铸膜液熟化时间对PVDF高度疏水微孔膜结构和性能的影响OA

The article employs the micro-molding in conjunction with non-solvent induced phase separation(NIPS)method to fabricate highly hydrophobic polyvinylidene fluoride(PVDF)microporous membranes.The casting substrate is an aluminum plate,N-methyl-2-pyrrolidone(NMP)serves as the solvent,and water acts as the coagulant.The study investigates the effects of the maturation time of the casting solution on phase separation behavior and the structure and properties of the membrane under the synergistic action of micro-molding.The results indicated that the method not only replicated the micrometer-scale roughness of the template but also slowed down the phase transformation rate through adhesion constraints,which was conducive to solid-liquid phase separation and the coarsening of nuclei,ultimately forming a micro-nano composite hierarchical structure.Meanwhile,the extended maturation time promoted the formation of primary crystals,transforming the instantaneous liquid-liquid phase separation into solid-liquid phase separation.As a result,the hydrophobicity of the membrane was significantly enhanced,with the water contact angle reaching up to 144.46°,indicating that this composite membrane structure can trap more air.Moreover,the other properties of the membrane also surpassed those of the membrane prepared solely by the NIPS method.