Zwitterionic Polymer Brush Grafted on Polyvinylidene Difluoride Membrane Promoting Enhanced Ultrafiltration Performance with Augmented Antifouling Property

Superhydrophilic zwitterions on the membrane surface have been widely exploited to improve antifouling properties. However, the problematic formation of a <20 nm zwitterionic layer on the hydrophilic surface remains a challenge in wastewater treatment. In this work, we focused on the energy consumption and time control of polymerization and improved the strong hydrophilicity of the modified polyvinylidene difluoride (PVDF) membrane. The sulfobetaine methacrylate (SBMA) monomer was treated with UV-light through polymerization on the PVDF membrane at a variable time interval of 30 to 300 s to grow a poly-SBMA (PSBMA) chain and improve the membrane hydrophilicity. We examined the physiochemical properties of as-prepared PVDF and PVDF–PSBMAx using numeric analytical tools. Then, the zwitterionic polymer with controlled performance was grafted onto the SBMA through UV-light treatment to improve its antifouling properties. The PVDF–PSBMA120s modified membrane exhibited a greater flux rate and indicated bovine serum albumin (BSA) rejection performance. PVDF–PSBMA120s and unmodified PVDF membranes were examined for their antifouling performance using up to three cycles dynamic test using BSA as foulant. The PVDF-modified PSBMA polymer improved the antifouling properties in this experiment. Overall, the resulting membrane demonstrated an enhancement in the hydrophilicity and permeability of the membrane and simultaneously augmented its antifouling properties.

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Engineered Nanoparticles with Decoupled Photocatalysis and Wettability for Membrane-Based Desalination and Separation of Oil-Saline Water Mixtures

Nanomaterials ◽

10.3390/nano11061397 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1397

Author(s):

Bishwash Shrestha ◽

Mohammadamin Ezazi ◽

Gibum Kwon

Keyword(s):

Membrane Fouling ◽

Municipal Wastewater ◽

Uv Light ◽

Saline Water ◽

Membrane Surface ◽

Sio2 Nanoparticles ◽

Engineered Nanoparticles ◽

Water Mixture ◽

Organic Substances ◽

Suspended Substances

Membrane-based separation technologies are the cornerstone of remediating unconventional water sources, including brackish and industrial or municipal wastewater, as they are relatively energy-efficient and versatile. However, membrane fouling by dissolved and suspended substances in the feed stream remains a primary challenge that currently prevents these membranes from being used in real practices. Thus, we directly address this challenge by applying a superhydrophilic and oleophobic coating to a commercial membrane surface which can be utilized to separate and desalinate an oil and saline water mixture, in addition to photocatalytically degrading the organic substances. We fabricated the photocatalytic membrane by coating a commercial membrane with an ultraviolet (UV) light-curable adhesive. Then, we sprayed it with a mixture of photocatalytic nitrogen-doped titania (N-TiO2) and perfluoro silane-grafted silica (F-SiO2) nanoparticles. The membrane was placed under a UV light, which resulted in a chemically heterogeneous surface with intercalating high and low surface energy regions (i.e., N-TiO2 and F-SiO2, respectively) that were securely bound to the commercial membrane surface. We demonstrated that the coated membrane could be utilized for continuous separation and desalination of an oil–saline water mixture and for simultaneous photocatalytic degradation of the organic substances adsorbed on the membrane surface upon visible light irradiation.

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Preparation of alkali-resistant PVDF membranes via immobilization of sodium lauryl sulfate (SDS) on surface

Applied Water Science ◽

10.1007/s13201-021-01377-6 ◽

2021 ◽

Vol 11 (3) ◽

Author(s):

Gongpu Wen ◽

Kun Chen ◽

Yanhong Zhang ◽

Yue Zhou ◽

Jun Pan ◽

...

Keyword(s):

Sodium Lauryl Sulfate ◽

Alkali Treatment ◽

Membrane Surface ◽

Alkali Resistance ◽

Lauryl Sulfate ◽

Uv Curable ◽

Pvdf Membrane ◽

Glycol Diacrylate ◽

Polyester Acrylate ◽

Uv Curable Resin

AbstractA novel strategy was proposed to fabricate alkali-resistant PVDF membrane via sodium lauryl sulfate (SDS) attached to the surface of membrane and immobilized by UV-curable polyester acrylate and tri(propylene glycol) diacrylate (TPGDA). The attached anionic surfactant, SDS, on the membrane surface can resist the alkali corrosion by NaOH, and the curing of the resin can immobilize the SDS on the membrane firmly. Due to the unique alkali resistance of SDS and resin formed, the UV-curable resin-modified PVDF membrane showed greatly enhanced alkali-resistant ability. Characterization of SEM and FTIR showed that polyester acrylate and TPGDA were cured successfully under the action of 1-hydroxycyclohexyl phenyl ketone (184) and ultraviolet light. Whiteness, differential scanning calorimeter and X-ray photoelectron spectrometer characterization showed that the modified PVDF membrane had a lower degree of dehydrofluorination than the pristine PVDF membrane after alkali treatment. Results of the detailed alkali-resistant analysis indicated that the F/C ratio of the UV-curable resin-modified PVDF membrane decreased by 2.6% after alkali treatment compared to pristine PVDF membrane decreased by 19.28%. The alkali-resistant performance was mainly attributed to the immobilized SDS. This study provided a facile and scalable method for designing alkali-resistant PVDF membrane, which shows a promising potential in the treatment of alkaline wastewater and alkaline-cleaning PVDF membrane.

