Hydrophilic and Positively Charged Polyvinylidene Fluoride Membranes for Water Treatment with Excellent Anti-Oil and Anti-Biocontamination Properties

Abstract

Membrane fouling limits the rapid development of membrane separations. In this study, a blend membrane containing polycationic liquid (P(BVImBr1-co-PEGMA1)) is presented that can improve the antifouling performance of polyvinylidene fluoride (PVDF) membranes. By mixing the polycationic liquid into PVDF, an improved membrane-surface hydrophilicity and enlarged membrane porosity were detected. The water contact angle decreased from 82° to 67°, the porosity enlarged from 7.22% to 89.74%, and the pure water flux improved from 0 to 631.68 L m−2 h−1. The blend membrane surfaces were found to be always positively charged at pH 3~10. By applying the membranes to the filtration of oil/water emulsion and bovine serum albumin (BSA) solution, they showed a very high rejection rate to pollutants in wastewater (99.4% to oil droplets and 85.6% to BSA). The positive membrane surface charge and the increased membrane hydrophilicity resulted in excellent antifouling performance, with the flux recovery rates of the dynamic filtration tests reaching 97.3% and 95.5%, respectively. Moreover, the blend membranes demonstrated very low BSA adhesion and could even kill S. aureus, showing excellent antifouling properties.

Preparation of a PVDF–PDA–DETA@PVP@HNT membrane for high efficiency oil–water emulsion separation

“…[11][12][13][14][15] Polymer materials commonly used for membrane separation include polyacrylonitrile (PAN), polyethersulfone (PES), polypropylene (PP), polyvinylidene fluoride (PVDF), and so on. [16][17][18][19][20] Among them, PVDF is one of the most popular and important polymers in industrial applications and research studies. PVDF membranes are widely used in microfiltration, ultrafiltration and wastewater treatment processes due to their excellent properties, including high thermal stability, mechanical stability and chemical resistance.…”

Ag-CuO-Decorated Ceramic Membranes for Effective Treatment of Oily Wastewater

“…Recently, membrane separation, especially ultrafiltration (UF), has been considered a more effective approach for the industrial processing of o/w emulsions because it is fast, simple, less energy-intensive, offers great flexibility for design scalability, avoids chemical additives, and reduces the oil concentration even below the acceptable regulatory discharge limit [ 9 , 10 , 11 ]. Therefore, much research is being done on the design and fabrication of o/w separation membranes [ 12 , 13 ]. Currently, polymeric membranes are the most widely used category of membranes due to their simple functionality, high porosity, and low cost.…”

Advanced Membrane Technologies for Wastewater Treatment and Recycling

“…Half of the published papers in this Special Issue focused on membrane fabrication and modification, with new strategies developed to improve membrane separation [ 1 , 2 , 3 , 4 ], permeability [ 5 , 6 , 7 ], and anti-fouling properties [ 8 , 9 ] by fabricating the membrane structure or surface properties. For example, Fang et al [ 1 ] fabricated a loose nanofiltration membrane by integrating blending and interfacial coordination strategies; this resulted in a membrane with good pure water flux, dye rejection, and salt penetration.…”

“…Liu et al [ 5 ] synthesized a covalent–organic framework (COF) composite membrane by assembling COF layers and the imidazole-quartet water channel, which exhibited excellent performance above 271.7 L m −2 h −1 bar −1 water permeance and above a 99.5% congo red rejection rate. Wang et al [ 9 ] improved the antifouling performance of this membrane by modifying the membrane surface hydrophilicity and porosity by mixing polycationic liquid into the polyvinylidene fluoride (PVDF) membrane.…”