Building up a Smart Surface with Converse Temperature Dependent Wettability Base on Poly(acrylamide-co-acrylonitrile)

A smart surface with converse temperature dependent (CTD) wettability was fabricated by upper critical solution temperature-type (UCST-type) poly(acrylamide-co-acrylonitrile) (P(AAm-co-AN)) copolymer. The obtained surface exhibits remarkable and reversible hydrophobic-hydrophilic transition depending on temperature with high response rate. The static water contact angle of the surface decreases from 100° ± 2° to 65° ± 1° when the temperature increases from 40 °C to 60 °C. Further, the wettability of the UCST-type surface shows positive linear relationship of wettability with temperature. This study for the first time provides an UCST-type smart surface with wettability decreasing over 35° when temperature increases only 20 °C.