Facile fabrication of PTFE/PET composite membrane with reinforced hydrophilic and antifouling properties for sustainable decentralized water system purification

Decentralized water supply in rural regions remains a substantial challenge due to complex natural, technical, and economic constraints. Gravity-driven membrane (GDM) systems represent a promising approach for achieving sustainable water purification in such decentralized supply scenarios. This study developed a facile fabrication strategy for crosslinking PTFE/PET composite membranes (c-PTFE/PET) with reinforced hydrophilicity to improve the water permeance and antifouling performance. After acetalization between polyvinyl alcohol (PVA) and glutaraldehyde (GA), the c-PTFE/PET membrane exhibited superhydrophilicity, likely driven by abundant hydroxyl groups and increased surface roughness. Density functional theory calculations revealed that strong interactions between the PVA-GA complex layer and H 2 O molecules promoted the formation of a dense hydration layer. Compared with conventional PTFE/PET composite membrane, the enhanced properties rendered c-PTFE/PET membrane proficient not only in water permeance (3.17 times), but also outstanding antifouling performance against humic acid and bovine serum albumin solution. Moreover, field application of the resulting GDM system equipped with c-PTFE/PET membrane, with a treatment capacity of 10 m 3 day −1 , demonstrated improved effluent quality, reduced microbial community diversity, and elevated economic efficiency. The c-PTFE/PET membrane also maintained its hydrophilicity after prolonged exposure to chemical environments. This work presents a cost-effective, easily implementable, and highly efficient approach for household water purification in underdeveloped regions.