EFFECT OF CALCIUM, SODIUM AND CHLORIDE IONS ON THE GROWTH OF IMOGOLITE TUBES AS MEASUED BY GEL FORMING PROPERTY

Abstract

To examine the effect of coexisting salts on the yield and gel forming property of synthetic imogolite, neutralized solutions of Si (OH) ₄ and AlCl₃ with added NaCl and CaCl₂ were heated at 96°C. X-ray diffraction (XRD) on the freeze-dried products showed that the yield of imogolite decreased as the salt concentration increased. The gel volume determined by alkalinization and centrifugation of the heated sols approximately paralleled the intensity of imogolite peaks in XRD. The examination of the relationship between the ion concentrations and the gel volume showed that the gel forming property was solely determined by the chloride ion concentration and the accompanying cations had little effect under the present experimental conditions.