微相分离制备大分子接枝PAN纳滤膜及性能研究

发布时间：2018-07-10 09:12

本文选题：聚丙烯腈 + 丝朊　；参考：《天津工业大学》2017年硕士论文

【摘要】：基于仿生学的思想,以氯化锌水溶液为溶剂,通过丝朊均相接枝聚丙烯腈得到铸膜液,然后将其放入水的凝固浴中,锌离子和氯离子逐渐扩散到水中,丝朊和聚丙烯腈发生相转变成膜。锌离子和氯离子起到致孔的作用,而丝朊和聚丙烯腈发生微相分离,在其界面也形成离子致孔的水通道,因此得到的丝朊接枝聚丙烯腈(SF-g-PAN)过滤膜孔径分布窄,亲水性好。通过扫描电子显微镜(SEM)、傅里叶红外光谱(FTIR)、热重分析(TG-DTG)和水接触角等方法对膜进行了表征。以不同分子量染料溶液探究了 SF-g-PAN过滤膜的过滤性能,SF-g-PAN过滤膜对于分子量大于660的染料直接黄27(Mw=662.62 Da)的截留率可以达到96%以上,对苋菜红(Mw= 604.47 Da)的截留率为30%。结果表明SF-g-PAN过滤膜具有精细分离性能和pH响应性。牛血清蛋白(BSA)溶液过滤实验中稳定后BSA水溶液的通量约为纯水通量的86.39%,表明SF-g-PAN过滤膜具有较好的抗污染性能。以葡聚糖为聚合物骨架,丙烯腈为单体,氯化锌水溶液为溶剂制备了葡聚糖接枝聚丙烯腈过滤膜(De-g-PAN)。通过SEM、FTIR、TG-DTG、水接触角等方法对过滤膜进行表征。讨论了不同葡聚糖含量的De-g-PAN过滤膜对不同分子量染料的截留和通量。结果表明,De-g-PAN过滤膜对分子量高于660的染料分子具有良好的去除效果,同时随葡聚糖含量的增加,过滤膜对染料的截留率升高,通量减小。De-g-PAN过滤膜对BSA和乳化油具有良好的抗污染性能,葡聚糖含量的增加在一定程度上提高了膜的抗污染性能。在过滤过程中起主要作用的仍为PAN高分子,因此随后我们讨论了两种不同方法制备的PAN膜的过滤性能。通过使用氯化锌、二甲基甲酰胺两种不同溶剂线路的方法成功制备出不同结构的PAN过滤膜。通过SEM、3D超景深显微镜、激光共聚焦显微镜对膜在干湿状态下的形貌进行表征,通过XRD、水接触角、力学性能比较了两种膜的结构性能。两种溶剂制备对不同分子量染料的截留表明,以氯化锌为溶剂制备的PAN膜孔径分布较窄,同时具有较好的抗污染性能。
[Abstract]:Based on the idea of bionics, the casting film solution was obtained by homogeneous grafting of polyacrylonitrile with silk prion in aqueous solution of zinc chloride, and then it was put into the coagulation bath of water. Zinc ion and chloride ion gradually diffused into water. Silk prion and polyacrylonitrile are transformed into films. Zinc ion and chloride ion play a role in pore formation, while silk prion and polyacrylonitrile are separated in microphase and the water channel of ion induced pore is formed at its interface. Therefore, the pore size distribution and hydrophilicity of silk prion grafted polyacrylonitrile (SF-g-PAN) membrane are narrow and hydrophilic. The films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG-DTG) and water contact angle. The filtration performance of SF-g-PAN filtration membrane was studied by using different molecular weight dye solutions. The rejection rate of SF-g-PAN filter membrane for direct yellow 27 (MwN 662.62 Da) with molecular weight greater than 660 was over 96%, and that for amaranth (MW = 604.47 Da) was 30%. The results show that SF-g-PAN filtration membrane has fine separation performance and pH response. In the filtration experiment of bovine serum protein (BSA) solution, the flux of stable BSA solution is about 86.39 of pure water flux, which indicates that SF-g-PAN filtration membrane has better anti-fouling performance. Using dextran as polymer skeleton, acrylonitrile as monomer, zinc chloride aqueous solution as solvent, De-g-PAN was prepared by grafting polyacrylonitrile (De-g-PAN). The filtration membrane was characterized by SEM-FTIR TG-DTG and water contact angle. The retention and flux of different molecular weight dyes by De-g-PAN filtration membrane with different dextran content were discussed. The results showed that De-g-PAN filtration membrane had a good removal effect on dye molecules with molecular weight higher than 660, and the retention of dyes increased with the increase of dextran content. De-g-PAN filtration membrane has good anti-fouling performance on BSA and emulsified oil, and the increase of dextran content improves the anti-fouling performance of the membrane to some extent. Pan polymers still play a major role in the filtration process, so we discussed the filtration performance of pan membranes prepared by two different methods. Pan filtration membranes with different structures were successfully prepared by using zinc chloride and dimethylformamide two different solvent lines. The morphology of the films in dry and wet state was characterized by SEMM-3D hyper-depth microscope and laser confocal microscope. The structure and properties of the two films were compared by XRD, water contact angle and mechanical properties. The retention of different molecular weight dyes by the preparation of two solvents showed that the pore size distribution of pan membrane prepared with zinc chloride as solvent was narrow and had good antifouling performance.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.893

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