基于表面偏析功能化超滤膜的制备及其性能研究

发布时间：2018-04-04 09:55

本文选题：超滤膜　切入点：表面偏析　出处：《天津大学》2015年硕士论文

【摘要】：功能化超滤膜在水处理、生物分离、药物控制释放等领域具有良好的应用前景。目前,设计和制备功能化超滤膜的方法主要包括表面接枝、表面涂覆等,存在易使膜孔堵塞、步骤繁琐、成本高等缺点,限制了功能化超滤膜的发展与应用。表面偏析作为一种原位的、三维的改性方法,可在膜表面产生有效的功能性高分子刷,受到国内外学者的广泛关注。本论文基于表面偏析制备出功能化超滤膜,具体工作如下:基于自由表面偏析制备具有pH响应性的超滤膜。通过自由基接枝聚合的方法在Pluronic F127分子上接枝具有pH响应性的聚甲基丙烯酸(PMAA)链段,制备出不同接枝聚合度的两亲性嵌段共聚物PMAAn-F127-PMAAn。系统的考察了PMAA链段接枝聚合度对PES/PMAAn-F127-PMAAn超滤膜的表面化学组成、表面亲水性、表面电荷、pH响应性能的影响。研究表明,在成膜过程中pH响应性PMAA链段发生了自由表面偏析,且随着PMAA链段接枝聚合度的增加,PMAA在膜表面的覆盖度增加。PES/PMAAn-F127-PMAAn超滤膜具有显著的、可逆的和持久的pH响应性能,且随PMAA表面覆盖度的增加,膜的pH响应性程度增大。基于自由表面偏析制备具有抗污染性能的超滤膜。通过沉淀共蒸馏的方法在碳纳米管(CNT)壁上接枝两性离子甲基丙烯酸磺酸甜菜碱(SBMA),制备无机复合纳米材料SBMA@CNT。系统的考察了不同添加量的SBMA@CNT对PES/SBMA@CNT超滤膜的机械强度和抗污染性能的影响。研究表明:SBMA@CNT的加入显著提高了PES/SBMA@CNT超滤膜的抗污染性能。当SBMA@CNT添加量为1%时,PES/SBMA@CNT超滤膜具有最优异的抗污染性能,通量恢复率为98.89%,通量衰减率为37.73%。基于强制表面偏析制备具有抗污染性能的超滤膜。通过自由基接枝聚合的方法制备了含有疏水链段甲基丙烯酸丁酯(PBMA),亲水链段甲基丙烯酸聚乙二醇酯(PEGMA)和低表面能链段甲基丙烯酸六氟丁酯(PHFBM)的两亲性类嵌段共聚物PBMA-PEGMA-PHFBM。系统的考察了PBMA-PEGMA-PHFBM对PVDF/PBMA-PEGMA-PHFBM超滤膜表面化学组成、表面亲水性、表面能和抗污染性能的影响;以及不同的搅拌速度、操作压力和油浓度对膜抗污染性能的影响。研究表明,PVDF/PBMA-PEGMA-PHFBM超滤膜在低搅拌速度、高操作压力及高油浓度下,均表现出优异的抗污染性能,通量恢复率均高于90%。
[Abstract]:Functional ultrafiltration membrane has a good application prospect in the fields of water treatment, biological separation, drug release control and so on.At present, the methods of designing and preparing functional ultrafiltration membrane mainly include surface grafting, surface coating, etc., which have the disadvantages of easily blocking membrane pores, complicated steps and high cost, which limit the development and application of functional ultrafiltration membrane.Surface segregation, as an in situ, three-dimensional modification method, can produce effective functional polymer brushes on the membrane surface.In this paper, functionalized ultrafiltration membranes were prepared based on surface segregation. The main work was as follows: the pH responsive ultrafiltration membranes were prepared based on free surface segregation.PMAAn-F127-PMAA, an amphiphilic block copolymer with different degree of graft polymerization, was grafted on Pluronic F127 molecule by free radical graft polymerization.The effects of degree of graft polymerization of PMAA chain on the surface chemical composition, surface hydrophilicity, surface charge and pH response of PES/PMAAn-F127-PMAAn ultrafiltration membrane were systematically investigated.With the increase of PMAA surface coverage, the pH responsiveness of the membrane increased.UF membranes with anti-pollution properties were prepared based on free surface segregation.The inorganic composite nanocomposite SBMA / CNT was prepared by co-distillation of amphoteric ion betaine methacrylate sulfonate onto CNT wall.The effects of SBMA@CNT on the mechanical strength and antifouling performance of PES/SBMA@CNT ultrafiltration membrane were systematically investigated.The results showed that the antifouling performance of PES/SBMA@CNT ultrafiltration membrane was improved by adding the PES/SBMA@CNT.When the amount of SBMA@CNT added is 1, PES / SBMA @ CNT ultrafiltration membrane has the best antifouling performance, the flux recovery rate is 98.89, and the flux attenuation rate is 37.73.UF membranes with anti-pollution properties were prepared based on forced surface segregation.The effects of PBMA-PEGMA-PHFBM on the surface chemical composition, surface hydrophilicity, surface energy and antifouling performance of PVDF/PBMA-PEGMA-PHFBM ultrafiltration membrane were systematically investigated, as well as the effects of different stirring speed, operation pressure and oil concentration on the antifouling performance of the membrane.The results showed that PVDF / PEGMA-PHFBM ultrafiltration membrane exhibited excellent antifouling performance at low stirring rate, high operating pressure and high oil concentration, and the flux recovery rate was higher than 90%.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893

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