrosion of silica and silicate-glasses. J. Non-Cryst. Solids 1994, 179, 300-308. 80. Wesolowski, D. J.; Palmer, D. A. Aluminum speciation and equilibria in aqueous solution: V. Gibbsite solubility at 50°C and pH 3–9 in 0.1 molal NaCl solutions (a general model for aluminum speciation; analytical methods). Geochim. Cosmochim. Acta 1994, 58 (14), 2947-2969. 81. Bunker, B. C.; Arnold, G. W.; Day, D. E.; Bray, P. The effect of molecular structure on borosilicate glass leaching. J. Non-Cryst. Solids 1986, 87 (1), 226-253. 82. Lowry, J. D., Dissolution behavior of alkali borate glasses. University of Missouri - Rolla, Rolla, MO, 2002. 83. Tsomaia, N.; Brantley, S. L.; Hamilton, J. P.; Pantano, C. G., NMR evidence for formation of octahedral and tetrahedral Al and repolymerization of the Si network during dissolution of aluminosilicate glass and crystal. Am. Miner. 2003, 88 (1), 54-67. 84. Criscenti, L. J.; Brantley, S. L.; Mueller, K. T.; Tsomaia, N.; Kubicki, J. D., Theoretical and 27Al CPMAS NMR investigation of aluminum coordination changes during aluminosilicate dissolution. Geochim. Cosmochim. Acta 2005, 69 (9), 2205-2220. 85. Garofalini, S. H.; Ha, M. T.; Urraca, J. Simulations of the surfaces of soda lime aluminoborosilicate glasses exposed to water. J. Amer. Ceram. Soc. 2017, 101, 1135-1148. 86. Zapol, P.; He, H.; Kwon, K. D.; Criscenti, L. J. First-principles study of hydrolysis reaction barriers in a sodium borosilicate glass. Int. Appl. Glass Sci. 2013, 4 (4), 395-407. 87. Geneste, G.; Bouyer, F.; Gin, S. Hydrogen–sodium interdiffusion in borosilicate glasses investigated from first principles. J. Non-Cryst. Solids 2006, 352 (28), 3147-3152.
31
Tables
Table 1. Analysed glass compositions (mol.%), density and molar volume (VM) Glass ID Analysed Density Series I Na2O Al2O3 B2O3 g cm-3 AB-0 20.25 0.00 79.75 2.177 AB-5 20.43 5.38 74.18 2.160 AB-10 20.15 10.48 69.37 2.151 AB-15 20.00 15.34 64.66 2.158 AB-20 19.63 20.68 59.69 2.186 AB-25 19.76 25.69 54.55 2.241 Series II NB-15 15.01 20.47 64.52 2.177 NB-25 25.36 20.60 54.04 2.234 NB-30 30.11 20.19 49.70 2.299 NB-35 34.95 20.23 44.82 2.349 NB-40 39.68 20.43 39.89 2.363 NB-45 44.91 20.38 34.71 2.379 NB-50 49.51 20.61 29.88 2.399
32
VM cm3 31.28 32.27 33.15 33.81 34.10 34.00 34.42 33.21 32.10 31.25 30.90 30.54 30.13
Table 2. Fraction of boron and aluminum species for glasses obtained by deconvolution of
27
Al
and 11B MAS NMR spectra. The uncertainties in intensity (Int) and isotropic chemical shift (δCS) are estimated to be ±2% and ±1 ppm respectively. Glass AB-0 AB-5 AB-10 AB-15 AB-20 AB-25 NB-15 NB-25 NB-30 NB-35 NB-40 NB-45 NB-50
