Lauric Acid Mediated Phase Transformation and Surface ...

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2012

Supporting Materials for Lauric Acid Triggered in-situ Surface Modification and Phase Selectivity of Calcium Carbonate: Its Application as an Oil Sorbent

Arpita Sarkar, Amit K. Ghosh and Samiran Mahapatra* Unilever R&D, 64 Main Road, Whitefield, Bangalore 560066, India.

C-7

Ca-O stretching 1112 cm -1

Transmittance

Ca-Laurate

Na-Laurate

1104 cm-1

Lauric Acid

1123 cm-1 1900

1700

1500

1300

1100

900

700

Wave number (cm-1)

Figure S-1. FT IR spectra of Lauric acid, Na-Laurate, Ca-Laurate and Sample C-7, CaCO3 synthesized in the presence of Lauric acid.

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Electronic Supplementary Material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2012

105

(a)

100

95

8%

(b)

90 85 80 75 44%

42%

70 65

60 55 50 45 40 50

150

250

350

450

550

650

750

850

Figure S-2. a) TGA curve of Calcite sample synthesized in the absence of any additive (C-1) , and (b) TGA profile of CaCO3 synthesized in the presence of Lauric acid (C-6, Ca2+:Lauric acid 1:0.05)

Table S-3. Percentage Weight Loss different CaCO3 samples at 250-600oC

C-1

Ca2+: Lauric acid (mole ratio) 1:0

Wt. Loss at 250600oC(%) Nil

C-6

1 : 0.05

8

C-7

1 : 0.1

15

Sample

Θ = 26o

Figure S-4. Contact angle formed b y a drop of sunflower oil on a substrate coated with sample C-5 (Ca2+: Lauric acid mole ratio 1:0.01)

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Electronic Supplementary Material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2012

Table S-5. Oil absorption efficiency of various hydrophobic CaCO3 samples from oil-water mixture (1:10)* Ca2+ : Lauric acid (mole ratio)

Wt. of water recovered (g)

Oil absorption efficiency (%)

C-2

1: 0.001

17

85

C-4

1:0.0075

19

95

C-6

1:0.05

19.7

98.5

Sample

*Total volume of oil-water mixture was 20ml. 2g CaCO3 samples were added in each case.

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