硅溶胶填充改性PDMS-PA复合膜

Modification of PDMS-PA Composite Membrane by Filling Hydrophobic Nano-silica Sol

在聚二甲基硅氧烷(PDMS)中填充质量分数为20wt%、25wt%和30wt%的疏水纳米二氧化硅溶胶作为表面皮层,以聚酰胺(PA)为支撑层,制备出改性硅橡胶-聚酰胺(PDMS-PA)复合膜。扫描电镜(SEM)观察发现二氧化硅颗粒均匀分布在PDMS基体中,改性皮层与PA支撑层结合紧密。用5%的乙醇水溶液对改性膜在不同温度下进行渗透汽化测试,发现填充比例为20wt%的膜的分离因子较未改性膜可提升25%,而填充比例为25wt%和30wt%时,膜的分离因子却低于未改性膜。这显示在PDMS中填充某种比例的硅溶胶可改善膜的分离性能。

Medified Poly （dimethylsiloxane）-Polyamide （PDMS-PA） composite membranes have been prepared by idling hydrophobic nanosilica sol into the PDMS skin layers at weight concentrations of 20%, 25% and 30%. By scanning electron microscopic pictures shows that SiO2 particles disperse in the PDMS layers evenly and the modified skin layer combines with the PA supporting layer tightly. Their pevaperation performances were tested with 5% aqueous ethanol solution at different temperature. It was found that the separation factor could get a 25% rise after falling silica sol at 20wt.%. However, the separation factors decreased under the conditions of fLlling silica sol at 25wt.% and 30wt.%. It indicates that filling some amount of hydrophobic nano-silica sol could improve pervaporation performance of PDMS--PA composite membranes.