Improved antifouling properties of PVDF membranes modified with oppositely charged copolymer

Abstract

Biofouling resulting from the attachment of microorganisms communities to the membrane surface is the major obstacle for the widespread application of membrane technology. This work develops a feasible approach to prepare an anti-biofouling poly(vinylidene fluoride) (PVDF) membrane. A copolymer that possessed oppositely charged groups was first synthesized via radical copolymerization with methyl methacrylate, 2-methacryloxy ethyltrimethyl ammonium chloride and 2-acrylamide-2-methyl propane sulphonic acid as monomers. The copolymer was blended with the PVDF powder to prepare the antifouling membrane via the immersed phase inversion method. The antifouling properties of the modified PVDF membrane were studied by X-ray photoelectron spectroscopy, field emission scanning electron microscopy, water contact angle measurement, zeta-potential measurement, protein adsorption, microbial adhesion and filtration experiments. The modified PVDF membrane showed limited adsorption and adhesion of protein bovine serum albumin and microbes (Escherichia coli and Saccharomyces cerevisiae) with increasing copolymer concentration in the casting solution. The modified PVDF membrane exhibited excellent antibiofouling properties.

Antifouling enhancement of PVDF membrane tethered with polyampholyte hydrogel layers

“…In addition, a faster decay rate of contact angle can be observed on the modified membranes surface than pristine PVDF membrane. When a water drop contacts the membrane surface, the instant spread of water drop was driven by the electrostatic interactions between charged groups and water molecules . These results indicate that the polyampholyte hydrogel layers have enhanced the surface hydrophilicity of PVDF membrane.…”

Preliminary investigation on hemocompatibility of poly(vinylidene fluoride) membrane grafted with acryloylmorpholine via ATRP

“…Two possible reasons may be related to the change in the membrane permeability. One is the increase in hydrophilicity of membrane due to the introduction of ACMO, and the other is the formation of a porous membrane structure with a large pore size . During the filtration process, the improved hydrophilicity inhibits the deposition of BSA protein, preventing the membrane pore blockage.…”

“…Nevertheless, the ether bonds within the PEGMA chains are easily oxidized to reactive aldehyde moieties, especially in the presence of oxygen and transition metal ions typically found in biological media . In addition, to incorporate the highly polar zwitterionic polymer into the PVDF membrane is difficult because of their incompatibility . The immobilization of these hydrophilic layers on the existing hydrophobic membrane surface has various disadvantages, such as the reduced permeability caused by the pore blockage, and non‐uniform distribution of grafting layers on the membrane surface or the pore surface .…”

Dual functionalized poly(vinylidene fluoride) membrane with acryloylmorpholine and argatroban to improve antifouling and hemocompatibility

“…Fortunately, chemical modification can be realized by material and surface modification to overcome such shortcomings. The two most common modifiers are poly(ethylene glycol) (PEG) and zwitterionic polymers . Although the modified membranes have improved resistance to nonspecific protein adsorption and possess excellent resistance to platelet adhesion, some limitations exist.…”