Antifouling performance of poly(lysine methacrylamide)-grafted PVDF microfiltration membrane for solute separation

Abstract

In this work, antifouling poly(vinylidene fluoride) (PVDF) microfiltration membrane was fabricated via surface activation by atmosphere plasma treatment and subsequently surface-initiated atom transfer radical polymerization (SI-ATRP). Zwitterionic poly(lysine methacrylamide) (LysAA) brushes were successfully grafted onto membrane surface as confirmed by Fourier-transform infrared spectrometer (FTIR) and X-ray photoelectron spectroscopy (XPS). The wetting ability of the graft membranes was improved significantly with water contact angle decreased from 121.6º to as low as 29.0º. The graft membranes also exhibited enhanced anti-protein-fouling and anti-oil-fouling properties with water flux recovery ratios as high as 86% and 82% respectively. This work provides a substrate-independent method for the fabrication of antifouling membranes with well-defined pLysAA brushes, which may find applications in protein separation, water treatment and oil/water separation, etc.

Antifouling membranes for oily wastewater treatment: Interplay between wetting and membrane fouling

“…There are various methods to improve the hydrophilicity of the membrane, including surface modification, blending and fabricating nanocomposite membranes. [17,23,30,32,52,54,57,59,72,74,75,77,80,90,97,98,[106][107][108][109][110][111][112][113] Surface hydrophilization. The surface hydrophilicity of a membrane can be increased by surface modification, e.g., introducing hydrophilic polymers or nanoparticles on the membrane surface.…”

“…[32] Surface grafting requires functional groups on the membrane surface, so that the hydrophilic polymers with reactive groups can be grafted to it via formation of chemical bonds. [30,54,74] In comparison, surface coating does not require functional groups on the membrane, [17,52,57,72,75,80,[107][108][109][110]114] and the polymers are coated on the membrane by strong physical adsorption. The stability of the coating can be further improved by crosslinking.…”

Antifouling poly(vinylidene fluoride) hollow fiber membrane with hydrophilic surfaces by ultrasonic wave‐assisted graft polymerization

“…With the increasing graft density, the pore size tends to be more uniform, the ratio of large pore size and the amount of pores gradually reduced. When the GD was 2.76 mg/cm 2 (M3), the pore sizes of the membrane surface were mainly distributed in the range of 0–0.2 μm and the large pores were almost completely covered, which due to the coverage of the grafted chains and the formation of a dense PAA layer on the membrane surface. And the SEM images of cross‐sections of the pristine and modified membranes were shown in Fig.…”

“…As one of the most popular membrane materials, poly(vinylidene fluoride) (PVDF) has been widely used in environmental management, electronics, medicine, gas separation, and biotechnology due to its superior chemical stability, thermal stability, mechanical properties, and ease of film formation . However, because of its intrinsic hydrophobicity and low surface energy, PVDF hollow fiber membrane has two problems in the treatment of water‐based fluids : (1) It is easy to adsorb organic pollutants, causing pore clogging and the layers of contaminants; (2) Organic pollutants provide living conditions to adherent microorganisms, gradually forming irreversible pollution.…”

Super‐hydrophilic electrospun PVDF/PVA‐blended nanofiber membrane for microfiltration with ultrahigh water flux

“…Antifouling capabilities of the pristine PVDF and PVDF/PVA‐blended membranes need to be further compared, and three parameters are used to evaluate the fouling resistance. The total fouling ratio ( R t ) includes the reversible fouling ratio ( R r ) and the irreversible fouling ratio ( R ir ) . Among them, reversible fouling can be removed by rinsing with pure water, but irreversible fouling cannot be removed by the same operation.…”