聚合物和纳米材料强化聚醚砜超滤膜性能研究

发布时间：2018-10-17 19:26

【摘要】：膜分离技术是一种高效、节能、环保、分子级过滤的分离新技术,兼有分离、浓缩、纯化和精制功能。而分离膜是膜过程的核心,新型高性能超滤膜的开发对膜技术应用拓展极为重要。超滤是膜分离技术的一个重要分支,在工业水处理、制药、食品加工和生活净水等领域发挥着重要作用。本文以研制高性能超滤膜为目的,应用聚合物、聚苯胺纳米复合材料(PANI-PVP)和二氧化钛纳米材料强化聚醚砜(PES)超滤膜的分离性能。实验以聚醚砜(PES)为膜材料,N,N-二甲基乙酰胺(DMAc)为溶剂,聚甲基丙烯酸甲酯(PMMA)、聚乙烯吡咯烷酮(PVP-58000)、聚乙二醇-聚丙二醇-聚乙二醇三嵌段共聚物(Pluronic F127)或乙酸乙烯酯与N-乙烯基吡咯烷酮的共聚物(P(vp-co-va)-50000)为添加剂,采用浸没沉淀相转化法制备聚醚砜复合超滤膜,考察添加剂的种类对膜性能的影响。结果表明,PMMA、PVP、Pluronic F127、P(vp-co-va)为添加剂制备的超滤膜都呈典型的不对称结构。聚合物添加剂的加入起到了明显的致孔作用,并改善了膜表面亲水性,改性复合膜的纯水通量得到明显提升,纯水通量可提高为PES膜的1.7-4.8倍,且BSA截留率均保持在96.7%以上。实验采用分散聚合法制备PANI-PVP8000、PANI-PVP58000纳米复合材料,同时还选择两种不同粒度的纳米二氧化钛TiO2(5-10 nm)和TiO2(25 nm)作为添加剂。分析比较四种纳米材料添加剂对成膜过程、膜结构和膜性能的影响。实验结果表明,纳米超滤膜的亲水性得到改善,其中PES/PANI-PVP8000-0.5膜的接触角降低至62.5°;改性纳米复合膜的纯水通量和BSA溶液通量均有较大提升,且膜对BSA截留率均能达到98.7%以上;改性膜具有更强的抗BSA污染性能。实验进一步使用P(vp-co-va)/PANI-PVP58000、P(vp-co-va)/TiO2(5-10 nm)、Plu/PANI-PVP58000、Plu/TiO2(5-10 nm)等混合添加剂改性PES超滤膜。通过对改性超滤膜表面结构与性质、选择透过性能的考察,发现混合添加纳米超滤膜的膜表面亲水性得到明显改善,其中PES/Plu-2.0/PANI-PVP58000-0.5膜表面接触角为63.1°。在0.20MPa下,聚合物纳米材料混合强化超滤膜的纯水通量为PES超滤膜的3.4-5.0倍,且对BSA的截留率保持在97.3%以上。
[Abstract]:Membrane separation technology is a new separation technology with high efficiency, energy saving, environmental protection and molecular filtration. It has the functions of separation, concentration, purification and purification. The separation membrane is the core of membrane process. The development of new high performance ultrafiltration membrane is very important to the application of membrane technology. Ultrafiltration is an important branch of membrane separation technology, which plays an important role in industrial water treatment, pharmaceutical, food processing and water purification. In this paper, polymer, Polyaniline nanocomposites (PANI-PVP) and titanium dioxide nanomaterials were used to enhance the separation performance of polyethersulfone (PES) ultrafiltration membrane. Polyethersulfone (PES) was used as the membrane material, and NN- dimethyl acetamide (DMAc) was used as solvent. Polymethyl methacrylate (PMMA),) polyvinylpyrrolidone (PVP-58000), poly (ethylene glycol) -poly (propylene glycol) -polyethylene glycol triblock copolymer (Pluronic F127) or vinyl acetate copolymer (P (vp-co-va) -50000) were used as additives. The polyether sulfone composite ultrafiltration membrane was prepared by immersion precipitation phase inversion method. The results showed that the ultrafiltration membranes prepared with PMMA,PVP,Pluronic F127 P (vp-co-va) as additives all showed a typical asymmetric structure. The addition of polymer additive can obviously induce pore and improve the hydrophilicity of the membrane surface. The pure water flux of the modified composite membrane is obviously increased, and the pure water flux can be increased by 1.7-4.8 times of that of the PES membrane, and the rejection rate of BSA is above 96.7%. PANI-PVP8000,PANI-PVP58000 nanocomposites were prepared by dispersion polymerization. Two kinds of nano-TiO _ 2 TiO2 (5-10 nm) and TiO2 (25 nm) were used as additives. The effects of four nano-materials additives on the film formation process, membrane structure and membrane properties were analyzed and compared. The results showed that the hydrophilicity of nanofiltration membrane was improved, the contact angle of PES/PANI-PVP8000-0.5 membrane was reduced to 62.5 掳, the pure water flux and BSA solution flux of modified nano-composite membrane were greatly improved, and the membrane rejection rate of BSA was above 98.7%. The modified membrane has stronger resistance to BSA pollution. The PES ultrafiltration membrane was further modified by P (vp-co-va) / PANI-PVP58000,P (vp-co-va) / TiO2 (5-10 nm), Plu/PANI-PVP58000,Plu/TiO2 (5-10 nm). By investigating the surface structure and properties of the modified ultrafiltration membrane, it was found that the surface hydrophilicity of the modified ultrafiltration membrane was obviously improved by adding nano-nano ultrafiltration membrane, and the surface contact angle of the PES/Plu-2.0/PANI-PVP58000-0.5 membrane was 63.1 掳. Under 0.20MPa, the pure water flux of polymer nanomaterials mixed enhanced ultrafiltration membrane was 3.4-5.0 times of that of PES ultrafiltration membrane, and the rejection rate of BSA was over 97.3%.
【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893

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