论文部分内容阅读
采用溶胶-凝胶相转化法,将廉价且耐酸碱的聚氯乙烯(PVC)和耐高温、高强度的硅酸钙共混制备出超滤膜。研究了硅酸钙加入量对膜分离性能的影响;利用扫描电镜分析了膜表面和断面的形貌;考察了共混膜的机械性能、热稳定性能及耐酸、耐碱性能。结果表明:在硅酸钙含量为5%(质量分数)时,共混膜具有良好的机械强度、热稳定性及耐碱腐蚀性能。在0.4MPa过膜压力下持续运行5h,对牛血清蛋白(BSA)的截留率保持在98%~96%;在0.2MPa,50℃下持续运行5h时,其对BSA的截留率保持在92%以上。将共混膜在pH=12的强碱溶液中浸泡12h,膜面无明显损伤,截留率基本无下降;在pH=2的强酸中浸泡12h,膜面损伤明显,截留率明显下降。
An ultrafiltration membrane was prepared by blending sol-gel phase inversion method with cheap and acid-resistant polyvinyl chloride (PVC) and high temperature resistant and high strength calcium silicate. The effects of calcium silicate dosage on membrane separation performance were investigated. The morphology of the membrane surface and cross section were analyzed by scanning electron microscopy. The mechanical properties, thermal stability and acid and alkali resistance of the blend membrane were investigated. The results show that the blending film has good mechanical strength, thermal stability and alkali corrosion resistance when the content of calcium silicate is 5% (mass fraction). Under the pressure of 0.4 MPa, the BSA retention rate kept at 98% ~ 96% for 5 h, while the retention rate of BSA was maintained at 92% at 0.2 MPa and 50 ℃ for 5 h %the above. The membrane was immersed in strong alkaline solution of pH = 12 for 12h, the membrane surface was not damaged obviously, and the rejection rate was almost unchanged. After being soaked in strong acid at pH = 2 for 12h, the membrane surface was obviously damaged and the rejection was significantly decreased.