PVDF亲水复合膜的制备及表征

Preparation and Characterization of PVDF Hydrophilic Composite Membrane

聚偏氟乙烯(PVDF)膜材料存在强疏水性的缺陷,亲水化改性是解决该问题的主要途径。以PVDF为基膜材料、聚乙烯醇(PVA)为共混材料、N,N-二甲基乙酰胺(DMAc)为溶剂,采用相转化法制备PVDF/PVA复合膜。考察了复合膜的PVDF/PVA共混比、固含量、低分子化合物添加剂、聚合物添加剂等非溶剂添加剂对复合膜接触角的影响。结果表明,当PVDF/PVA共混比为7/3,固含量为13%时,制备的复合膜接触角为22.92°;当添加剂为无水氯化锂、纳米二氧化硅、聚乙烯吡咯烷酮(PVP)时,复合膜接触角分别从53.12°、30.51°和41.89°都降低到了0°,亲水性提高,其中纳米二氧化硅作为添加剂时复合膜亲水性最好;当添加剂为丙三醇、PMMA、PEG时,复合膜接触角都增大,亲水性变差。

The strong hydrophobicity of polyvinylidene fluoride(PVDF) membrane materials is its main drawback, and hydrophilization modification is the main way to solve this problem. The PVDF/PVA composite membrane was prepared by phase inversion method using PVDF as the base material, polyvinyl alcohol(PVA) as the blending material and N,N-dimethylacetamide(DMAc) as the solvent. The effects of blending ratio of PVDF/PVA, solid content, small molecule additives and polymer additives on the contact angle of the composite film were investigated. The results showed that when the PVDF/PVA blending ratio is 7/3 and the solid content is 13%, the contact angle of the prepared composite membrane is 22.92°;when the additive is anhydrous lithium chloride, nano-silica, and PVP, the contact angle of the composite film is reduced from 53.12°, 30.51° and 41.89° to 0°, respectively. The composite film has the best hydrophilicity when nano-silica is used as an additive. When the additive is glycerin, PMMA, PEG, the contact angle of the composite film increases, and the hydrophilicity deteriorates.