Facile Strategy to Construct High-Performance Nanofiltration Membranes by Synergy of Graphene Oxide and Polyvinyl Alcohol

Abstract

Graphene oxide (GO), as an emerging nanofiller, is commonly incorporated into the polypiperazine amide (PPA) selective layer to enhance nanofiltration (NF) performance. However, GO’s dispersibility and compatibility present outstanding challenges for fabricating high-performance GO-incorporated NF membranes. In this study, polyvinyl alcohol (PVA) and GO were introduced into the aqueous solution at the same time to enhance the membrane performance by taking advantage of the synergetic effects of GO and PVA. GO’s dispersibility in aqueous solution and its compatibility within the PPA matrix were significantly improved because of the introduction of PVA. Furthermore, both PVA and GO contributed to the diffusion behavior of aqueous monomers for constructing defect-free, rougher, thinner, and more hydrophilic NF membranes. With the introduction of 100 ppm GO and 0.05 wt % PVA into the aqueous solution during the interfacial polymerization process, the optimal thin-film nanocomposite NF membrane exhibited a water flux of 84.2 LMH without reducing the salt rejections (97.6% for Na2SO4), which were 69.1 and 36.7% higher than the pristine thin-film composite (TFC)-blank and TFC-PVA membranes, respectively. Meanwhile, an excellent antifouling performance was achieved with a flux recovery rate of 92.1% because of the lower negative charge and excellent hydrophilicity of the membrane surface. This study develops a simple and effective approach to construct high-performance NF membranes.

Nanofiltration Membranes with Octopus Arm-Sucker Surface Morphology: Filtration Performance and Mechanism Investigation

“…(e) Trade-off relationship between water/salt selectivity (A/B) and water permeance (A). (f) Summary of water permeance and Na 2 SO 4 rejection of TFC NF membranes reported in previous literature. ,,,− Error bars indicate the standard deviation ( n = 6).…”

2D nanosheet enabled thin film nanocomposite membranes for freshwater production – a review

“…It is reported that the introduction of polyvinyl alcohol (PVA) in the aqueous phase during IP reaction, enhanced the dispersion and compatibility of GO resulting in fabrication of highly hydrophilic and defect-free membranes with improved antifouling performance and water permeance. 141 Similarly, synergetic impact of other additives along with 2D nanosheets could be explored. It has been observed that GO nanosheets have a greater impact on antibacterial properties than transport properties, while MoS 2 nanosheets provide enhanced permeation and salt rejection.…”

Poly(vinyl alcohol)‐based membranes for fuel cell and water treatment applications: A review on recent advancements

“…In PVA‐based TFC membrane PVA‐coating can be as a sole selective layer, as intermediate layer or both. Comprehensive studies on the modification of PIPA‐based NF membranes, using PVA, usually includes three strategies: inclusion of PVA into PIPA through IP route for formation of PIPA‐PVA layer, 133,134 formation of PVA‐based polymer layer as an intermediate layer (between the substrate and the top PIPA layer), 135,136 and coating PVA as a top selective layer 137 . Construction of interlayer is done to improve the IP reaction kinetics during the TFC membrane preparation, as well as to enhance the membrane performance.…”

“…PIPA/PVA/PES NF membrane, having PVA as intermediate layer, promoted the formation of nanoscale turning‐like structure, which improved the membrane permeability. While, use of GO nanomaterials along with PVA in the top layer resulted in a higher water permeation, 137 compared to PIPA‐PVA based composite membranes 133,134 . Wagh et al 138 modified polybenzimidazole (PBI)‐based NF membrane by incorporation of aquaporin into the selective layer.…”