Bioadhesion-inspired surface engineering constructing robust, hydrophilic membranes for highly-efficient wastewater remediation

The membrane separation technique can strongly advance the energy-efficient water remediation due to its low cost and small footprint. However, the inherent hydrophobicity of most polymeric membrane materials limits the water-treatment efficiency, which urgently requires to develop surface hydrophilization engineering on hydrophobic polymeric membranes. Inspired by the structure/function characteristics of robust mussel/tunicate adhesive proteins, a one-step, eco-friendly, and cost-effective biomimetic coating system was designed and utilized to realize membrane surface hydrophilization via the intermolecular “amino/mercapto-pyrogallol bridges”. The as-coated poly(vinylidene fluoride) micro-/ultra-filtration (MF/UF) membranes exhibited greatly enhanced wettability , good harsh condition tolerance, high filtration efficiency, and excellent fouling resistance. Both of emulsified oily and simulated protein wastewater were remediated accordingly. The optimal MF membrane demonstrated a pure water flux as high as ca. 7900 L m −2  h −1 (47 times higher regarding the pristine membrane), and oil rejection efficiency beyond ca. 99.5% during the cycling emulsion filtration tests. The coated UF membrane possessed a benign protein interception efficiency (BSA rejection of ca. 95.4% with water flux of ca. 400.7 L m −2  h −1 ) and greatly enhanced fouling resistance (78.0% increment). The new biomimetic synergistic coating strategy can promote the rapid development of advanced membranes via elegant surface manipulation towards water-energy nexus.