Full Length ArticleImproved antifouling performance of ultrafiltration membrane via preparing novel zwitterionic polyimide
Graphical abstract
Introduction
Nowadays, there are several problems worldwide associated with water pollution, energy shortages and environmental challenges. Membrane technology, especially ultrafiltration (UF), can solve these problems mentioned above since it involves a number of attractive advantages including low energy consumption, competitive operating cost, mild operating condition, unique separation principle and transport selectivity, high separation efficiency and its environmentally benignity [1]. Ultrafiltration has gained an important place and made great progress in numerous industries and used in a broad range of applications, particularly in wastewater treatment. Membrane material is the decisive factor for determining various membrane properties, such as hydrophilicity, morphology, surface charge and allowable pH range, which gives a direct influence on membrane performance including permeability and selectivity as well. Ultrafiltration fueling this progress and obtaining the high efficiency are urgent need to meet the growing demand for high performance membrane materials. To date, ultrafiltration membranes have made from a wide variety of chemically and thermally stable synthetic polymers, including polyvinyl chloride (PVC), polyacrylonitrile (PAN), polysulfone (PSf), polyethersulfone (PES), polyimides (PIs) and polyvinylidene fluoride (PVDF) [2]. However, these membrane materials are not ideal candidates due to their inherent hydrophobic properties, which restrict the permeate flux in aqueous phase system and result in serious membrane fouling [3]. In particular, membrane fouling is a major obstacle to the widespread use of membrane technology, which can cause severe flux decline and affect productivity, alter membrane selectivity, shorten membrane life, require intense chemical cleaning or frequent membrane replacement, and significantly enhance the operating cost by increasing osmotic pressure and circulating the feed solution [4], [5], [6]. Therefore, much attention has been attracted to preparing and modifying membrane materials with tailorable chemical structures or groups in an attempt to improve their antifouling performance [7], especially the recent development of zwitterionic membrane materials [8].
Zwitterionic polymers, containing typically the same number of anionic and cationic groups, and the overall charge is zero under normal condition despite the high density of ion pairs attached to the polymer backbones, which are particularly attractive as a promising alternative to pave the way for antifouling ultrafiltration membrane [9]. In general, the chemical structures of zwitterionic polymers are commonly hydrophilic, overall electrically neutral, hydrogen-bond acceptors but not hydrogen-bond donors [10], [11]. Due to these unique characteristics, zwitterionic polymers can form the hydration layer near the membrane surface to avoid the adsorption of solutes and confer to various materials excellent biocompatibility and resistance to nonspecific protein adsorption, bacterial adhesion, and (bio)fouling [12]. Recently, much effort had been given to preparing zwitterionic-based ultrafiltration membrane by two strategies primarily including surface grafting or coating of zwitterionic polymers after membrane preparation (surface modification method) [13], [14], [15] and synthesis of novel zwitterionic polymers before membrane preparation (chemical synthesis method) [16]. The former has narrow potential window for large-scale application since surface grafting and coating involve complicated preparation process and limited production, as well as often block the membrane pores and suffer flux reduction, all the reported applications of zwitterionic surface are still at experimental stage [13], [17]. There is thereby an urgent need but it is still a significant challenge to the development of zwitterionic surface. In contrast, the future looks bright for incorporating zwitterionic structure and high performance synthetic polymer into a single membrane material by the chemical synthesis method to facile and large-scale fabricate the desired antifouling ultrafiltration membrane through conventional phase inversion method, which is regarded as an efficient way to promote the development of membrane technology. Currently, numerous significant researches had exploited different types of zwitterionic polymer membrane material with superior antifouling property and high permeability, such as zwitterionic chitosan [18], zwitterionic cellulose acetate [19], zwitterionic polyvinyl chloride [20], polyacrylonitrile-based zwitterionic copolymers (PAN-DMAEMA, PAN-DMMSA and PAN-MPDSAH) [21], [22], [23], polymethylmethacrylate-based zwitterionic copolymers (P(MMA-co-SBVIM)and P(MMA-co-CBVIM)) [24], zwitterionic tertiary amine modified polyethersulfone [25], zwitterionic sulfobetaine poly(arylene ether sulfone) (PES-SB) and carboxybetaine poly(arylene ether sulfone) (PES-CB) [26], etc. However, achieving excellent antifouling property and separation performance of membrane materials, while retaining their thermal and chemical stability, remains a challenge.
Polyimides (PIs) are a class of high performance engineering plastics and composed of aromatic dianhydride and diamine monomers. Due to excellent thermal and dimensional stability, chemical resistance, and mechanical strength, polyimides can meet a number of key requirements for ideal membrane materials [27]. However, their inherent hydrophobicity raises serious concerns over insufficient wettability, which could directly impair permeability and antifouling property of the liquid filtration membrane. Owing to the multiple possible synthetic approaches and various available dianhydride and diamine monomers, a wide variety of polyimides with desired chemical structures can be prepared by an accurate molecular design and functionalized with respect to the applicative purposes [28]. It is expected that zwitterionic polyimide provide a good approach to improve permeability and antifouling property of ultrafiltration membrane. Zwitterionic polymers are commonly prepared using free radical polymerization and ring opening of lactone [12], [29]. In this study, zwitterionic polyimide (Z-PI) was successfully synthesized by employing a two-step procedure consist of polycondensation and quaternary amination reaction. Z-PI was then extensively characterized in terms of chemical structure, chemical composition, thermal stability and solubility behavior. Subsequently, the hydrophilicity, morphology and pore statistic of Z-PI membrane were thoroughly studied, and the protein static adsorption of Z-PI membrane was examined to provide a better understanding of the effect of zwitterionic groups on membrane antifouling performance. Furthermore, the protein separation and long-term performance stability of Z-PI membrane were investigated by dynamic cycling ultrafiltration experiment and the results were compared in detail with those obtained by using the reference polyimide (R-PI) membrane.