AlIV Int (%) δCS (ppm) … … 97.9 58.67 95.2 58.72 90.1 58.73 81.3 59.18 73.5 59.72 56.5 58.04 96.5 60.47 98.0 61.78 98.2 63.35 98.1 64.63 98.2 66.4 98.9 68.35
AlV Int (%) δCS (ppm) … … 2.1 30.54 4.8 30.77 9.7 31.49 17.6 32.1 23.2 32.56 35.1 32.28 3.5 32.11 2.0 31.88 1.8 32.84 1.9 35.05 1.8 38.2 1.1 38.93
33
AlVI Int (%) δCS (ppm) … … … … … 0.2 5.75 1.1 5.7 3.3 6.18 8.4 4.97 … … … … … … … … … … … …
N3 (%) 70.5 75.8 81.5 86.4 90.0 92.0 90.6 86.9 80.6 77.2 81.4 87.7 96.0
N4 (%) 29.5 24.2 18.5 13.6 10.0 8.0 9.4 13.1 19.4 22.8 18.6 12.3 4.0
Table 3. Normalized loss (g/m2) as a function of time (h) for investigated glass samples. Time (h)
Na
0.25 0.5 1 3 6 12 24 Time (h) 0.25 0.5 1 3 6 12 24 Time (h) 0.25 0.5 1 3 6 12 24 Time (h) 0.25 0.5 1 3 6 12 24 Time (h) 0.25 0.5 1 3 6 12 24 Time (h) 0.25 0.5 1 3 6 12 24
33.28 70.54 169.60 265.18 276.31 224.29 266.83 10.07 26.40 59.91 169.74 194.58 170.77 194.26 10.32 18.67 56.75 147.88 176.20 199.25 188.18 5.27 14.29 39.02 131.55 180.47 202.47 203.14 -7.21 24.04 85.87 132.06 182.56 208.42 1.43 5.56 15.13 43.08 81.55 98.51 260.44
Series 1 B AB-0 32.57 73.68 164.92 258.02 260.90 226.98 261.31 AB-5 10.47 27.53 59.59 189.81 203.22 172.33 199.81 AB-10 11.45 17.95 56.15 137.82 173.40 195.03 180.80 AB-15 6.02 13.22 36.19 113.32 163.18 196.09 198.41 AB-20 3.99 6.10 21.25 72.02 112.59 163.45 193.52 AB-25 1.96 4.37 13.40 35.39 71.67 93.87 237.28
Al
Na
-
0.98 3.23 11.60 68.41 137.80 150.47 168.10
3.48 1.17 27.49 73.11 74.41 37.59 23.83
5.76 20.30 36.86 97.11 120.49 150.24 201.72
4.78 6.04 15.74 34.08 35.12 26.27 16.57
5.86 17.65 43.36 150.97 188.81 204.03 205.20
-2.54 5.90 19.67 24.08 21.41 15.16
9.05 32.60 67.32 167.91 175.36 186.07 190.24
-1.72 4.82 12.48 17.10 20.09 16.35
31.00 54.86 115.66 167.73 154.17 180.63 180.59
0.36 1.54 3.84 6.43 9.82 9.94 12.71
52.01 73.10 145.39 181.20 172.38 188.24 180.53
34
Series 2 B NB-15 1.26 3.38 10.68 63.91 125.59 139.75 181.17 NB-25 5.25 17.57 30.35 88.82 108.61 141.70 203.93 NB-30 6.32 14.92 35.19 116.29 158.55 195.27 201.38 NB-35 8.57 26.53 52.55 132.52 152.96 171.68 179.88 NB-40 29.37 43.97 96.91 148.85 145.49 170.75 172.48 NB-45 47.05 69.45 136.38 175.43 165.73 180.36 176.67
Al 0.19 0.61 2.11 7.50 11.65 10.54 10.54 0.98 2.95 4.79 12.89 14.89 19.33 15.88 1.92 3.93 9.71 33.73 40.21 38.03 29.34 3.98 8.63 17.60 48.64 44.85 42.62 36.48 13.02 21.71 47.16 65.23 55.15 57.43 45.05 35.71 49.55 95.18 99.30 86.50 85.36 64.91
Figures
Figure 1. Ternary diagram of the investigated glasses, overlaying target and measured compositions, as well as glass-forming range.
