Thermally driven interfacial switch between adhesion and antiadhesion on gas bubbles in aqueous media

It is greatly important to understand the gas bubble behaviors and realize their reliable manipulation. There still remain many challenges in the capture, transport, and release of gas bubbles at a preferred location intelligently. Herein, we provide a simple approach to manufacture a composite film with poly(N-isopropylacrylamide) (PNIPAAM) and polypropylene that exhibits smart, reversible, and reliable regulation of gas bubble adhesive behaviors (high and low adhesion) by controlling the temperature (above or below the lower critical solution temperature). By adjusting the composite surface temperature, thermally driven interface switching between intermolecular and intramolecular hydrogen bonding of the PNIPAAM chains resulted in low and high adhesion of air bubbles in an aqueous medium. Gas bubbles could be precisely captured, directionally transported, and precisely released at any preferred location.