Rapid Fabrication of Alcohol Responsive Photonic Prints with Changeable Color Contrasts for Anti‐Counterfeiting Application

Abstract Efficient fabrication of responsive photonic prints (RPPs) with specific functionalities is imminently desired owing to its applications in display, anti‐photobleaching, and anti‐counterfeiting. Here, RPPs with changeable color contrasts are fabricated through the region selective swelling of the swellable photonic crystals paper with 2‐hydroxyethyl methacrylate (HEMA) as ink followed by fixing the structures of the swelled regions by photopolymerization. The fabrication process is considerable simple, fast, and efficient, and multicolor RPPs with any desired patterns can be generated within 6 min. Different from the dual/triple color contrasts of conventional RPPs, the as‐prepared RPPs can instantly and reversibly show five color contrasts [(blue/transparent/green/yellow/red)‐red] in the alcohol solution owing to the asymmetric swelling behavior between the background and pattern. The similar solubility parameter between the photonic paper and HEMA/ethanol is the key for the fast fabrication process and abundant color contrasts of RPPs in solvents. The simple and rapid fabrications as well as the responsive properties will extend the applications of RPPs in color display, information storage, and anti‐counterfeiting.