A stimuli-responsive coaxial nanofilm for burst release

Polymeric nanofilms which change dimensions in response to environmental stimuli, such as temperature, open the possibility for the development of smart surfaces. We demonstrate the synthesis of a coaxial nanofilm with a hydrogel core and a shape memory shell to form temperature activated nanotubes. The nanofilm is fabricated by conformally coating the pores of anodic aluminium oxide membranes with a shape memory polymer shell and a hydrogel core using initiated chemical vapor deposition. The temperature response of the coaxial nanofilm is studied through the time release of a fluorescent dye encapsulated and adsorbed by the hydrogel layer. It is demonstrated that the burst release of the fluorescent dye occurs due to the stress applied by the shape memory outer layer when activated at elevated temperature.