Chemistry, Physics and Technology of Surface, 2016, 7 (1), 12-19.

Quantum chemical simulation of surface hydrophobization of silicate materials with alkali siliconates



DOI: https://doi.org/10.15407/hftp07.01.012

A. G. Grebenyuk, D. B. Nasiedkin, Yu. V. Plyuto

Abstract


The method of density functional theory was used to study the interaction between methylsilicate CH3Si(OH)2O– or phenylsilicate C6H5Si(OH)2O– anions and silica surface. The probability of these processes was estimated on the basis of analysis of the calculated energy characteristics. The reactions of formation of both methylsilicic and phenylsilicic aсids from their anions in the presence of carbon dioxide for binding hydroxide ions as hydrocarbonate ones are promoted by anion hydration (the energy effects are –61 and –46 kJ/mol respectively). The condensation of methylsilicic acid with silanol groups of silica surface is more effective than that of phenylsilicic one (the energy effects are –36 and –26 kJ/mol respectively).

Keywords


silicate materials; hydrophobization; alkali siliconates; carbon dioxide; quantum chemical simulation

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References


1. Lyons A. Silicons, Silanes and Siloxanes. In: Construction Materials Reference Book. 2nd Edition. (D. Doran, B. Cather, eds., Routledge, 2013).

2. Fic S., Barnat-Hunek D. The effectiveness of hydrophobisation of porous building materials by using the polymers and nanopolymers solutions. Int. J. Mater. Sci. Eng. 2014. 2(2): 93. https://doi.org/10.12720/ijmse.2.2.93-98

3. Syed A., Donadio M. Silane sealers/hydrophobic impregnation – the European perspective. Concrete Repair Bulletin. (Sept./Oct. 2013): 12. http://www.icri.org/PUBLICATIONS/2013/PDFs/septoct13/CRBSeptOct13_Syed-Donadio.pdf

4. Kather W.S., Torkelson A. Sodium methylsiliconate – nature and applications. Ind. Eng. Chem. 1954. 46(2): 381. https://doi.org/10.1021/ie50530a049

5. Műller R., Meier G., Rotzsche H. Űber Silikone. LV. Kryoskopische Molgewichtsbestimmungen an Kalium- und Natriummethylsilikonat mit geschmolzenem Glaubersalz. J. Inorganic General Chem. 1962. 314(5–6): 291. https://doi.org/10.1002/zaac.19623140507

6. Okumoto S., Fujita N., Yamabe S. Theoretical study of hydrolysis and condensation of silicon alkoxides. J. Phys. Chem. A. 1998. 102(22): 3991. https://doi.org/10.1021/jp980705b

7. Kudo T., Gordon M.S. Theoretical studies of the mechanism for the hydrolysis of silsesquioxanes. 1. Hydrolysis and initial condensation. J. Am. Chem. Soc. 1998. 120(44): 11432. https://doi.org/10.1021/ja980943k

8. Uchino T., Sakka T., Ogata Y., Iwasaki M. Mechanism of hydration of sodium silicate glass in asteam environment: 29Si NMR and ab initio molecular orbital studies. J. Phys. Chem. 1992. 96(18): 7308. https://doi.org/10.1021/j100197a031

9. Demianenko E., Ilchenko M., Grebenyuk A., Lobanov V. A theoretical study on orthosilicic acid dissociation in water clusters. Chem. Phys. Lett. 2011. 515(4–6): 274. https://doi.org/10.1016/j.cplett.2011.09.038

10. Kravchenko A.A., Demianenko E.M., Grebenyuk A.G., Lobanov V.V. Quantum chemical simulation of silica surface protolytic equilibrium. Him. Fiz. Tehnol. Poverhni. 2014. 5(1): 16. [in Ukrainian].

11. Schmidt M.W., Baldridge K.K., Boatz J.A., Elbert S.T., Gordon M.S., Jensen J.H., Koseki S., Matsunaga N., Nguyen K.A., Su Sh., Windus T.L., Dupuis M., Montgomery J.A. General atomic and molecular electronic – structure system: Review. J. Comput. Chem. 1993. 14(11): 1347. https://doi.org/10.1002/jcc.540141112




DOI: https://doi.org/10.15407/hftp07.01.012

Copyright (©) 2016 A. G. Grebenyuk, D. B. Nasiedkin, Yu. V. Plyuto

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