【作者】 吕亚文；

【导师】 王湛； 李政雄；

【作者基本信息】 北京工业大学 ， 环境工程， 2001， 硕士

【摘要】 为解决膜应用过程中的膜污染问题，本文进行了聚偏氟乙烯（PVDF）抗污染膜的研制及其特性研究。在总结大量文献的基础上，以醋酸纤维素（CA）作为第二种聚合物组分，选择溶液共混法对疏水性的聚偏氟乙烯（PVDF）超滤膜进行亲水化改性，利用粘度法、DSC扫描等多种手段对聚偏氟乙烯（PVDF）和醋酸纤维素（CA）的相容性作了较深入的探讨，并采用相转化法流延成膜，对影响膜性能的主要因素进行了考察，测试了膜的孔隙率、泡点压力、化学稳定性、抗污染性能及亲水性等。 结果表明，聚偏氟乙烯（PVDF）和醋酸纤维素（CA）属于不完全相容体系，在PVDF中混入CA可以增加膜表面的亲水性，提高其抗污染能力；当聚偏氟乙烯和醋酸纤维素共混比为9:1，聚合物含量为18％时，共混膜的阻力增大系数为0.43，分别比相同纯水通量和相同制膜条件的纯PVDF膜减少0.2和0.48。研究表明体系中的共混比、添加剂的种类和含量以及凝胶浴组成均对膜性能有较大影响，在PVDF/CA=9/1，聚合物浓度为15％，添加剂为氯化锂的情况下，可以制得水通量较大、截留率较高、韧性较好的优质超滤膜，其纯水通量为49.5mL/cm~2.h，对卵清蛋白的截留率大于96％。更多还原

【Abstract】 In order to solve fundamentally the problem of membrane fouling in membrane separation process, the preparation and characteristics of anti-fouling ultrafiltration membranes were studied in this dissertation. Polymer blending to hydrophilized poly(vinylidene fluoride) (PVDF) ultrafiltration membrane was selected after reviewing a lot of literature, cellulose acetate (CA) was introduced as the second polymer due to its hydrophilicity. The compatibility of PVDF and CA were characterized by viscosity and DSC etc. Phase-inversion process was adopted to make membranes, and the effects of various preparative conditions on blend membrane were studied, and then the porosity, critical air bubble pressure, chemical stability, hydrophilicity and anti-fouling characteristics of the membrane were tested. It was indicated that the blend system of PVDF/CA is compatible in part, the hydrophilicity of PVDF was increased by blending with CA and thus the preformance of the membrane were improved. When the blend ratio of PVDF/CA=9/1, the content of polymer is 18%, the coefficient of resistance increment of alloy membrane is 0.43, decreasing 0.2 and 0.48 comparing with the pure PVDF membrane under the condition of the same permeation and the same process respectively. And also it was proved that the membrane characteristics were affected by blend ratio, type and content of additives and composition of precipitator. When PVDF/CA=9/1, polymer content is 15%, LiCI as the additive, the better membrane which has greater pure water permeation, higher rejection and better tenacity was obtained, whose pure water permeation is 49.5mL/cm2.h, the rejection of protein is more than 96%.更多还原