Ding Jincheng, Yang Shanshan, Pan Jiefeng, Zheng Yu, Sotto Arcadio, Shen Jiangnan
Center for Membrane Separation and Water Science & Technology, Ocean College, Zhejiang University of Technology Hangzhou 310014 P. R. China
Huzhou Institute of Collaborative Innovation Center for Membrane Separation and Water Treatment, Zhejiang University of Technology 1366 Hong Feng Road Huzhou Zhejiang 313000 China.
RSC Adv. 2018 Aug 29;8(53):30502-30511. doi: 10.1039/c8ra05152f. eCollection 2018 Aug 24.
The present study describes the synthesis of new nanofiltration membranes inspired by asymmetric porous membranes used as monovalent anion selective membranes for electro-membrane separation. The membrane surface was firstly modified, by deposition of a mussel-inspired "bio-glue" polydopamine (PDA) layer, and subsequently a compact polyamide layer was polymerized on the surface of the membrane's active layer. The chemical constitution and structure of these modified porous membranes were explored by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The surface roughness and hydrophilicity of the membranes were explored by atomic force microscopy (AFM) and water contact angle measurements, respectively. In addition, the electrochemical properties of the surface of the modified membranes were analyzed in terms of membrane surface resistance and zeta potential values. As for the performance of these modified porous membranes, this was investigated by measuring the permselectivity of a Cl/SO system. The obtained results show that the new membranes exhibit an enhanced monovalent anion permselectivity, which is in agreement with the improved membrane surface properties. Furthermore, membranes modified by the addition of a PDA layer and a dense polyamide active layer lead to a significant improvement in selectivity , compared with a conventional interfacial polymerization modified membrane . The excellent performance can be ascribed to the synergistic effect of the compact PDA layer and negatively charged interfacial polymerization layer, dependent on the sieving and electrostatic repulsion, respectively. Thus, this process is promising for the further development of porous monovalent selective anion exchange membranes.
本研究描述了受用作电膜分离单价阴离子选择性膜的不对称多孔膜启发而合成的新型纳滤膜。首先通过沉积受贻贝启发的“生物胶水”聚多巴胺（PDA）层对膜表面进行改性，随后在膜的活性层表面聚合一层致密的聚酰胺层。通过傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）对这些改性多孔膜的化学组成和结构进行了探究。分别通过原子力显微镜（AFM）和水接触角测量来探究膜的表面粗糙度和亲水性。此外，根据膜表面电阻和zeta电位值分析了改性膜表面的电化学性质。至于这些改性多孔膜的性能，通过测量Cl/SO体系的渗透选择性进行了研究。所得结果表明，新型膜表现出增强的单价阴离子渗透选择性，这与改善的膜表面性质一致。此外，与传统界面聚合改性膜相比，添加PDA层和致密聚酰胺活性层改性的膜在选择性方面有显著提高。优异的性能可归因于致密PDA层和带负电的界面聚合层的协同作用，分别取决于筛分和静电排斥。因此，该工艺对于多孔单价选择性阴离子交换膜的进一步发展具有前景。
