PEO改性PVDF_SMA膜结构和性能_杨园园.pdf

化工进展Chemical Industry and Engineering Progress2023 年第 42 卷第 3 期PEO改性PVDF/SMA膜结构和性能杨园园1，雷婷1，秦青青1，2，武晓1，3，李剑1，秦舒浩1，3，李嘉乐4，张兵兵1，任露露1（1贵州省材料产业技术研究院，贵州 贵阳 550025；2中国地质大学（北京）材料科学与工程学院，北京100083；3贵州大学材料与冶金学院，贵州 贵阳 550025；4贵州理工学院材料与能源工程学院，贵州 贵阳 550003）摘要：将聚氧化乙烯（PEO）添加到聚偏氟乙烯/苯乙烯马来酸酐树脂（PVDF/SMA）膜体系中，通过非溶剂致相分离法（NIPS）制备了添加不同PEO含量的PVDF/SMA共混膜。其中PEO质量分数为2%的共混超滤膜性能最好，水通量为531.1L/(m2h)，牛血清蛋白（BSA）截留率为65.8%，水接触角为63.6，膜剥离强度为0.2756kN/m。接着以PVDF/SMA膜为主要研究对象测试了凝固浴温度对共混超滤膜的纯水通量以及BSA截留率的影响，该实验的结果表明凝固浴温度的改变对膜性能没有产生明显的影响。因此，选择在常温凝固浴温度下测试不同凝固浴成分对共混膜性能的影响。探究了膜在凝固浴成分分别为N,N-二甲基乙酰胺（DMAc）（质量分数为3%、6%、9%）、氯化钠（NaCl）（0.05mol/L、0.1mol/L、0.2mol/L）和乙醇（质量分数为3%、6%、9%）时的膜性能变化，以及对各个组分得到的膜样本进行扫描电子显微镜（SEM）表征。结果表明，随着DMAc含量增加，膜表面的孔在减少，且膜皮层的厚度增加，使得膜的水通量减少而BSA截留率提高。而随着NaCl浓度的升高，共混膜表面的孔结构发生改变，孔数量增多，内部指状孔数量变多变窄，膜通量逐渐增大，BSA截留率降低。同样，随着凝固浴中乙醇含量的增加，膜表面孔数量增加，指状孔变窄孔壁增厚，共混膜的水通量有所提升，BSA截留率降低。总之，存在一个平衡点，采用合适的凝固浴成分和适量的浓度，可以显著提升共混膜部分性能。此外，膜的长期运行稳定性实验结果表明得到的共混膜具有较好的抗污染性和长期运行稳定性，在实际污水处理中具有良好的应用前景。关键词：聚氧化乙烯；聚偏氟乙烯；非溶剂致相分离法；凝固浴中图分类号：TQ028.8 文献标志码：A 文章编号：1000-6613（2023）03-1515-12Structure and properties of PEO modified PVDF/SMA membraneYANG Yuanyuan1，LEI Ting1，QIN Qingqing1，2，WU Xiao1，3，LI Jian1，QIN Shuhao1，3，LI Jiale4，ZHANG Bingbing1，REN Lulu1(1 Guizhou Material Industry Technology Research Institute,Guiyang 550025,Guizhou,China;2 School of Materials Science and Engineering,China University of Geosciences,Beijing 100083,China;3 College of Materials and Metallurgy,Guizhou University,Guiyang 550025,Guizhou,China;4 School of Materials and Energy Engineering,Guizhou Institute of Technology,Guiyang 550003,Guizhou,China)Abstract:In this study,polyethylene oxide(PEO)was added to poly(vinylidene fluoride)/styrene maleic anhydride copolymer(PVDF/SMA)membrane system,and PVDF/SMA blend membranes with different 研究开发DOI：10.16085/j.issn.1000-6613.2022-0869收稿日期：2022-05-10；修改稿日期：2022-08-17。基金项目：贵州省省级科技计划（黔科合支撑2020 4Y021号，黔科合服企20219号，黔科合支撑2022一般211号，黔科合基础2020 1Y183号，黔科合支撑2022一般057号）；贵阳市科技计划（筑科合同20211-1号）。第一作者：杨园园（1987），女，博士研究生，助理研究员，研究方向为膜分离技术。E-mail：。通信作者：秦舒浩，研究员，博士生导师，研究方向为聚合物共混改性。E-mail：。引用本文：杨园园,雷婷,秦青青,等.PEO改性PVDF/SMA膜结构和性能J.化工进展,2023,42(3):1515-1526.Citation：YANG Yuanyuan,LEI Ting,QIN Qingqing,et al.Structure and properties of PEO modified PVDF/SMA membraneJ.Chemical Industry and Engineering Progress,2023,42(3):1515-化工进展，2023，42（3）PEO contents were prepared by nonsolvent induced phase separation(NIPS).The results showed that the blend ultrafiltration membrane with PEO mass fraction of 2%had the best performance.Water flux