关键词: 硅溶胶;纳滤膜;溶胶浓度;烧结温度

Abstract: SiO2 nanofiltration membrane was prepared on 50 nm ultrafiltration support by impregnation method using silica sol with average diameter of 10 nm and 80 nm as raw material .The effects of sintering temperature on the membrane density and porosity , phase composition , thermal expansion and microstructure were investigated .The influence of sol concentration on film thickness was explored , and the suitable sintering temperature and coating process were determined .The results show that the density of SiO2 nanofiltration membrane is increased with the raising of temperature up to 800 ℃, and a cristobalite phase is formed when the temperature up to 850 ℃, which leads to the expansion of the membrane change greatly at about 200 ℃.600 ℃and 700 ℃are the appropriate sintering temperature for 10 nm and 80 nm silica sol respectively .A nanofiltration membrane with uniform microstructure and 1μm thickness was obtained coating with 10 nm silica sol in 16.9wt％concentration and sintering at 600℃.

Key words: silica sol;nanofiltration membrane;sol concentration;sintering temperature