A novel glue attachment approach for precise anchoring of hydrophilic EGCG to enhance the separation performance and antifouling properties of PVDF membranes

[Display omitted] •A green EGCG-ESBR layer was designed to improve the antifouling ability of the PVDF membrane.•Ring opening of the active site of SBR enabled precise coating with EGCG by hydrogen bonding.•The protein filtration and oil emulsion separation performances were investigated to evaluate the results.•The modified PVDF showed a durable antifouling ability and separation performance after long-term tests. A novel glue attachment approach was proposed to form a durable hydration layer on a hydrophobic PVDF hollow fiber membrane (PVDF HFM) surface to improve its hydrophilicity and antifouling ability during wastewater filtration. The functional glue was synthesized from reclaimed styrene butadiene rubber (SBR) and a hydroxyl group was created with an epoxidation reaction (ESBR). The hydrophilic epigallocatechin-s-gallate (EGCG) was then precisely anchored via hydrogen bonding with multiple phenolic hydroxyl groups in the ESBR without penetrating into the inner matrix of the PVDF to prevent flux decline. The hydrophilicity of the PVDF membrane increased drastically and the water contact angle decreased from 62.7° to 45.1° with only a 25% decline in the pure water flux. Furthermore, due to precise anchoring of the EGCG, the modified EGCG-ESBR/PVDF membrane showed a higher pure water flux (110.6 L m−2h−1) and much higher BSA and oil (kerosene) rejection rates (approximately 94.5% and 99.5%, respectively) compared to membranes directly coated with EGCG (EGCG-PVDF). Moreover, the modified membrane also showed higher water flux recovery after multiple filtration cycles. This promising and efficient hydrophilic modification suggests great potential for application of the eco-friendly material in wastewater treatment.