Reversibly Superwettable Polyester Fabric Based on pH-Responsive Branched Polymer Nanoparticles

A responsive function is significant to surfaces with special wettability, especially for breaking through their limitations in practical applications. We report a novel strategy, which is effective, scalable, versatile, and low-cost, to produce the pH-responsive superwettable surface by combining the pH-responsive branched polymer nanoparticles (PRBNs) and conventional textile materials. The PRBN exhibiting a spherical shape with strawberry-like rough surface is able to swell (diameter of 71 nm) in an acidic aqueous solution and shrink to its original size (diameter of 42 nm) in a neutral or basic aqueous solution; moreover, the swelling-shrinking transition is reversible. The deposition of PRBNs on polyester fabric provides the surface pH-responsive wettability that is superhydrophobic to a neutral or basic aqueous solution (pH >= 7) with a contact angle above 150 degrees and superhydrophilic to an acidic aqueous solution (pH 1) with a contact angle of 0 degrees. Similar to the pH-responsive behavior of nanoparticles, this superhydrophobic-supehydrophilic transition of fabric is also reversible. By adjusting the hydrophobic substituents of PRBN, the wettability of fabric has remarkable changes. The adhesion of PRBNs onto polyester fabric can be obviously enhanced by the heating-press procedure so that its washability improves. These results may provide a new horizon to design new-generation smart textiles via utilizing controllable wettability.