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P4VP Modified Zwitterionic Polymer for the Preparation of Antifouling Functionalized Surfaces

Nanomaterials ◽

10.3390/nano9050706 ◽

2019 ◽

Vol 9 (5) ◽

pp. 706 ◽

Cited By ~ 5

Author(s):

Chaoqun Wu ◽

Yudan Zhou ◽

Haitao Wang ◽

Jianhua Hu

Keyword(s):

Photoelectron Spectroscopy ◽

Cell Attachment ◽

Raft Polymerization ◽

Polymer Brush ◽

Contact Angles ◽

Polymerization Process ◽

Water Contact ◽

Zwitterionic Polymers ◽

Ito Glass ◽

Zwitterionic Polymer

Zwitterionic polymers are suitable for replacing poly(ethylene glycol) (PEG) polymers because of their better antifouling properties, but zwitterionic polymers have poor mechanical properties, strong water absorption, and their homopolymers should not be used directly. To solve these problems, a reversible-addition fragmentation chain transfer (RAFT) polymerization process was used to prepare copolymers comprised of zwitterionic side chains that were attached to an ITO glass substrate using spin-casting. The presence of 4-vinylpyridine (4VP) and zwitterion chains on these polymer-coated ITO surfaces was confirmed using 1H NMR, FTIR, and GPC analyses, with successful surface functionalization confirmed using water contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) studies. Changes in water contact angles and C/O ratios (XPS) analysis demonstrated that the functionalization of these polymers with β-propiolactone resulted in hydrophilic mixed 4VP/zwitterionic polymers. Protein adsorption and cell attachment assays were used to optimize the ratio of the zwitterionic component to maximize the antifouling properties of the polymer brush surface. This work demonstrated that the antifouling surface coatings could be readily prepared using a “P4VP-modified” method, that is, the functionality of P4VP to modify the prepared zwitterionic polymer. We believe these materials are likely to be useful for the preparation of biomaterials for biosensing and diagnostic applications.

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Hydrophylicity Enhancement of Modified Cellulose Acetate Membrane to Improve the Membrane Performance in Produced Water Treatment

MATEC Web of Conferences ◽

10.1051/matecconf/201815608003 ◽

2018 ◽

Vol 156 ◽

pp. 08003 ◽

Cited By ~ 1

Author(s):

Tutuk Djoko Kusworo ◽

Danny Soetrisnanto ◽

Cynthia Santoso ◽

Tyas Dwi Payanti ◽

Dani Puji Utomo

Keyword(s):

Water Treatment ◽

Produced Water ◽

Uv Light ◽

Light Exposure ◽

Membrane Surface ◽

Asymmetric Structure ◽

Dense Layer ◽

Cellulose Acetate Membrane ◽

Permeate Flux ◽

Produced Water Treatment

Produced water is a wastewater generated from petroleum industry with high concentration of pollutants such as Total Dissolved Solid, Organic content, and Oil and grease. Membrane technology has been currently applied for produced water treatment due to its efficiency, compact, mild and clean process. The main problem of produced water using membrane is fouling on the membrane surface which causes on low permeate productivity. This paper is majority focused on the improvement of anti-fouling performance through several modifications to increase CA membrane hydrophilicity. The membrane was prepared by formulating the dope solution consists of 18 wt-% CA polymer, acetone, and PEG additive (3 wt-%, 5 wt-%, and 7 wt-%). The membranes are casted using NIPS method and being irradiated under UV light exposure. The SEM images show that parepared membrane has asymmetric structure consist of dense layer, intermediete layer, and finger-like support layer. The filtration test shows that PEG addition increase the membrane hydrophilicity and the permeate flux increases. UV light exposure on the membrane improves the membrane stability and hydrophilicity. The imrpovement of membrane anti-fouling performance is essential to achieve the higher productivity without lowering its pollutants rejection.

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Zwitterionic polymer brush grafting on anodic aluminum oxide membranes by surface-initiated atom transfer radical polymerization

Polymer Chemistry ◽

10.1039/c7py00045f ◽

2017 ◽

Vol 8 (15) ◽

pp. 2309-2316 ◽

Cited By ~ 19

Author(s):

Chien-Wei Chu ◽

Yuji Higaki ◽

Chao-Hung Cheng ◽

Ming-Hsiang Cheng ◽

Chun-Wei Chang ◽

...

Keyword(s):

Aluminum Oxide ◽

Atom Transfer Radical Polymerization ◽

Radical Polymerization ◽

Anodic Aluminum Oxide ◽

Polymer Brush ◽

Atom Transfer ◽

Geometric Effect ◽

Anodic Aluminum ◽

Zwitterionic Polymer ◽

Oxide Membranes

A feasible processing of zwitterionic polymer-grafted anodic aluminum oxide (AAO) membranes by surface-initiated atom transfer radical polymerization (SI-ATRP) and the geometric effect were investigated.

