Out‐of‐equilibrium supramolecular self‐assembling systems driven by chemical fuel

Abstract

A rich variety of smart materials developed via supramolecular assembly strategies have been introduced in the past decades. However, most materials reside in the thermodynamic equilibrium state, opposed to those nonequilibrium structures with sophisticated functions that are observed in living systems. To develop advanced synthetic systems, chemists have begun to focus on how to use strategies similar to those used in biological systems for fabricating artificial out-of-equilibrium systems. Heretofore, a rich variety of artificial out-of-equilibrium systems have been developed. In this review, we have summarized the recent progress of artificial out-of-equilibrium systems and categorized them in terms of the chemical fuel used, including adenosine triphosphate (ATP), acid/base, carbodiimide reagents, and many others. For these self-assembling systems, their design strategies, potential applications, as well as advantageous features have been discussed. At the end of this review, the remaining challenges and an outlook of the chemical-fuel-driven out-of-equilibrium systems were also discussed. It is believed that this review has provided some insights and could be useful for those who are interested in the out-of-equilibrium supramolecular assembling systems and their subsequent constructing strategies for various transient materials.

Bioinspired Self-Resettable Hydrogel Actuators Powered by a Chemical Fuel

“…Thus far, significant efforts have been made to develop nonequilibrium smart hydrogels controlled by synthetic CRNs. − A pioneering example is active hydrogels controlled by the exceptional Belousov–Zhabotinsky reaction, resulting in oscillating actuation of the hydrogels. , Nonetheless, the Belousov–Zhabotinsky reaction often suffers from the problems of poor control and fairly difficult design, stagnating the further advancement of hydrogels. In recent years, scientists have coupled chemical fuel-regulated nonequilibrium CRNs to molecular self-assembly − and dynamic cross-linking of hydrophilic polymers, − giving rise to various active hydrogel materials that show fuel-controlled autonomous hydrogelation behaviors. Very recently, Walther’s and Matsusaki’s groups have further extended this concept to enable transient volume-phase transitions of hydrogels, adding a step to the development of autonomous hydrogel actuators, although these systems suffer from serious deteriorations caused by the accumulation of wastes or slow response speed (days).…”

Using Rheology to Understand Transient and Dynamic Gels

“…However, there is an increasing interest in gels which have controllably changing properties. Transient gels as well as gels that are formed by fueled systems are a growing field, partially driven by a generic interest in systems chemistry as well as by potential analogy with biological systems [ 1 , 2 , 3 , 4 , 5 ].…”

Harnessing solution and solid-state emissive materials from aliphatic biogenic amine-induced transient assembly and spontaneous disassembly

“…It must be noted that the transient assembly occurring here is not exactly an ideal out-of-equilibrium system that needs a constant influx of fuel to control the transient assembled state. 51,52 Here, aliphatic biogenic diamines act as activators of pyrene dianhydride (Py-DA) precursors for the self-assembly and disassembly process. Biogenic diamines are recognized as low molecular weight organic bases, widely found in plants, microbes, animal cells, fish, meat, and dairy products.…”

“…It must be noted that the transient assembly occurring here is not exactly an ideal out-of-equilibrium system that needs a constant influx of fuel to control the transient assembled state. 51,52…”