was 531.1L/(m2h),BSA rejection rate was 65.8%,water contact angle was 63.6 and the peel strength was 0.2756kN/m.Then,PVDF/SMA membrane was used as the main research object to test the influence of coagulation bath temperature on pure water flux and BSA rejection rate.The results indicated that temperature had no obvious effect on membrane performance.Therefore,the effects of different coagulation bath components on the properties of blend films were tested at room temperature.The changes of membrane properties in coagulation bath with N,N-dimethylacetamide(DMAc)(mass fraction of 3%,6%,9%),sodium chloride(0.05mol/L,0.1mol/L,0.2mol/L)and ethanol(mass fraction of 3%,6%,9%)were investigated,and the membrane samples were characterized by scanning electron microscopy(SEM).The results showed that with the increase of DMAc content,the pores on the membrane surface decreased and the thickness of the cortex increased,resulting in the decrease of water flux and the increase of BSA rejection rate.However,with the increase of NaCl concentration,the number of macropores on the membrane surface increased and the number of finger shaped pores in the membrane became narrower,leading to the gradual increase of membrane flux and the decrease of BSA rejection.Similarly,with the increase of ethanol content in the coagulation bath,the number of pores on the membrane surface increased,the finger like pores narrowed and the pore wall thickened,the water flux of the blend membrane increased,and the BSA rejection decreased.In short,the use of appropriate coagulation bath ingredients and appropriate concentration can significantly improve the partial properties of the blended film.In addition,the experimental results of the long-term operation stability of the membrane showed that the blended membrane had good anti-fouling property and long-term operation stability,and had a good application prospect in practical sewage treatment.Keywords:PEO;PVDF;nonsolvent induced phase separation;coagulation bath膜分离技术是在20世纪初诞生、20世纪60年代后迅速崛起的一门新技术，是21世纪人类解决淡水匮乏和水污染最有效的方法之一1-2。膜分离技术通过终端过滤、减少化学药剂使用，在提高生活用水质量以及污染水再资源化的过程中，具有不可替代的优势3。膜材料决定膜的性能和成本，因此膜材料的研究在膜技术的发展中占据着不可分割的核心地位。在众多膜材料之中，聚偏氟乙烯（PVDF）以它优越的力学性能和化学性能常常被应用于污水处理分离膜研制之中。PVDF是一种具有较高机械强度、热稳定性高、耐腐蚀、耐氧化、易于成膜的优秀膜材料。但由于其表面能较低，无法同水分子形成氢键，因而制得的膜表面具有较高的疏水性，这导致纯PVDF膜在实际的污水分离处理应用中存在水通量低和容易受到污染等缺陷，导致膜在使用过程中其性能逐渐下降，且使用周期缩短4-5。因此，PVDF的亲水改性对延长其在实际水处理中的使用寿命具有重大的研究意义。为改善膜的结构和性能，通常在铸膜液配方中加入其他可以改善膜亲水性的添加剂，对膜性能从物理或化学两个方面进行改性，从而调整膜结构和提高膜的亲水性、抗污染性以及长期稳定性，以延长膜的使用寿命。目前，对PVDF膜的改性方法主要