Investigation of the systems silica and silica containing chromium in alcohol medium

The purpose of this work is to obtain micrometer sized spherical particles of silica and silica-chromium from sodium silicate. Spherical particles wer e prepared by sol-gel method from hydrolysis to polycondensation of aqueous sodium silicate in alcohol medium. Chromium was added to the system for so me samples. Compositions and morphologies were achieved by changing the pre cipitation agent. X-ray diffractometry, electrophoretic mobility, infrared spectroscopy and scanning electron microscopies were carried out on these p articles to identify phases, determine particle mobility, morphology, parti cle sizes, shapes and order at short distance. Non-crystalline silica parti cles with spherical shapes and micrometric size were obtained. The surface potentials of the silica particles differed from that of the silica-chromiu m particles. (C) 1999 Elsevier Science B.V. All rights reserved.