A study of cobaltous chloride dispersion on the surface of the silica gel

Cobalt II. salts dispersed on different substrates have functions as humidity indicating desiccants and catalysts. CoCl2 containing silica gel granules of 3 mm size for packed column applications were prepared by impregnation of the aqueous solution of the salt to silica hydro gel at pH near 2, drying and ageing methods. X-ray diffraction and electron microprobe studies indicated cobalt element was both dispersed in particulate form and as sub-monolayer. IR spectra indicated presence of Si–OH groups in all of the silica gels. CoCl2 containing silica gels changed colour from blue to pink upon moisture adsorption due to presence of the CoCl2, Co2SiO4and Na2CoSiO4. q1999 Elsevier Science B.V. All rights reserved.