Multiple Responsive Photonic Prints Through Localized Interpenetrating Polymer Network

M ultiple responsive photonic prints that can be revealed by a thermal or light stimulus are prepared by locally producing interpenetrating polymer network (IPN) within photonic hydrogels. Thermo-responsive poly-( N -isopropylacrylamide) (PNIPAM) photonic hydrogels with self-assembled monodisperse carbon-encapsulated Fe 3 O 4 nanoparticles (Fe 3 O 4 @C NPs) are first prepared by a photopolymerization process. Then photopolymerization of acrylamide (AM) is carried out within the photonic hydrogel with the help of a mask to generate an IPN structure locally. Because of the regionally different network structure and the resulting varied responsiveness, responsive photonic prints are obtained. Due to the thermo-responsive capability of the PNIPAM and the photothermal conversion capability of the incorporated Fe 3 O 4 @C NPs, the as-prepared photonic prints with a localized IPN structure can shift the structural color in a broad spectrum range under thermal or light stimuli. The current multiple responsive photonic prints with a localized IPN structure can realize full-color pattern display under thermal and light stimulations, providing a new path for anti-counterfeiting, display, and information encoding.