Section snippets
Materials
4,4′-Diamino-4′′-(dimethylamino)triphenylamine (TPA-NMe2) was synthesized according to a previously reported procedure [30]. 4,4′-Oxydiphthalic dianhydride (ODPA) was purchased from Tokyo Chemical Industry (TCI, Japan) and purified by recrystallization from acetic anhydride. 4,4′-diaminodiphenyl ether (ODA), polyethyleneglycol (PEG) with a molecular weight of 400 Da, sodium bromoacetate (SBA), isoquinoline and m-cresol were purchased from Aladdin Reagent (China). Dimethyl sulfoxide (DMSO) was
Characterization of zwitterionic polyimide
The polymer preparation processes are outlined in Scheme 1, the polyimide bearing pendant tertiary amine groups (TA-PI) was synthesized by a one-pot, high-temperature polycondensation of TPA-NMe2 and ODPA in the m-cresol/isoquinoline system. Then, TA-PI was converted to zwitterionic polyimide (Z-PI) by quaternary amination reaction, and the mole ratio of SBA to the tertiary amine group was set to 2:1 to ensure complete conversion of the tertiary amine group into zwitterionic group. For the
Conclusions
In this work, a novel zwitterionic polyimide (Z-PI) membrane material was successfully synthesized by solution polycondensation and quaternary amination reaction, which was confirmed by FTIR, 1H NMR and XPS measurements. Subsequently, Z-PI membrane was prepared via phase inversion induced by immersion precipitation method, which processed several advantages such as high hydrophilic, high water permeation property, excellent fouling resistant ability and performance stability. Furthermore, the
Acknowledgements
This work is financially supported by the Fundamental Research Funds for the Central Universities (No. 2572016BB03), Youths Science Foundation of Heilongjiang Province, China (No. QC2014C044), and National Innovation Training Program for Undergraduates of Northeast Forestry University (201710225051).
References (42)
- et al.
Status after 10 years of operation—overview of UF technology today
Desalination
(2000) Advanced functional polymer membranes
Polymer
(2006)- et al.
Application and modification of poly (vinylidene fluoride) (pvdf) membranes—a review
J. Membr. Sci.
(2014) - et al.
Membrane fouling control in ultrafiltration technology for drinking water production: a review
Desalination
(2011) - et al.
Irreversible membrane fouling during ultrafiltration of surface water
Water Res.
(2004) - et al.
Preparation of hydrophilic and antifouling polysulfone ultrafiltration membrane derived from phenolphthalin by copolymerization method
Appl. Surf. Sci.
(2017) - et al.
Modification of polyethersulfone membranes—a review of methods
Prog. Mater. Sci.
(2013) - et al.
Polyacrylonitrile-based zwitterionic ultrafiltration membrane with improved anti-protein-fouling capacity
Appl. Surf. Sci.
(2014) - et al.
Surface modification of cellulose membranes with zwitterionic polymers for resistance to protein adsorption and platelet adhesion
J. Membr. Sci.
(2010) - et al.
The preparation of antifouling ultrafiltration membrane by surface grafting zwitterionic polymer onto poly(arylene ether sulfone) containing hydroxyl groups membrane
Desalination
(2013)
Preparation of PES ultrafiltration membranes with natural amino acids based zwitterionic antifouling surfaces
Appl. Surf. Sci.
K. Schroëna, Modification methods for poly(arylsulfone) membranes: a mini-review focusing on surface modification
Desalination
Exploration of zwitterionic cellulose acetate antifouling ultrafiltration membrane for bovine serum albumin (BSA) separation
Carbohyd. Polym.
Zwitterionic ultrafiltration membranes for As (V) rejection
Chem. Eng. J.
Improved antifouling property of zwitterionic ultrafiltration membrane composed of acrylonitrile and sulfobetaine copolymer
J. Membr. Sci.
Controlled adsorption of bovine serum albumin on poly(acrylonitrile)-based zwitterionic membranes
React. Funct. Polym.
Highly efficient antifouling ultrafiltration membranes incorporating zwitterionic poly([3-(methacryloylamino)propyl]-dimethyl(3-sulfopropyl) ammonium hydroxide)
J. Membr. Sci.
Ionic liquids as co-solvents for zwitterionic copolymers and the preparation of poly(vinylidene fluoride) blend membranes with dominated β-phase crystals
Polymer
Zwitterionic polyethersulfone ultrafiltration membrane with superior antifouling property
J. Membr. Sci.
Novel zwitterionic poly(arylene ether sulfone)s as antifouling membrane material
J. Membr. Sci.
The strategies of molecular architecture and modification of polyimide-based membranes for CO2 removal from natural gas—a review
Prog. Polym. Sci.
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H.T. Huang and J.Y. Yu contribute equally to this work.