35
(a)
AlIV
(b)
IV
Al
AlVI
NB-50 V
Al
AB-25
NB-45
AB-20
NB-40 NB-35
AB-15
NB-30 AB-10
AlIV
NB-25 AlV
AB-5
120 100 80 27
60
40
20
0
-20 120 100 80 27
Al NMR shift (ppm)
60
40
20
Al NMR shift (ppm)
Figure 2. 27Al MAS-NMR spectra of a) Series 1 (b) Series 2
36
VI
Al
0
NB-15
-20
(b)
(a)
BIII
BIII
BIV
BIV
AB-25
NB-50
AB-20
NB-45
AB-15
NB-40 NB-35
AB-10 NB-30 AB-5
NB-25
AB-0
30 25 20 15 10 11
5
0
NB-15
-5 -10 30 25 20 15 10 11
B NMR shift (ppm)
5
B NMR shift (ppm)
Figure 3. 11B MAS-NMR spectra of (a) Series 1 (b) Series 2
37
0
-5 -10
(a)
20
AB-0 AB-5 AB-10 AB-15 AB-20 AB-25
10
0 23
-10
-20
-30
(b)
-40 40
NB-15 NB-25 NB-30 NB-35 NB-40 NB-45 NB-50
20
0
-20
23
-40
Na NMR shift (ppm)
Na NMR shift (ppm)
Figure 4. 23Na MAS-NMR spectra of (a) Series 1 (b) Series 2
38
-60
(a)
III
II
I
IV
Intensity (a.u)
AB-25 AB-20 AB-15 AB-10
AB-5 AB-0
200
400
600
800 1000 1200 1400 1600
Raman shift (cm-1) (b)
I
III
II
IV NB-50
Intensity (a.u)
NB-45 NB-40 NB-35 NB-30 NB-25 NB-15
200 400 600 800 1000 1200 1400 1600
Raman shift (cm-1) Figure 5. Raman spectra of the investigated glasses (a) Series1 (b) Series 2
39
(a) 300
(b)
200 150
NL (g/m2)
NL (g/m2)
250 200
Na Al B
100
150 100
Na B
50
50 0
0 0
5
10 15 20 25
Time (h)
0
5
10 15 20 25
Time (h)
Figure 6. Normalized loss of glasses with [Al2O3]/[B2O3] (series 1) as a function of immersion time in deionized water (up to 24 hours) at 65 ºC (a) AB-0, (b) AB-15, Each data point represents the average of two replicated experiments.
40
(a) 200 NL (g/m2)
16
Rate (g/m2.h)
160 120
y = 18.389x - 3.3566 R² = 0.9988
12 8 4 0 0
80
0.5
1
1.5
Time (h) Na B Al
40 0 0
5
10
15
20
25
[Al2O3] (mol%) (b)
9.0 8.8 8.6 8.2 AB-0 AB-5 AB-10 AB-15 AB-20 AB-25
8.0 7.8 7.6 7.4
9.0 8.9 pH
pH
8.4
8.8 8.7 0
7.2 0
5
10
15
5
10 15 20 [Al2O3] (mol%)
20
25
25
Time (h) Figure 7. (a) Dissolution rate of Boron and Sodium as a function [Al2O3] concentration in series 1 of glasses (INSET: Normalized loss (Na) of glass AB-25 as a function of immersion time in deionized water (up to 1 h), fitted linearly to determine initial dissolution rate of B. Each data point represents the average of two replicated experiments.) and (b) pH values of the leachate solution in Series 1 of glasses in DI water at 65 ºC (Inset: variation of pH after 24 h with change in [Na2O]/[B2O3] ratio).
41
140
Na B Al
Rate (g/m2.h)
120 100 80 60 40 20 0 0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Na2O/B2O3
(b) 10.5 10.0 9.5 8.5 10.4
8.0
NB-15 NB-25 NB-30 NB-35 NB-40 NB-45
7.5 7.0 6.5
10.0
pH
pH
9.0
9.6 9.2 8.8 8.4 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Na2O/B2O3
6.0 0
5
10
15
20
25
Time (h) Figure 8. Dissolution rate of Sodium, Boron, and Aluminum as a function [Na2O]/[B2O3] concentration in series 2 of glasses (Each data point represents the average of two replicated experiments). (b) pH values of the leachate solution in Series 2 of glasses in DI water at 65 ºC (Inset: variation of pH after 24 h with change in [Na2O]/[B2O3] ratio).
42
(a) 24h
Intensity (a.u)
12h 6h 3h 1h Boehmite Bayerite
10
20
30
40
50
60
70
80
90
2q (degrees)
(b)
Intensity (a.u)
24h 12h 6h 3h 1h
Boehmite Bayerite
10
20
30
40
50
60
70
80
90
2q (degrees) Figure 9. X-ray diffractograms of glass powders after immersion for varying time up to 24 h for (a) AB-20 and (b) NB-45
43
(a) 24h
6h
before dissolution
100
80
60
40
20
0
-20
-40
27
Al NMR shift (ppm)
(b)
N4= 16
24h
N4= 12
6h before dissolution
N4= 9
30
25
20 11
15
10
5
0
-5
-10
B NMR shift (ppm)
Figure 10. Post dissolution MAS-NMR spectra of AB-20 glass (a) 27Al (b) 11B MAS-NMR spectra
44
Figure 11. Two-step reaction mechanism explaining the increase in boron coordination from BIII to BIV in glass upon interaction with water. The modifiers has been removed from the image for simplicity.
45
Table of content graphic
46
