Mimicking the cell membrane: bio-inspired simultaneous functions with monovalent anion selectivity and antifouling properties of anion exchange membrane.

Yan Zhao,Bart Van Der Bruggen,Jiefeng Pan,Kaini Tang,Congjie Gao,Jiangnan Shen,Huimin Liu,Yali Jin

doi:10.1038/srep37285

Yan Zhao, Bart Van Der Bruggen + Show 6 more

Open Access

https://doi.org/10.1038/srep37285

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Journal: Scientific reports	Publication Date: Nov 17, 2016
Citations: 32	License type: CC BY 4.0

Affiliation: KU Leuven, Zhejiang University of Technology

Abstract

A new bio-inspired method was applied in this study to simultaneously improve the monovalent anion selectivity and antifouling properties of anion exchange membranes (AEMs). Three-layer architecture was developed by deposition of polydopamine (PDA) and electro-deposition of N-O-sulfonic acid benzyl chitosan (NSBC). The innermost and outermost layers were PDA with different deposition time. The middle layer was prepared by NSBC. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that PDA and NSBC were successfully modified on the surfaces of AEMs. The contact angle of the membranes indicated an improved hydrophilicity of the modified membranes. A series of electrodialysis experiments in which Cl−/SO42− separation was studied, demonstrating the monovalent anion selectivity of the samples. The Cl−/SO42− permselectivity of the modified membranes can reach up to 2.20, higher than that of the commercial membrane (only 0.78) during 90 minutes in electrodialysis (ED). The increase value of the resistance of the membranes was also measured to evaluate the antifouling properties. Sodium dodecyl benzene sulfonate (SDBS) was used as the fouling material in the ED process and the membrane area resistance of modified membrane increase value of was only 0.08 Ωcm2 30 minutes later.

Highlights

In order to further characterize the modified membrane, the surface and cross-section of the anion exchange membranes (AEMs) were observed by scanning electron microscopy (SEM)
The architecture of the AEM composed of the membrane matrix and the bio-inspired architecture can be observed in these micrographs
Compared to the beginning of the membrane area reactance, we found the increase in the membrane area resistance was calculated according to

Summary

Introduction

Inspiring from the special “three-layer” structure of cell membrane to simultaneously improve monovalent anion selectivity and antifouling properties may break through this problem. When the keep same thickness of the NSBC layer as for membrane 3, but the innermost self-deposition of PDA at 2 hours (modified membrane 4), the area resistance is 1.87 Ωcm[2]. We attempted to simultaneously improve the antifouling property and the monovalent anion selectivity of AEM by inspiring the special “three-layer” structure modified membrane and the main materials were the PDA and NSBC.

Results

Conclusion