真空膜蒸馏法处理NaCl水溶液超疏水性PVDF膜性能的优化

Performance Optimization of Highly Hydrophobic PVDF Membrane for Treatment of Aqueous NaCl Solution by Vacuum Membrane Distillation

摘要: 采用正交实验设计方法，以纯水和0.03 g/L NaCl水溶液为料液，依据真空膜蒸馏(VMD)实验特性，选择了聚偏氟乙烯(PVDF)超疏水微孔膜的优化制备条件。结果表明由直观分析法和直接测量法分别确定的优化制膜条件基本一致。用于VMD的PVDF微孔膜的优化制膜条件为：铸膜液体系组成及质量分数为15%PVDF/51%TEP34%DMAc，第1凝固浴中混合溶剂(TEPDMAc)总质量分数为60%，膜厚度为0.17 mm，第1凝固浴中TEP与DMAc的质量比为60∶40；在该条件下，NaCl的脱除率可达99.90％以上。

Abstract: The highly hydrophobic membranes were applied in the vacuum membrane distillation(VMD) of pure water and 0.03 g/L aqueous NaCl solution. Orthogonal method was employed to optimize the preparation of PVDF membrane. The result of designdirect analysis was consistent to that of direct measurement. The optimized conditions are: the mass fractions of casting solution are 15% PVDF/51% TEP34% DMAc; the mass fraction of mixed solvent(TEPDMAc) in the first coagulation bath is 60%; the membrane thickness is 0.17 mm; the mass ratio of TEP to DMAc in the first bath is 60∶40. The removal rate of NaCl can be over 99.90%.