INHOMOGENEOUS DISTRIBUTION OF TIO2 IN POR OUS-GLASS SPECIMEN ANCHOREDBY IMPREGNATION METHOD USING AQUEOUS-SOLUTIONS

Porous glass, haring a pore size of around 10 nm in diameter, was prep ared from fluorine containing sodium borosilicate glass by treatments of phase-separation and acid leaching. A titanium oxide was anchored o nto a platelet porous glass specimen of 0.5 mm in thickness by impregn ating with aqueous solution of titanium(III) chloride or titanium(N) s ulfate. The distribution of titanium concentration was homogeneous in the porous glass specimen as dried. However, in the specimen which was impregnated with a larger amount of TiO2 and heated in the temperatur e range of 200 to 500 degrees C, The Ti-distribution was inhomogeneous showing a higher Ti-content in two areas on both side of the center o f specimen.