高亲水性海藻酸钠膜渗透汽化分离甲醇水溶液

High water selectivity sodium alginate hybrid membranes for pervaporation of methanol/water mixtures

在海藻酸钠基质中引入磷钨酸颗粒,制备了一种高亲水性渗透汽化杂化膜。由热失重等分析手段对膜进行了表征,并在不同温度下(30～60℃)通过分离80%～95%的甲醇水溶液,测试了杂化膜的渗透汽化性能,实验结果表明:添加了磷钨酸的杂化膜,其分离性能显著高于纯海藻酸钠膜,当磷钨酸含量为6%时,30℃下分离水含量5%的溶液,膜通量达到318.2 g/(m2 h),分离因子达到656.9,分别是纯海藻酸钠膜的3.7倍和26.3倍。利用阿累尼乌斯关系式考察了膜通量与温度之间的关系,发现溶液通过膜的活化能随着磷钨酸含量的增加而降低。表明,磷钨酸的加入使得渗透物在杂化膜内更容易透过。

Highly water selective pervaporation hybrid membranes were prepared by incorporating phosphotungstic acid（PTA） into sodium alginate（SA）.The resulting membranes were characterized by thermogravimetric analysis（TGA）.The membranes were tested for pervaporation dehydration of methanol at a higher methanol concentration of 80%─95% in the temperature range of 30～60℃.Experimental results demonstrated that with the addition of PTA the separation performance of hybrid membranes was notably improved.With 6% addition of PTA,the membrane separated 5% water solution at 30 ℃,total flux was 318.2g/（m2 h） and separation factor was 656.9,improved by more than 3.7 times and 26.3 times respectively.From the temperature dependency and permeation values,the Arrhenius activation parameters were estimated.The activation energy of all membranes decreased with increasing amount of PTA.It suggested that permeation was more easy through the hybrid membranes with the addition of PTA.