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采用干-湿相转化法制备了PVDF/CaCO3共混中空纤维膜,考察了芯液组成和外凝胶浴温度对共混膜结构和性能的影响。结果表明,随芯液中酸含量增加,膜纯水通量迅速升高,BSA截留率略有下降;膜拉伸强度下降,断裂伸长率增加。SEM图显示,膜断面指状孔的数量增多、支撑层厚度变薄、膜亚层海绵孔增加;相应孔隙率升高,而泡点压力略微下降。当外凝胶浴温度较高时,膜支撑层和外皮层较为致密,导致膜纯水通量明显下降,同时BSA截留率在80℃高温外凝胶浴时,由于膜外皮层上出现少量大孔结构,而迅速下降为62.55%。
The PVDF / CaCO3 blends were prepared by dry-wet phase inversion method. The influences of the composition of the core liquid and the temperature of the outer gel bath on the structure and properties of the blends were investigated. The results showed that the flux of membrane pure water increased rapidly with the increase of the acid content in the liquid and the rejection of BSA decreased slightly. The tensile strength of the membrane decreased and the elongation at break increased. The SEM images show that the number of finger-like pores in the film section increases, the thickness of the support layer becomes thinner, and the sponge pores in the film sublayer increase; the corresponding porosity increases and the bubble point pressure decreases slightly. When the temperature of the outer gel bath is higher, the membrane support layer and the outer skin layer are denser, resulting in a significant decrease in membrane pure water flux. Meanwhile, when the BSA rejection rate is higher than 80 ° C, The pore structure decreased rapidly to 62.55%.