The fabrication of pH-responsive polymeric layer with switchable surface wettability on cotton fabric for oil/water separation

Cotton textile with special surface wettability has a promising future for oil/water separation due to its high adsorption capacity and low cost. A facile method was employed to prepare a durable polymeric layer with pH-triggered switchable surface wettability on cotton fabric. An amino-containing dye intermediate (2-Chloro-4,6-diamino-1,3,5-triazine, CDATA) was used to produce more reactive grafting sites for surface initiated atom transfer radical polymerization (SI-ATRP) of poly(methacrylic acid) (PMAA). The obtained cotton-PMAA fabric showed high pH-responsibility, which was indicated by the shift of O–C=O peaks in Infrared (IR) spectrum and the transition of water/oil contact angle (WCA/OCA). Moreover, with the rising pH, the surface transited from superhydrophobic to superhydrophilic and underwater superoleophobic, leading to efficient oil/water separation. This study provides an innovative way to fabricate smart cotton fabric with high efficiency and high selectivity for oil/water separation.