SiO_2-PWA/PVDF杂化阳离子交换膜的制备及性能研究

Preparation and properties of SiO_2-PWA/PVDF hybrid cationic exchange membrane

膜法钴电积工艺中使用的阳离子交换膜需要有很高的氯离子阻挡性能和耐酸、耐氧化性能,针对这一问题,采用共混热压法制备出了二氧化硅固定磷钨酸的聚偏氟乙烯(SiO2-PWA/PVDF)杂化阳离子交换膜.以电解时膜的氯离子泄漏率为评价指标,研究了膜的氯离子阻挡性能和耐酸、耐氧化性能,并使用SEM,FTIR对膜的微观形貌和功能基团进行表征.结果表明,在TEOS与PWA的摩尔比为5∶1,SiO2-PWA添加质量分数为20%,热压温度为180℃的条件下,制备出的杂化阳离子交换膜性能最佳,氯离子泄漏率为7.5%,耐酸、耐氧化性能相对较好,具有应用于膜法钴电积工艺的潜力.

The cation exchange membranes for cobalt electrowinning usage need to have excellent barrier property to chloride ion,and high acid and oxidation resistance.To address this problem,polyvinylidene hybrid cation exchange membrane of silica immobilized phosphotungstic acid(SiO2-PWA/PVDF)was prepared by hot-pressing method.The leakage rate of chloride ion was used as the evaluation index to study the chloride ion barrier property and acid resistance and oxidation resistance of the membrane,and the surface morphology and functional group of the membrane were characterized by SEM and FTIR.When the molar ratio of TEOS to PWA was 5∶1,the additive mass fraction of SiO2-PWA was 20%and the hot pressing temperature was 180℃,the hybrid cation exchange membrane has the best performances.The leakage rate of Cl-was 7.5%,and the acid and oxidation resistance was relatively good.The hybrid cation exchange membrane has the potential to be applied to the cobalt electrowinning by membrane.