【作者】 崔会东；

【导师】 吕晓龙；

【作者基本信息】 天津工业大学 ， 材料学， 2007， 硕士

【摘要】 现阶段在膜应用过程中最大问题是膜污染问题，国内外的研究往往都是通过对膜本体材料的选择，膜表面的改性、膜应用工艺的优化等方面进行研究减缓膜污染的问题，很少针对膜的纵向深层结构来研究膜污染问题。膜纵向结构有对称性结构(均质结构)与非对称性结构(皮层结构)。目前已知聚偏氟乙烯中空纤维亲水性膜是抗污染性较强的一种膜材料。本文首先通过用不同浓度的溶剂(DMAc)对聚偏氟乙烯外压中空纤维亲水性超滤膜外表面浸泡处理，使膜外皮层孔结构处于不同状态，表征表面孔结构变化。然后通过改变纺丝制膜工艺制得泡点压力与通量相当但表面孔结构不同的两种中空纤维膜，一种中空纤维膜外表面光滑，膜孔颈在膜表面，定义为A型孔结构膜，另一种中空纤维膜表面相对粗糙，膜孔颈位于膜外表面层下，定义为V型孔结构膜。通过用这两种不同孔结构的亲水性超滤膜过滤卵清蛋白、淀粉、二氧化硅、柴油等四种典型体系，考察膜通量衰减情况，研究膜孔结构与膜耐污染性能关系；然后改变不同的过滤工艺条件研究膜通量的衰减情况，进一步研究膜孔结构和其抗污染性能的关系，研究表明：V型孔结构膜较A型孔结构膜耐污染。接着对污染程度相当的两种孔结构膜，在一定的压力下反洗一定时间；对应不同的污染体系，采用不同的化学药剂清洗，研究通量恢复情况，研究表明：V型孔结构膜较A型孔结构膜易清洗。为了进一步的提高膜的耐污染性能，对两种结构的膜表面进行涂覆改性，通过过滤卵清蛋白和柴油两种典型易污染体系研究膜表面耐污染情况，发现涂覆改性后的中空纤维复合膜耐污染性有了明显的提高，主要原因是膜表面引入了亲水性基团提高了膜的亲水性。更多还原

【Abstract】 As we know, today, the difficult problems are fouling of membrane during the application of membrane. Many ways, such as, the elect of membrane material, membrane surface-modified, the optimization design of membrane application technological conditions, have ever been studied in domestic and abroad; but few people do research on pore structure of membrane. Membrane pore structure includes symmetrical pore and asymmetrical pore. Now we know PVDF is a kind of material that has the greater anti-fouling property. In this article, two kinds of PVDF UF membrane with different outer surface pore structure but equivalent bubble point pressure and water flux were prepared by changing spinning condition, the one whose necks of pores lie on the surface of the membrane is smooth, this pore structure is named A model pore; the other one whose necks of pores are under membrane surface is relative rough this pore structure is named V model pore. Then, attenuation curve of membrane flux is studied through filtering representative different solution systems and changing different filtration conditions, and further illuminate the relation between membrane pore structure and anti-fouling. The results show that V model pore of membrane has better anti-fouling property. In succession, membrane that has dissimilar exterior configuration but the same fouling is washed reversely by water, and then different contaminative system is cleaned out by different chemical medicine, further reversion conditions of flux is researched. As a result, V model pore of is cleaned out easily. For the sake of improving anti-fouling property further, PVDF hollow fiber composition membrane is prepared by coating PVA on the surface of membrane. The results that the performance of anti-fouling is improved by coating PVA are demonstrated through filtering ovalbumin system and diesel oil system.更多还原