膜科学与技术

聚乙烯醇/聚多巴胺-氮化碳渗透汽化复合膜的制备

作者：王杰，陈明，李梅生，周守勇，赵宜江，钟璟

单位： 1.淮阴师范学院化学化工学院，江苏省环境功能材料工程实验室，江苏淮安 223300；2. 常州大学石油化工学院，江苏常州 213164

关键词：渗透汽化脱水；水选择性；纳米复合膜；多巴胺改性氮化碳；聚乙烯醇

出版年,卷(期):页码： 2018,38(2):37-44

摘要：

采用多巴胺改性氮化碳(PDA@g-C3N4)添加到聚乙烯醇(PVA)中制备出具有优异的乙醇/水分离性能和水分子通道的高度选择性有机-无机杂化膜。通过扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)和X射线衍射(XRD)等对形成的超细纳米孔氮化碳结构进行表征。由于多巴胺(DA)、氮化碳、琥珀酸(Sa)和聚乙烯醇之间具有相互作用，使得纳米复合膜具有抗溶胀性和机械性能稳定性。此外，多巴胺改性氮化碳的加入，也可以进一步的提高膜的亲水性和热稳定性。杂化膜(CPVA-PDA@g-C3N4/PAN)的总渗透通量和分离因子可以达到3415 g/(m2h)和37.5，和交联的纯聚乙烯醇膜(CPVA) (通量和分离因子为2337 g/(m2h)和11.2)相比较而言，该膜可以同时有效的提高杂化膜的分离性能，也就是我们所说的打破了“trade-off”效应。对该膜的亲疏水性和机械强度进一步测试可知，膜的接触角下降到42.9°，拉伸强度达到了40.19 MPa，弹性模量为448.61 MPa。

Highly water-selective hybrid membranes with excellent water/ethanol separation performance and superior water channels were fabricated by incorporating polydopamine modified g-C3N4 nanosheets (PDA@g-C3N4) into a poly(vinyl alcohol) (PVA) matrix. Due to the strong interfacial interactions among dopamine (DA), g-C3N4, succinic acid (Sa) and the PVA matrix, the hybrid nanocomposite membranes showed both high swelling resistance and mechanical stability. Furthermore, the addition of PDA@g-C3N4 can significantly improve the membrane’s hydrophilicity and heat-resistance properties. Importantly, membrane permeability improved greatly because the ordered alignment and the regular pore structure of g-C3N4 resulted in ordered water channels for rapid transportation of water molecules. The total flux and separation factor of this new membrane can reach about 3415 g/(m2h), and 37.5 for 90% wt. % ethanol, respectively. Compared with the cross-linked pure PVA membrane (2337 g/(m2h) and 11.2), the flux and separation factor can be improved simultaneously. Namely, the composite membrane can break the “trade-off effect” effectively. The contact angle of the membrane was reduced to 42.9 °, the mechanical strength was reached up to 40.19 MPa, and the tensile modulus was 448.61 MPa, which was further tested by the hydrophobicity and mechanical strength of the membrane.

第一作者简介：王杰(1991-)，男，江苏淮安人，硕士研究生，从事分离膜制备与应用研究，Email：lhswj2013@sina.com 通讯联系人：李梅生（1980-），男，博士，副教授，Email：lms1108@hytc.edu.cn；赵宜江(1968-)，男，博士，教授，Email：cyjzhao@yahoo.com.

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