Molecular-Nano Integrated Design of Hydrogel Hybrid Membranes for Oily Organic Wastewater Treatment

Global industrialization has intensified the discharge of organic pollutants into aquatic ecosystems, with highly toxic and recalcitrant industrial wastewater emerging as a critical constraint on sustainable ecological development. Herein, a hydrogel coating fabrication strategy combining solvent-induced phase separation and nanoparticle hybridization was developed to generate hydrogel coatings with high surface roughness and uniform porous structure, addressing the trade-off between separation flux and separation efficiency that constrains conventional hydrogel oil-water separation membranes. The spatial confinement effect of these nanoparticles was leveraged in conjunction with solvent-induced phase separation to enable one-step, controllable construction of a hierarchical porous structure. This approach integrates three functions-initiation, pore formation, and functionalization-within a single nanocomponent. Based on this approach, we fabricated a zwitterionic gel membrane featuring systematic molecular- and nano-level design and assembly. TiO₂ nanoparticles are used to replace conventional photo initiators, thereby initiating the photopolymerization of sulfobetaine methacrylate (SBMA). The resulting hydrogel hybrid membrane exhibits superhydrophilicity, underwater superoleophobicity, and robust antifouling properties. It achieves > 99.5% separation efficiency for oil-in-water emulsions while enabling pollutant degradation and membrane self-cleaning through photocatalytic activity. This design strategy offers a novel paradigm for the green fabrication of advanced separation membranes and enables scalable preparation of high-performance water treatment membranes.