RESEARCH OF BUILDING MATERIALS

Diethyldichloro-, ethyltrichlorosilanes in reactionswith cement stone minerals

Vestnik MGSU 7/2013
  • Novosel’nov Anatoliy Aleksandrovich - Moscow State University of Civil Engineering (MGSU) Candidate of Technical Sciences, Associate Professor, Associate Professor, Department of General Chemistry, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Myasoedov Evgeniy Mikhaylovich - Moscow State University of Mechanical Engineering (MAMI); Moscow State University of Civil Engineering (MGSU) Candidate of Chemical Sciences, Associate Professor, Department of General and Analytical Chemistry, Moscow State University of Mechanical Engineering (MAMI); Professor, Department of General Chemistry, Moscow State University of Civil Engineering (MGSU), Moscow State University of Mechanical Engineering (MAMI); Moscow State University of Civil Engineering (MGSU), 38 Bol’shaya Semenovskaya str., Moscow, 107023, Russian Federation; 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Sidorov Vyacheslav Ivanovich - Moscow State University of Civil Engineering (MGSU) Doctor of Chemical Sciences, Professor, Professor, Department of General Chemistry, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 114-120

One of the uses of organosilicon compounds (OSCs) is associated with the production of hydrophobic coatings for building materials. Water-proofing properties of hydrophobic coatings extend the service life and improve the performance properties of building materials. Some of OSCs form hydrophobic polymer films on the surface of various building materials. High stability of these coatings is associated with the possible existence of chemical bonds between the polyorganosiloxane film and the hydrophilic surface of the material. Presently, there is no clear understanding of the mechanism of interaction between the mineral substrate and the film, although OSCs are widely used as part of water-proof building materials.Towards this end, the authors have identified the conditions that facilitate the formation of protective coatings on the surface of mineral substrates, if OSCs are applied to the surface of building materials. The authors have completed a research into the nature of interaction between the coatings and the mineral substrate to determine their physical and chemical properties. The silylation of calcium hydroxide by diethyldichloro-, ethyltrichlorosilanes was studied as the model process. The products of silylation were studied using methods of gas-liquid chromatography, infrared spectroscopy, electron mi- croscopy, X-ray diffraction and differential thermal analysis.The authors used the method of gas-liquid chromatography to discover that the periods of fast and slow conversion of silanes corresponded to the periods of domination of hydrolysis or hemosorbtion. The authors discovered that the hydrolysis products of diethyldichloro-, ethyltrichlorosilanes do not react with calcium hydroxide.The authors used the method of the thermal analysis to discover the physical and chemical properties of oligomers and polymers formed on the surface of the mineral substrate. Comparison of the findings of the thermal analysis of poliethylpolysiloxane in the mixture and in the block (312 °С) shows that there is practically no shift of the maximum exotherm. The following components of the hydrophobic effect of silylation where identified: formation of insoluble polyorganosiloxanes on the surface and inside the mineral stone accompanied by partial hemosorbtion, and physical adsorption of monomers, oligomers and polyorganosiloxanes - hydrolyzates on the mineral stone surface.

DOI: 10.22227/1997-0935.2013.7.114-120

References
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  4. Sidorov V.I., Novosel’nov A.A., Myasoedov E.M. Issledovanie sililirovaniya gidroksida kal’tsiya metiltrikhlorsilanom [Study of Silylation of Calcium Hydroxide by Methyltrihlorosilane]. Vestnik MGSU [Proceeding of Moscow State University of Civil Engineering]. Moscow, 2010, vol. 3, no. 4, pp. 133—139.
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New method for sol-gel synthesis of orthosilicates

Vestnik MGSU 10/2013
  • Malyavskiy Nikolay Ivanovich - Moscow State University of Civil Engineering (MGSU) Candidate of Chemical Sciences, Professor, Department of General Chemistry, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Zvereva Viktoriya Vladimirovna - Moscow State University of Civil Engineering (MGSU) student, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 140-146

Orthosilicates of bivalent metals are widely employed by various technologies, including the production of building materials. In the last decades, several sol-gel methods were proposed to obtain high-purity orthosilicates in a laboratory environment. The objective of this research was to prepare powdered crystalline orthosilicates of calcium, magnesium, zinc and cadmium using a new sol-gel technique that comprises a hydrogel combustion stage.APSTOL (3-aminopropylsilanetriol), a water-soluble silicone having low polymerizability and high stability at any ambience, was used as a silica precursor. Metal nitrates were used as metal oxide precursors, water was the solvent. Nitric acid was added to every precursor mixture to prevent precipitation of metal hydroxides. Solid hydrogels, capable of spontaneous combustion, were generated in the aftermath of the dry-out of the prepared solutions. Combustion products were studied using FTIR method (Fourier transform infrared spectroscopy) and TG-DSC methods (Thermogravimetric Analysis and Differential Scanning Calorimetry), and heated thereafter. Final products were also studied using Fourier transform infrared spectroscopy.It was found that all combustion products (except for the Cd-silicate system) were poorly crystallized orthosilicates in stable or meta-stable crystalline forms. Upon subsequent heating, well-crystallized orthosilicates (willemite, larnite and forsterite) were formed.As a result, the proposed synthesis procedure demonstrated its efficiency for the synthesis of powdered crystalline or semicrystalline orthosilicates and oxy-orthosilicates of bivalent metals. The main strengths of this procedure include its high synthesis rate and absolute stability of the precursor solutions.

DOI: 10.22227/1997-0935.2013.10.140-146

References
  1. Afonina G.A., Leonov V.G., Popova O.N. Poluchenie poroshka forsterita metodami zol'-gel' tekhnologii [Using Sol-gel Technology to Extract Powdered Forsterite]. Steklo I keramika [Glass and Ceramics]. 2005, no. 8, pp. 19—24.
  2. Negahdari Saberi Z., Alinejad B., Golestani-Fard F. Synthesis and Characterization of Nanocrystalline Forsterite through Citrate-nitrate Route. Ceram. Int. 2009, vol. 35, pp. 1705—1708.
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  6. Malyavskiy N.I., Pokid'ko B.V. Zol'-gel' sintez ortosilikatov [Sol-gel Synthesis of Orthsilicates]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2012, no. 8, pp. 131—138.
  7. El Nahhal I.M., Chehimi M.M., Cordier C., Dodin G. XPS, NMR and FTIR Structural Characterization of Polysiloxane-immobilized Amine Ligand System. J. Non-Cryst. Solids. 2000, no. 275, pp. 142—146.
  8. Sreekanth Chakradhar R.P., Naqabhushana B.M., Chandrappa G.T., Ramesh K.P., Rao J.L. Solution Combustion Derived Nanocrystalline Zn2SiO4: Mn Phosphors: a Spectroscopic View. J. Chem. Phys. 2004, vol. 121, pp. 10250—10259.
  9. Lukic S.R., Petrovic D.M., Dacanin L.J., Marinovic-Cincovic M., Antic Z., Krsmanovic R. Gel Combustion Synthesis of Transition Metal Ions Doped Zn2SiO4 Powder. J. Optoelectron. and Adv. Materials. 2008, vol. 10, pp. 2748—2752.
  10. Lazarev A.N. Kolebatel'nye spektry i stroenie silikatov [Vibrational Spectra and Structure of Silicates]. Leningrad, Nauka Publ., 1968, 348 p.
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