有机硅烷改性PDMS/Silicalite渗透汽化杂化膜制备及其分离性能

Preparation of Silane Modified PDMS/Silicalite Hybrid Membrane and Its Pervaporation for Dilute Ethanol-Water Solution

采用硅烷偶联剂对全硅沸石Silicalite-1进行表面改性,以聚二甲基硅氧烷(PDMS)为基体,制备了渗透汽化PDMS/Silicalite杂化膜.用FT-IR,TGA等对改性的效果和杂化膜的热稳定性能进行了表征,并以低浓度乙醇/水体系为研究对象,以渗透通量和分离因子为评价指标,考察了料液组成、进料温度、循环流速、膜下游侧真空度等因素对改性杂化膜分离性能的影响.结果表明,硅烷改性沸石所制杂化膜对低浓度乙醇/水体系的分离因子比空白膜和未改性杂化膜分别提高136%和45%.随料液中乙醇浓度从5%增加到69%,膜分离因子从22降低到7,而其他因素对膜的选择性影响较小.

With 3-aminopropyltrlethoxysilane as a coupling and surface modification agent for Silicalite-1 nanoparticles, polydimethylsiloxane （PDMS）-Silicalite filled pervaporation membranes were prepared. The modification effect of Silicalite and thermal resistant performance of the hybrid membrane were investigated by FT-IR and TGA. The effects of feed concentration, feed temperature, feed flow rate and downstream vacuum degree on the pervaporation performance of dilute ethanol/water solutions were also examined. The results showed that compared with pure PDMS and unmodified hybrid membranes, the selectivity of silane modified hybrid membrane could be improved by 136% and 45%. With the increasing of ethanol concentration in the feed from 5% to 69%, the membrane selectivity was decreased remarkably. Nevertheless, other operation parameters had a little effect on membrane selectivity.