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以强碱、强氧化剂溶液对聚偏氟乙烯(PVDF)微孔滤膜表面极化改性后,用自由基聚合的方法将α-甲基丙烯酸接枝到PVDF微孔滤膜表面,得到pH值敏感型微孔滤膜。结果表明:接枝率确定的情况下,水通量随着被过滤溶液pH值的变化而明显变化;接枝率的逐步升高,水通量呈现先增大后减小的趋势。接枝膜经扫描电子显微镜和原子力显微镜测试表明,接枝膜表面孔数减少,孔径变小,并且观察到孔内有絮状物,证明接枝甲基丙烯酸的存在。为了兼顾改性膜的水通量和pH值敏感性能,需要将膜的接枝率控制在1.9%~6.1%之间。
After the surface of polyvinylidene fluoride (PVDF) microporous membrane was polarization modified by strong alkali and strong oxidant solution, α-methacrylic acid was grafted to the surface of PVDF microporous membrane by free radical polymerization to obtain pH Value-sensitive microporous membrane. The results show that the water flux changes obviously with the pH value of the filtrate solution when the grafting rate is determined. With the grafting rate increasing, the water flux increases first and then decreases. Graft film by scanning electron microscopy and atomic force microscopy tests showed that the number of pores on the surface of the graft membrane decreases, the pore size becomes smaller, and the presence of a floc in the pores is evidenced by the presence of the grafted methacrylic acid. In order to balance the membrane water flux and pH sensitivity, it is necessary to control the grafting rate of the membrane between 1.9% and 6.1%.