A Convenient, Environmental-Friendly, Panchromatic Adjustable, Re-Writable Photonic Paper and Its Optical Anti-Counterfeiting Application

Multi-responsive re-writable photonic paper (MRPP) with inverse opal structure was prepared by introducing [poly(hydroxyethyl methacrylate)-poly(dimethylamino ethyl methacrylate)-poly(N-isopropyl acrylamide)] (PHEMA-PDMAEMA-PNIPAM) multi-responsive gel (MRH) into silica (SiO2) photonic crystal (PC) template. First, monomers such as HEMA, DMAEMA, and NIPAM were filled into the SiO2 PC template. Then, MRPP with dynamic responsive color change capability was prepared by ultraviolet (UV) curing and hydrofluoric (HF) etching. MRPP has temperature, pH, ionic strength, and ethanol concertration responsiveness, fast wetting capability (-1.4 s), strong re-writability (-600 cycles), and the ability to use inorganic salt solution as an environmental-friendly ink to achieve panchromatic adjustment. Based on the multiple responsiveness of MRPP and its difference in solvent volatility, a time-temperature dependent optical anti-counterfeiting system with higher security level and fast identification of encryption was successfully constructed. The excellent performance of MRPP indicates its great application value in the field of re-writable photonic paper as well as information security.