Stable pH-responsive superhydrophobic fabric based on AgNPs/copolymer composites for controllable oil-water separation

Abstract

In recent years, intelligent response membrane materials have aroused considerable interest in controllable oil-water separation. However, challenges such as unstable response repeatability and easy bacterial contamination continue to hinder their effective use. Herein, a superhydrophobic fabric with pH responsiveness and antibacterial property were synthesized by combing (3-mercaptopropyl)trimethoxysilane (MPTMS) with AgNPs and pH-responsive polymer (DVM) on a fabric substrate. The fabric persisted superhydrophobicity with a WCA of 156o under natural conditions, while underwent a controlled transition of surface wettability in acidic environments. Heavy oil-water mixtures and light oil-water mixtures achieved controllable separation both before and after pH response. The fabric exhibited outstanding oil-water separation capability, achieving a separation efficiency of 98.0% and a separation flux of up to 11025.0 L·m-2·h-1. The pH response and oil-water separation demonstrated excellent repeatability. Specially, the pH responsiveness was maintained for up to 10 cycles, and the oil-water separation remained repeatable for up to 15 cycles. Even when tested under various environmental conditions, the superhydrophobicity was retained. Additionally, the fabric possessed remarkable antibacterial property with an efficiency reaching 90.4%. The preparation of the superhydrophobic fabric serves as a valuable reference for developing multifunctional and stable intelligent materials for oil-water separation.