Redox-Mediated, Transient Supramolecular Charge-Transfer Gel and Ink

Abstract

Unprecedented spatiotemporal control exhibited by natural systems has aroused interest in the construction of its synthetic mimics. Cytoskeleton proteins utilize fuel-driven dissipative self-assembly to temporally regulate cell shape and motility. Until now, synthetic efforts have majorly contributed to fundamental strategies; however, temporally programmed functions are rarely explored. Herein, we work toward alleviating this scenario by using a charge-transfer (CT) based supramolecular polymer that undergoes structural changes under the effect of a redox fuel. The structural changes in supramolecular assembly amplify into observable macroscopic and material property changes. As a result, we achieve transient chemochromism, a self-erasing ink and self-regenerating hydrogel, whose temporal profile can be regulated by varying the concentrations of the chemical cues (fuel and enzyme). The redox-mediated transient functions in the CT based supramolecular polymer pave way to create next-generation active, adaptive, and autonomous smart materials.

Time-encoded bio-fluorochromic supramolecular co-assembly for rewritable security printing

“…This spontaneous emission variation of the hydrogel system on a time scale is highly plausible, since 1 /ATP disassembles in the hydrogel along with the enzyme-catalyzed hydrolysis process of ATP. 53 Thus, it is evident that the ALP mediated transient assembly of 1 /ATP can be regarded as an effective strategy for the construction of time-encoded emission systems.…”

Transient dormant monomer states for supramolecular polymers with low dispersity

“…The redox-responsive dormant states of assembled radical anions presented here are indeed out-of-equilibrium transient states and hence are analogous to the metastable dormant states formed under kinetic conditions for various chromophoric systems. Hence this approach suggest the use of transient assemblies 57 – 59 as an alternative way of achieving high-energy dormant states for monomers of highly dynamic supramolecular polymers, where metastable dormant states cannot be achieved under kinetic conditions. Further, this approach can be extended to multicomponent assemblies with predictive sequence using monomers with different redox activities and also to nonequilibrium assemblies by coupling to redox cycles 43 .…”

Stimuli responsive dynamic transformations in supramolecular gels

“…Another variant of the redox-responsive dynamic system is the synthesise of temporally regulated transient hydrogels where the assembled structures display a limited lifetime before it undergoes sol formation. 423,441,442 There has been recent interest in constructing transient hydrogels based on redox reactions. Most of such systems are usually developed either from the intermolecular disulfide exchange reactionbased molecular probes, 86,443,444 or from incorporating redox responsive metal ions onto the organic gelator backbone.…”