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以筛孔75μm涤纶网为基衬,N,N-二甲基甲酰胺、丙酮为混合溶剂(质量比8:2),采用静电纺丝法制备了PVDF-HFP/Si NPs疏水复合膜,考察了疏水气相纳米Si O2颗粒(Si NPs)对纳米纤维膜结构及性能的影响。结果表明,随着纺丝液中Si NPs含量的增加,其红外特征吸收峰将愈发明显;膜厚度上升,而孔隙率却随之降低;尽管加入Si NPs后,膜的平均孔径变大,但膜表面疏水性的提高则保障了复合膜在膜蒸馏过程中仍可保持优异的截留性能。以质量浓度35 g/L的Na Cl溶液为进料液进行直接接触式膜蒸馏脱盐实验,当进料温度和渗透温度分别为53℃和20℃时,各复合膜盐截留率均能达到99.99%以上,膜通量可达12.0 kg/(m2·h)。
PVDF-HFP / Si NPs hydrophobic composite membranes were prepared by electrospinning method using a 75μm polyester mesh as the backing, a mixed solvent of N, N-dimethylformamide and acetone (mass ratio of 8: 2) Effects of hydrophobic gas phase nano - Si O2 particles on the structure and properties of nanofibrous membranes. The results show that with the increase of Si NPs content in spinning solution, the infrared absorption peak will be more obvious; the film thickness will increase while the porosity will decrease. Although the average pore size of Si NPs increases, However, the improvement of the surface hydrophobicity of the membrane ensures that the composite membrane can still retain excellent retention performance during the membrane distillation. Direct contact membrane desalination with Na Cl solution of 35 g / L concentration was used as feed solution. When the feed temperature and infiltration temperature were 53 ℃ and 20 ℃, the salt rejection of each composite membrane could reach 99.99 %, Membrane flux up to 12.0 kg / (m2 · h).