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Polyvinylidene fluoride (PVDF) membranes have been widely applied in the separation of various organic matters owing to their excellent properties. However, they possess low wettability and undergo fouling because of the hydrophobic nature of PVDF. In this study, poly (2‐hydroxyethyl methacrylate) (PHEMA) and poly (sulfobetaine methacrylate) (PSBMA) were co‐introduced to modify the highly hydrophobic PVDF membrane surface via UV photo‐irradiation. Facile UV photo‐grafting was performed by irradiating the pristine PVDF membrane immersed in a PHEMA/PSBMA mixture solution with UV light for 5 min. The performance of the as‐prepared PHEMA/PSBMA‐grafted membrane was compared with that of membranes modified with solely PHEMA or PSBMA. The hydroxyl and zwitterionic groups of the grafted membranes enhanced wettability and increased flux. A tightly bound water layer was formed because of the enhanced wettability, significantly suppressing protein adsorption. The initial flux of bovine serum albumin (BSA) solution through the PHEMA/PSBMA‐grafted membrane was 2861 LMH, which was 3.1 times higher than that obtained by the pristine PVDF membrane. Furthermore, the flux decline of the modified membrane caused by BSA fouling was 49% lower than that of the pristine PVDF membrane. Finally, the PHEMA/PSBMA‐grafted PVDF membrane showed antifouling properties after three BSA filtration cycles. [ABSTRACT FROM AUTHOR]

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To enable the wide application of nanofiltration (NF) membranes to increase the fresh water supply, the development of new membrane materials and preparation techniques are still highly desired. In this work, thin-film composite (TFC) NF membranes were fabricated via interfacial polymerization (IP) using three different kinds of biomonomers with trimesoyl chloride (TMC) on a polysulfone (PSf) substrate. Biomonomers such as dopamine hydrochloride (PDA), norepinephrine (PNE), and tannic acid (TA) are highly hydrophilic and environmentally friendly. Moreover, these materials can not only strongly adhere to substrates but can also form chemically stable cross-linked networks. The influence of these monomers on the formation of the selective layer was systematically investigated. Furthermore, a series of characterization techniques, including attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential measurement, molecular weight cutoff (MWCO), X-ray photoelectron spectroscopy (XPS) and separation performance experiments, were used to study the properties of the TFC NF membranes. Biomonomer-based TFC NF membrane exhibited a higher water permeability of 8.14 L/m2 h bar with a high rejection for divalent ions (Na 2 SO 4) of 93% compared to TFC NF membranes. [Display omitted] • A nanofiltration membrane was developed using three biomonomers as aqueous phase with trimesoyl chloride (TMC). • High performance TFC NF membrane with relatively higher flux with fixed rejection rate (Na 2 SO 4 ~93%) than other membranes. • The reaction chemistries to form the TFC PA layers between three types of biomonomers and TMC were thoroughly investigated. [ABSTRACT FROM AUTHOR]

In molecular separation using membranes, enhanced parameters, such as an increased flux and selectivity, are required for efficiency. Additionally, in molecular separation using solvents, solvent resistance is critical in preventing solvent-induced damage. However, most membranes lack resistances to specific harsh solvents, and simultaneously enhancing solvent flux and selectivity performance, which exhibit a trade-off relationship, is challenging. In this study, a high-performance solvent-resistant polybenzimidazole (PBI) membrane is fabricated via chemical crosslinking with divinyl sulfone (DVS). The membrane consists of porous finger-like support and dense skin layers, and the uniform DVS crosslinking of the PBI membrane is confirmed via chemical analysis. The DVS-crosslinked PBI membrane exhibits a superior solvent stability and separation performance, with an ethanol permeance and molecular weight cut-off of 5.88 L m−2 h−1 bar−1 and 483 g mol−1, respectively. These values represent an enhanced permeance and rejection performance compared to those of the pristine membrane. The DVS-crosslinked PBI membrane also displays a long-term stability in mepenzolate bromide separation over 72 h. [Display omitted] • Solvent-resistant and high-performance PBI membranes for enhanced molecular separation are fabricated by DVS crosslinking. • Owing to the well-organized structure and uniform DVS crosslinking, the membrane exhibits improved rejection and stability. • The enhanced performance is investigated based on the surface energy of each solvent and membrane. [ABSTRACT FROM AUTHOR]