Conductive superhydrophobic fabric with dual-induced pH-response for controllable oil-water separation

pH-Responsive superwetting materials have found increasingly extensive applications in oil-water separation. To broaden the response range of such materials, researchers have proposed dual pH-responsive materials for this application. While these materials exhibit wettability transitions under both acidic and alkaline conditions, they are still limited by poor recovery of superhydrophobicity. To address this limitation, a conductive superhydrophobic fabric with alkaline-responsive properties was fabricated by introducing silver nanowires onto the textile substrate followed by grafting hydrophobic and pH-responsive functional chemicals. The CG/Ag-S fabric exhibited excellent superhydrophobicity (water contact angle at 153.7°), and presented dual-induced pH response to both alkaline conditions and electric field. Notably, the fabric maintained its superhydrophobicity and stable responsiveness after 13 response cycles, with alkaline droplets (pH at 13) fully permeating through it within 30 s. Additionally, electrolysis-induced surface alkalization enabled water to wet and permeate through the fabric within 60 s for effective light oil-water separation. In oil-water separation tests, the CG/Ag-S fabric achieved a separation efficiency of 95.4 % for heavy oil-water mixtures with a flux of 1.68 × 10 4 L·m −2 ·h −1 before pH response, and a separation efficiency of 97.8 % for light oil-water mixtures with a flux of 1.72 × 10 4 L·m −2 ·h −1 after pH response. The design of dual-induced pH-mono-responsiveness solves the superwettability recovery challenge of pH-dual-responsiveness materials, and the dual-induced response capability also broadens the response range of pH-responsive materials.