In\nSitu Growth of Multiresponsive Structural Color\nPatterns within Hydrogels for Multiple Information Encryption

Mimicking\nnatural organisms to directly fabricate multiresponsive\nstructural color patterns from small molecules is of great significance\nfor information encryption but remains challenging. Herein, we present\na bionic entanglement-interlocking microphase separation strategy\nfor in situ growth of multiresponsive structural color patterns within\nhydrogel matrixes. The precursor solutions of common polymerization-induced\nphase-separated materials are used as small-molecule nutrients. The\nnewly generated polymer networks can thus spontaneously collapse into\nphase-separated microspheres within hydrogels during polymerization.\nIn particular, the dense internetwork entanglements form between the\nmicrospheres and hydrogel networks during phase separation, anchoring\nthe microspheres firmly onto hydrogel networks to hinder their gathering.\nConsequently, these newly grown microspheres can be maintained at\nthe desired nanoscale for yielding the structural blue color by light\nscattering. Multiresponsive schemochrome patterns can be readily created\nby growing different microspheres within hydrogel matrixes for multiple\ninformation encryptions. We demonstrate that this facile self-growth\nstrategy is applicable to different polymerization-induced phase-separated\nmaterials and hydrogel matrixes, regardless of cross-linking modes\nand geometries.