A Functioning Macroscopic “Rubik's Cube” Assembled via Controllable Dynamic Covalent Interactions

Abstract

The dynamic behavior of a macroscopic adhered hydrogel stabilized through controllable dynamic covalent interactions is reported. These interactions, involving the cross‐linked formation of a hydrogel through reaction of a diacylhydrazine precursor with a tetraformyl partner, increase as a function of time. By using a contact time of 24 h and different compounds with recognized aggregation‐induced emission features (AIEgens), it proves possible to create six laminated acylhydrazone hydrogels displaying different fluorescent colors. Blocks of these hydrogels are then adhered into a structure resembling a Rubik's Cube, a trademark of Rubik's Brand Limited, (RC) and allowed to anneal for 1 h. This produces a 3 × 3 × 3 block (RC) wherein the individual fluorescent gel blocks are loosely adhered to one another. As a consequence, the 1 × 3 × 3 layers making up the RC can be rotated either horizontally or vertically to produce new patterns. Ex situ modification of the RC or application of a chemical stimulus can be used to produce new color arrangements. The present RC structure highlights how the temporal features, strong versus weak adhesion, may be exploited to create smart macroscopic structures.

Aggregate Science: From Structures to Properties

“…Such materials would have great potential for application in signal detection, information storage, etc. [255][256][257][258][259]…”

Polymorph selectivity of an AIE luminogen under nano-confinement to visualize polymer microstructures

“…AIE describes a general phenomenon in which molecules are nonluminescent in solution but give intense emission when aggregated. [22][23][24] The restriction of intramolecular motion (RIM) has been recognized as the mechanism of the AIE phenomenon, which prevents the dissipation of excited-state energy through nonradiative decay channels. [25][26][27] According to the RIM mechanism, the AIE systems have been successfully exploited to examine local microenvironments.…”

Precise Macroscopic Supramolecular Assemblies: Strategies and Applications

“…For example, Harada et al demonstratedt hat the host/guest molecularr ecognition between hydrogels modified with a-cyclodextrin and those with azobenzene couldb er egulated through irradiation with visible light and UV light to realizea ssembly and disassembly, correspondingly,w hich is caused by the different binding constant between a-cyclodextrin and trans-azobenzene/cis-azobenzene. [26] Furthermore,n ew functional supramolecular systemsh ave been explored for applications such as tissue scaffolds, [21,48,49] soft actuators, [32,34,50] coding/encoding, [29,51] "Rubik's Cube", [52] supramolecular glue, [38,43,50,53,54] LED devices, [30] etc.…”