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 (SiO 2 ) photonic crystal (PC) template. First, monomers such as HEMA, DMAEMA, and NIPAM were filled into the SiO 2 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.