抄録
Two kinds of silica sols prepared by different methods were used to investigate effects on properties of zeolite/silica sol deposits formed by the electrophoretic deposition (EPD). Hy type silica sol, prepared by hydrolysis of tetraethyl orthosilicate (TEOS) with NaOH aqueous solution, consisted of fine (<0.1 µm) and strongly agglomerative particles. These sol particles inhibited the EPD rate of this system and the silica sol content was limited up to 14.2 percent of the deposit. On the other hand, St type silica sol, prepared by hydrolysis of TEOS with NH3 aqueous solution (Stöber’s method), was composed of mono-dispersive spherical particles with an average diameter of 0.59 µm. The St-sol enhanced the EPD rate and proportionally increased the sol content with the starting EPD composition. Both silica sols showed substantial binding strength as durable property of the zeolite/silica-sol deposits against peeling from the surface of the substrate in agitating water. The prepared zeolite/silica sol deposit using both types of silica sols showed adsorption of Pb2+ ions from an aqueous solution, which suggest prepared modules will be useful for removing hazardous cations from polluted solutions.
