Stepwise Stimuli‐Responsive, Multicolor‐Chromic Perylene Bisimide/Polyvinyl Alcohol Co‐assembly System for Information Encryption

Abstract

The issue of information security has become a concern in all aspects of daily life, prompting the development of encryption technologies. Therein, optical encryption using color/graphical patterns holds great potential. However, current approaches generally rely on monochromic change upon one or more stimuli, limiting their further application in advanced confidential encryption. Herein, we propose a delicate strategy based on a co-assembly system of perylene bisimides (PBI)/polyvinyl alcohol (PVA) that demonstrates stepwise stimuli response and multicolor changes. The color of the supramolecular system changes from red to purple under the stimulus of UV light, and to orange when exposed to water. The multidimensional chromic response is achieved by an evolution process including the generation, packing rearrangement and quenching of PBI radical anions/dianions. With the virtues of photo-and hydrochromism, this novel coassembly system was successfully employed for advanced anticounterfeiting and versatile information encryption applications.

Non-monotonic Information and Shape Evolution of Polymers Enabled by Spatially Programmed Crystallization and Melting

“…Specifically, the initial and final states can be defined as equilibrium state 1 (ES1) and equilibrium state 2 (ES2), respectively; while the state in between is referred to as the intermediate state (IS). Achieving this transition between multiple states often requires the introduction of several different stimuli, − which may be challenging in some special environments such as in the human body or outer space. Therefore, it is significant to achieve non-monotonic evolution under constant external stimulus.…”

Tuning conductivity while maintaining mechanical properties in perylene bisimide hydrogels at physiological pH

“…Perylene bisimides (PBIs) are very interesting small molecules due to their gelation, conductivity, and thermal and optical properties. 17,18 They have been used to form gels useful for applications such as sensors, 19 H 2 evolution 20 and chromic materials 21 to name a few. They provide an interesting example of an active gel network that provides mechanical and electronic properties without the need for another material present.…”