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A nonionic polymer-brush-grafted PVDF membrane to analyse fouling during the filtration of oil/water emulsions

Journal of Membrane Science ◽

10.1016/j.memsci.2021.119644 ◽

2021 ◽

pp. 119644

Author(s):

Yang He ◽

Kexin Xu ◽

Xia Feng ◽

Li Chen ◽

Zhongyi Jiang

Keyword(s):

Polymer Brush ◽

Pvdf Membrane ◽

Nonionic Polymer ◽

Oil Water

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Polypyrrole vapor phase polymerization on PVDF membrane surface for conductive membrane preparation and fouling mitigation

Journal of Chemical Technology & Biotechnology ◽

10.1002/jctb.5416 ◽

2017 ◽

Vol 93 (3) ◽

pp. 683-689 ◽

Cited By ~ 8

Author(s):

Jiadong Liu ◽

Chang Tian ◽

Jingxue Xiong ◽

Bo Gao ◽

Shaonan Dong ◽

...

Keyword(s):

Vapor Phase ◽

Membrane Surface ◽

Membrane Preparation ◽

Pvdf Membrane ◽

Fouling Mitigation ◽

Conductive Membrane ◽

Vapor Phase Polymerization

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The Modification of PVDF Membrane via Crosslinking with Chitosan and Glutaraldehyde as the Crosslinking Agent

Indonesian Journal of Chemistry ◽

10.22146/ijc.25127 ◽

2018 ◽

Vol 18 (1) ◽

pp. 1

Author(s):

Romaya Sitha Silitonga ◽

Nurul Widiastuti ◽

Juhana Jaafar ◽

Ahmad Fauzi Ismail ◽

Muhammad Nidzhom Zainol Abidin ◽

...

Keyword(s):

Contact Angle ◽

Vinylidene Fluoride ◽

Membrane Surface ◽

Pure Water ◽

Water Flux ◽

Crosslinking Agent ◽

Hydrophobic Properties ◽

Pvdf Membrane ◽

Pure Water Flux ◽

Modified Membrane

Poly(vinylidene fluoride) (PVDF) has outstanding properties such as high thermal stability, resistance to acid solvents and good mechanical strength. Due to its properties, PVDF is widely used as a membrane matrix. However, PVDF membrane is hydrophobic properties, so as for specific applications, the surface of membrane needs to be modified to become hydrophilic. This research aims to modify PVDF membrane surface with chitosan and glutaraldehyde as a crosslinker agent. The FTIR spectra showed that the modified membrane has a peak at 1655 cm-1, indicating the imine group (–N=C)- that was formed due to the crosslink between amine group from chitosan and aldehyde group from glutaraldehyde. Results showed that the contact angle of the modified membrane decreases to 77.22° indicated that the membrane hydrophilic properties (< 90°) were enhanced. Prior to the modification, the contact angle of the PVDF membrane was 90.24°, which shows hydrophobic properties (> 90°). The results of porosity, Ɛ (%) for unmodified PVDF membrane was 55.39%, while the modified PVDF membrane has a porosity of 81.99%. Similarly, by modifying the PVDF membrane, pure water flux increased from 0.9867 L/m2h to 1.1253 L/m2h. The enhancement of porosity and pure water flux for the modified PVDF membrane was due to the improved surface hydrophilicity of PVDF membrane.

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Characterization of the Initial Fouling Layer on the Membrane Surface in a Membrane Bioreactor: Effects of Permeation Drag

Membranes ◽

10.3390/membranes9090121 ◽

2019 ◽

Vol 9 (9) ◽

pp. 121

Author(s):

Shengli Wang ◽

Xin Lu ◽

Lanhe Zhang ◽

Jingbo Guo ◽

Haifeng Zhang

Keyword(s):

Zeta Potential ◽

Electron Donor ◽

Energy Barrier ◽

Polyvinylidene Fluoride ◽

Membrane Bioreactor ◽

Membrane Surface ◽

Permeate Flux ◽

Pvdf Membrane ◽

Operating Modes

In this study, the properties of the initial fouling layer on the membrane surface of a bioreactor were investigated under different operating modes (with or without permeate flux) to improve the understanding of the effect of permeation drag on the formation of the initial fouling layer. It was found that protein was the major component in the two types of initial fouling layers, and that the permeation drag enhanced the tryptophan protein-like substances. The attraction of the initial foulants to the polyvinylidene fluoride (PVDF) membrane was ascribed to the high zeta potential and electron donor component (γ−) of the membrane. Thermodynamic analyses showed that the permeation drag-induced fouling layer possessed high hydrophobicity and low γ−. Due to permeation drag, a portion of the foulants overcame an energy barrier before they contacted the membrane surface, which itself possessed a higher fouling propensity. A declining trend of the cohesive strength among the foulants was found with the increasing development of both fouling layers.

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