【摘要】 为制备超高水通量聚偏氟乙烯(PVDF)超滤膜,以溶液结晶–聚合物扩散(CCD)法为基础,无水氯化锂(LiCl)作为致孔剂和亲水改性剂,N,N–二甲基乙酰胺作为溶剂,采用共混法制备PVDF/LiCl超滤膜。通过扫描电子显微镜对PVDF/LiCl超滤膜的断面结构进行表征,分析证明超滤膜内部存在较好的联通结构,并且生成了大孔结构与指状孔结构。接触角及成膜动力学测试结果表明,LiCl质量分数为2%时,超滤膜的亲水性最好,成膜速率最快。水通量与截留率测试结果显示,随着LiCl含量增加,超滤膜在水通量急剧增大的基础上,截留率下降幅度小,LiCl质量分数为1%时综合性能最佳,水通量为1 190.48 L/(m~2·h),截留率为83.21%,通量恢复率达到84.46%。CCD法制备的PVDF/LiCl超滤膜在处理水污染领域具有巨大的可发展潜力。更多还原

【Abstract】 In order to prepare ultra-high water flux polyvinylidene fluoride (PVDF) ultrafiltration membrane,with anhydrous lithium chloride (LiCl) as poreforming agent and hydrophilic modifier,and N,N-dimethylacetamide as solvent,PVDF/LiCl ultrafiltration membrane was prepared by blending method based on solution crystallization polymer diffusion (CCD) method.The cross section structure of PVDF/LiCl ultrafiltration membrane was characterized by scanning electron microscopy.It was proved that there was a good interconnection structure in the membrane,and the macroporous structure and fingerlike pore structure were generated.The test results of contact angle and film forming kinetics showed that the best hydrophilicity and the fastest film forming rate were obtained when the content of LiCl was 2%.The test results of water flux and rejection rate showed that the rejection rate of the ultrafiltration membrane decreased slightly when the water flux increased sharply.The best performance was achieved when the content of LiCl was 1%,the water flux was 1 190.48 L /(m~2·h),the rejection rate was 83.21%,and the flux recovery rate reached 84.46%.CCD PVDF/LiCl ultrafiltration membrane has great potential in the field of water pollution treatment.更多还原