Problems with the gelling of emulsified colloidal silica

• Autorzy: Hayrapetyan S. S. , Khachatryan H. G.
• Języki publikacji: EN

Abstrakty

EN

Important aspects of the rapid gelling of the stabilized silica sols used to produce silica gel have been studied. Rapid gelling is necessary when producing micro-spherical silica gels from stabilized silica sols, because silica sol emulsions are not stable for long periods of time. The effect on rapid gel formation of potassium silicate, added to the silica sol before emulsification, has been studied and the possibility of efficient control of these processes has been investigated. It has been shown that it is possible to control the gelling of silica sol by adding potassium silicate, which not only secures rapid gelling of emulsified silica sols but also ensures introduction of active silica to the silica hydrogel, which reinfor-ces the structure of the gel obtained. The effect of exchange of intermicellar water in micro-spherical silica hydrogels, by acetic acid, acetone, and ethanol, on the sorption volu-me of micro-spherical silica gels obtained from stabilized silica sols has been investigated. The use of stabilized silica sols as initial raw material ensures constancy of specific surface area and pore volume, because these primarily depend on the properties of the colloidal particles and their size distribution. Data characterizing the pore structure of the silica gels reveal that exchange of intermicellar water by other liquids of lower surface tension affects the pore volume only.

• Wydawca: University of Silesia in Katowice ; Akademiai Kiado
• Czasopismo: Acta Chromatographica
• Rocznik: 2004
• Tom: No. 14
• Strony: 49--59
• Opis fizyczny: Bibliogr. 8 poz., rys., tab.

Twórcy

autor

Hayrapetyan S. S.

• Yerevan State University, 1 Alek Manoukian St, 375025 Yerevan-25, Republic of Armenia

autor

Khachatryan H. G.

• Yerevan State University, 1 Alek Manoukian St, 375025 Yerevan-25, Republic of Armenia

Bibliografia

• [1] R.E. Mayors, Analytical HPLC Column Technology. The Current Status, LC–GC Int., April 1998, pp. 7–21
• [2] R.E. Mayors, New Chromatography Columns and Accessories at the 1997 Pittsburg Conference. Part I, LC–GC Int., April 1997, pp. 220–239
• [3] J.W. Dolan, Column Packing – What’s at the Bottom of it? LC–GC Int., May 1998, pp. 292–297
• [4] Agilent Technologies, Catalogue, 2000, p. 30
• [5] R.K. Iler, The Chemistry of Silica, Part 2, Wiley, New York, 1976
• [6] US Patent No. 4,059,658, International Classification Index CO 4B 35/14, 1977
• [7] US Patent No. 4,554,211, International Classification Index CO 1B 33/16, 1986
• [8] US Patent No. 3,374,180, International Classification Index CO 1B 33/16, 1965