Dopamine Incorporated Forward Osmosis Membranes with High Structural Stability and Chlorine Resistance

Yi Wang,Shuaifei Zhao,Zongli Xie,Derrick Ng,Zhendong Fang,Chaoxin Xie

doi:10.3390/pr6090151

Abstract

The degradation and detachment of the polyamide (PA) layer for the conventional thin-film composite (TFC) membranes due to chemical disinfectants cleaning with chlorine and material difference of PA layer and substrate are two major bottlenecks of forward osmosis (FO) technology. In this study, a new type of FO membranes was first prepared by controlling dopamine (DA) as the sole amine in the aqueous phase and the reaction with trimesoyl chloride (TMC) as the acyl chloride during interfacial polymerization (IP) process. The influence of membrane synthesis parameters such as monomer concentration, pH of the aqueous phase, IP reaction time and IP temperature were systematically investigated. The optimized membrane showed both improved structure stability and chlorine resistance, more so than the conventional TFC membrane. In general, novel DA/TMC TFC membranes could be an effective strategy to synthesize high-performance FO membranes with excellent structural stability and chlorine resistance.

Highlights

Forward osmosis (FO) has attracted increasing interest in seawater desalination [1,2,3], municipal sewage treatment [4,5], membrane bioreactors [6,7], agriculture fertilizers [8,9] and power generation [10,11], as a potential energy-saving and promising technology [12]
DA/trimesoyl chloride (TMC) thin-film composite (TFC) membranes possesses novel dense and thin active layers on top of the substrates, which are critical for high FO water flux and membrane selectivity [32]
Apart from the bands of the PSf substrates, the DA/TMC TFC series membranes showed enhanced peaks at 1660 cm−1 at the same time additional peaks at 1750 cm−1, which are attributed to the C=O breathing in the obtained amide bonds and the

Summary

Introduction

FO has attracted increasing interest in seawater desalination [1,2,3], municipal sewage treatment [4,5], membrane bioreactors [6,7], agriculture fertilizers [8,9] and power generation [10,11], as a potential energy-saving and promising technology [12]. Thin-film composite polyamide (TFC-PA) membranes, which consist of ultra-thin and dense polyamide (PA) layers and porous and thick substrate layers, have been studied for their applications in FO process due to their high salt rejection capability, wide range pH stability and independently modifiable support layer and active layer ability [13,14,15,16]. The thin and dense polyamide (PA) layer is synthesized by a interfacial polymerization process onto the substrate layer by two different monomers with amine and acyl chloride [17]. If the conventional TFC-PA membranes are used in some wastewater containing ethanol, the active PA layer could be detached from the top of the substrate layer, because there is no strong linkage

Methods

Results

Conclusion