【作者】 韩娟娟；

【导师】 苑会林；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2012， 硕士

【摘要】 本文利用多种方法制备出不同孔径，不同性能的微孔膜。本课题采用了钢带流延法、热致相分离法（TIPS）、浸没沉淀法。并通过扫描电子显微镜、水通量测试、孔隙率测试、红外、DSC、平均孔径测试等，得到了性能各异的微孔薄膜。浸没沉淀法是采用N,N-二甲基乙酰胺（DMAC），并选择了聚乙二醇1000（PEG1000）、聚乙烯吡咯烷酮（PVP）、LiCl等为助剂，并选择一定比例的水和乙醇作为萃取剂，得到不同性能的微孔膜。其中以5%的PVP为添加剂，PVDF质量分数为21%，萃取剂中水和乙醇的比例为3：7时，能得到膜孔径大小大约0.1微米级，机械强度较大的微孔膜。但是此种方法重复性差，工艺复杂，影响因素多。钢带流延法是分别采用N,N-二甲基乙酰胺（DMAC）和N-甲基吡咯烷酮（NMP）为溶剂，将配置好的溶液均匀的涂布在钢带上，辅以一定的成膜温度，得到一定孔径的微孔膜。溶液流延法得到的微孔膜，结晶规则，膜呈现半透明状，孔径大约在几十微米左右。此种方法制备的PVDF微孔膜适合用在水处理的微滤膜，并且工艺简单。热致相分离法（TIPS）是分别采用邻苯二甲酸二甲酯（DMP）和邻苯二甲酸二丁酯（DBP）为溶剂，以及一些致孔剂，并且选用不同的冷却方法：常温空气冷却和冰水冷却，通过电镜以及水通量和孔隙率的测定，最后得到，当PVDF质量分数为40%，溶剂为DBP，空气冷却，得到孔隙率为65%的微孔膜。此种方法工艺简单，结构完善，膜孔径小且均匀。更多还原

【Abstract】 In this paper, I perpare the PVDF microporous membrane via steel beltcasting,thermally induced phase separation and Immersion precipitation.These microporous membranes have different aperture, different properties.The product is characterized by SEM, water flux and porosity, IR, DSC,diameter.In immersion precipitation, I use N-dimethylacetamide(DMAC) as solvent,PVP, PEG and LiCl as porogen. I also investigate the effect of coagulationbath, the proportion of water and ethanol. In conclusion, the best is to chooseDMAC as solvent, the concentration of PVDF is21%, adding5%PVP, andthe proportion of water and ethanol is7:3. Using this method, I can preparethe PVDF microporous membrane with few microns in diameter,and goodmechanical strength. But this method repeatability is poor, process complex,and many influences.In steel belt casting method, I use N-dimethylacetamide (DMAC) andN-methyl pyrrolidone (NMP) as solvent. The configured solution evenly coatson steel belt, and combine with a certain casting temperature. Microporous membrane prepared by steel belt casting, has good crystallization, themembrane presents a translucent, and the pore size is about tens of microns.PVDF microporous membranes prepared by this method is suitable formicrofiltration membranes used in water treatment, and the process ofpreparation is simple.In thermally induced phase separation, I choose DBP and DMP as solvent. Ialso investigate the effects of concentration of solvent, cooling rate andporogen in PVDF membrane. The product is characterized by SEM, water fluxand porosity. In conclusion, the best is to choose DBP as solvent, theconcentration of PVDF is40%, air cooling. By this method,the porosity ofmicroporous membrane65%. The production process of this method issimple.The membrane has good structure and small aperture.更多还原