Supramolecular Metallogel That Imparts Self-Healing Properties to Other Gel Networks

Abstract

A unique proton conductive and moldable supramolecular metallogel (CuA-Ox gel) made upon mixing at room temperature well-defined stock solutions of Cu­(OAc)2·H2O and oxalic acid dihydrate was found to have self-healing properties. Remarkably, the system also displayed an unprecedented ability to impart self-healing properties to other gel networks lacking this capacity. A self-healed CuA-Ox metallogel was found to have essentially the same nanofibrillar morphology, thermal stability, rheological properties, and conductivity as the freshly prepared sample. The discovery also allowed the fabrication of self-healing conductive composites containing conductive carbonaceous materials. Overall, this work serves as a proof of concept for the transfer of self-healing properties between completely different gel networks.

Stimuli‐Responsive Metallogels for Synthesizing Ag Nanoparticles and Sensing Hazardous Gases

“…In metallogel, metal-ligandc oordination alongw ith other noncovalent interactions facilitates the formationo fS AFiN. Metallogelation is reportedt ob eexerted by randomc oordination polymers, [44,45] hyper-branched coordination polymers, [46] coordinationc omplexes [47][48][49] etc. Designing gelators is ac hallenging task because exact details of molecular level gelation mechanism are stillu nclear.N evertheless, there have been efforts by various groupst od esign metallogelators.…”

Rheoreversible Metallogels Derived from Coordination Polymers

“…Such gels that contain metal ions as an integral part are called “metallogels” . Various gelating agents have been reported to effect metallogel formation, including discrete metal‐coordination complexes, well‐defined coordination polymers, and cross‐linked coordination polymers . In each case, highly directional metal−ligand bonds govern the self‐assembly process to generate a fibrous network of metallogels.…”

“…Indeed, materials with rheoreversible properties have numerous potential applications, such as subcutaneous and topical applications and tissue engineering . In general, various supramolecular interactions, such as hydrogen‐bonding, π⋅⋅⋅π interactions, and hydrophobic interactions, play an important role in generating rheoreversible properties in metallogels . We aimed to develop rheoreversible metallogels that were derived from pyridyl ligands by using a crystal‐engineering approach.…”

“…[13][14][15][16] Such gels that contain metal ions as an integral part are called "metallogels". [17][18][19][20] Various gelating agents have been reported to effect metallogel formation,i ncluding discrete metal-coordination complexes, [21] well-defined coordination polymers, [22][23][24] and cross-linked coordination poly-mers. [25] In each case, highly directional metalÀligand bonds govern the self-assembly process to generate af ibrous network of metallogels.I nr ecent years, metallogels have flourished as ap romisingf ield of research, owing to their applications in sensors, [26] proton conduction, [27,28] magnetic materials, [29] catalysis, [30] and nanoparticle templating.…”

“…[40] In general,v arious supramolecular interactions, such as hydrogen-bonding, p···p interactions, andh ydrophobic interactions, play an important role in generating rheoreversiblep roperties in metallogels. [41,24] We aimed to develop rheoreversible metallogels that were derived from pyridyl ligandsb yu sing ac rystal-engineering approach.…”