LAUSR

Poly(N-[4-[(4-Nitrophenyl)azo]phenyl]acrylamide [poly(NPAPAA)] brushes were obtained via interface-mediated reversible addition–fragmentation chain transfer polymerization to design new photoresponsive surface on the graphene oxide coated silicon substrate. Switchable surface wettability was controlled successfully by these densely packed polymer brushes using light as the exterior stimulation. The relatively nonpolar trans azobenzene polymer brushes were converted to a polar cis form (with a larger dipole moment) utilizing light of the suitable wavelength. This conversion is reversible and can be switched back by employing visible light. Cis–trans photo-induced isomerization provided a reversible contact angle change (~ 9o) with UV and visible light for the poly(NPAPAA) brushes under successive irradiation cycles. This study may be promised to control cell culture surface without leaving any residual in terms of alternative medicine.