Self-growth of programmable 2D- and 3D-coupling responsive coating for anti-counterfeiting.

Programmable dual-mode (two- or three- dimension, 2D/3D)-coupling responsive coating constitutes one of the most promising strategies to ensure the security of anti-counterfeiting and information encryption, but it is still lack of effective approaches to integrate stimuli-responsive 2D and 3D information. Herein, we develop a self-growing method to achieve this purpose based on photoswitchable fluorescence and supramolecular interaction (dipole-dipole interaction) toward advanced multi-dimensional anti-counterfeiting and encryption. In our method, trifluoromethyl-rich monomers (2,2,2-trifluoroethyl methacrylate (TFEMA) and 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA)), polymerizable green fluorescent dye (2-(6-(dimethylamino)-1,3-dioxo- 1H-benzodeisoquinolin-2(3H)-yl) ethyl acrylate, MNEA) and photochromic diarylethene derivative (4-(acryloyloxy) butyl-4-(2-methyl-3-(2-(2-methylbenzo thiophen-3-yl)-4-oxo-5,6-dihydro-4H-thieno 2,3- thiopyran-3-yl) benzo thiophen-6-yl)-4-oxobutanoate, BTBA) are introduced into specific 3D structure via a self-growing method. The coating is capable of reversible fluorescence switching from green to red through photo-induced fluorescence resonance energy transfer (FRET) process between MNEA and BTBA, and reversible switch of 3D structure based on force- and thermo-induced shape memory caused by dipole-dipole interaction and covalent bond. Interestingly, when the 2D information is stimulated, the 3D information remains unchanged. Several examples demonstrate that the great application potential of the programmable responsive coating in high-security of multilevel anti-counterfeiting and information encryption. We thus envision the great potential of our method in developing advanced anti-counterfeiting, multilevel information encryption and high-density data storage.