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The development of smart materials capable of underwater self‐healing, mechanical robustness and damage‐healing sensing attributes holds great promise for applications in marine energy exploitation. However, achieving excellent humidity self‐healing, superior adhesion, and effective damage sensing and monitoring properties simultaneously is challenging because the disturbance of water molecules to dynamic‐interaction reconstruction. Herein, inspired by gecko's toes, an ultra‐robust environmental adaptative self‐healing supramolecular elastomer is designed by molecular engineering of water‐insensitive dynamic network, which possesses efficient self‐healing and visual damage sensing capabilities. Through coupling design of hierarchical hydrogen bonds, humidity‐tolerant catechol coordination and photothermal sensitivity moiety, the elastomer achieves high Young's modulus (157.72 MPa) and superior self‐healing efficiency (84.68%). Moreover, the autonomous association between catechol groups and steel surface endows the resultant elastomer with outstanding adhesion force (12.82 MPa) in humid conditions. Furthermore, this elastomer can be fabricated as a patch covered on steel substrates. The damage‐healing dynamics and interfacial failure characteristics are visually demonstrated by the reversible fracture and reconstruction of iron‐catechol coordination bonds, realizing real‐time damage sensing and monitoring. This study provides a novel strategy for the design of next‐generation smart protective materials in harsh marine environment, and expected for ensuring the stable operation of marine energy mining equipment. Inspired by the gecko's toes, a novel supramolecular elastomer featuring superior adhesion, efficient humidity self‐healing and damage sensing is constructed. The elastomer can be fabricated as a smart patch covered on the damage area of in‐service coatings or equipment surface, achieving damage sensing, visual monitoring, and semi‐quantitative assessment of the structural failure dynamics under marine conditions.

Hydrogels that have both permanent chemical crosslinks and transient physical crosslinks are good model systems to represent tough gels. Such “dual-crosslink” hydrogels can be prepared either by simultaneous polymerization and dual crosslinking (one-pot synthesis) or by diffusion/complexation of the physical crosslinks to the chemical network (diffusion method). To study the effects of the preparation methods and of the crosslinking ratio on the mechanical properties, the equilibrium swelling of the dual-crosslink gels need to be examined. Since most of these gels are polyelectrolytes, their swelling properties are complex, so no systematic study has been reported. In this work, we synthesized model dual-crosslink gels with metal–ligand coordination bonds as physical crosslinks by both methods, and we proposed a simple way of adding salt to control the swelling ratio prepared by ion diffusion. Tensile and linear rheological tests of the gels at the same swelling ratio showed that during the one-pot synthesis, free radical polymerization was affected by the transition metal ions used as physical crosslinkers, while the presence of electrostatic interactions did not affect the role of the metal complexes on the mechanical properties.

This review is devoted to the description of methods for the self-healing of polymers, polymer composites, and coatings. The self-healing of damages that occur during the operation of the corresponding structures makes it possible to extend the service life of the latter, and in this case, the problem of saving non-renewable resources is simultaneously solved. Two strategies are considered: (a) creating reversible crosslinks in the thermoplastic and (b) introducing a healing agent into cracks. Bond exchange reactions in network polymers (a) proceed as a dissociative process, in which crosslinks are split into their constituent reactive fragments with subsequent regeneration, or as an associative process, the limiting stage of which is the interaction of the reactive end group and the crosslink. The latter process is implemented in vitrimers. Strategy (b) is associated with the use of containers (hollow glass fibers, capsules, microvessels) that burst under the action of a crack. Particular attention is paid to self-healing processes in metallopolymer systems.

Recent research has built a consensus that the binder plays a key role in the performance of high‐capacity silicon anodes in lithium‐ion batteries. These anodes necessitate the use of a binder to maintain the electrode integrity during the immense volume change of silicon during cycling. Here, Zn2+–imidazole coordination crosslinks that are formed to carboxymethyl cellulose backbones in situ during electrode fabrication are reported. The recoverable nature of Zn2+–imidazole coordination bonds and the flexibility of the poly(ethylene glycol) chains are jointly responsible for the high elasticity of the binder network. The high elasticity tightens interparticle contacts and sustains the electrode integrity, both of which are beneficial for long‐term cyclability. These electrodes, with their commercial levels of areal capacities, exhibit superior cycle life in full‐cells paired with LiNi0.8Co0.15Al0.05O2 cathodes. The present study underlines the importance of highly reversible metal ion‐ligand coordination chemistries for binders intended for high capacity alloying‐based electrodes. Zn2+–imidazole coordination bonds, crosslinked with carboxymethyl cellulose in situ during electrode fabrication, are introduced as a polymeric binder for high‐capacity silicon anodes. The reversible metal–ligand bonds impart high elasticity to the binder network for keeping the electrode's integrity. The robust cycling performance under commercial levels of areal capacity highlights the usefulness of high elasticity involving metal–ligand bonds.

Bioadhesive gels with robust adhesion on wet and irregular tissue surfaces are desirable for clinical applications. Assembly of bioadhesive powders is an effective strategy for obtaining gels that adhere to wet and irregular tissue surfaces by absorbing interfacial water. However, current bioadhesive powders lack positive biological functions and are prone to postoperative adhesion. Here, we present a powder strategy based on metal-ligand coordination to create a series of bioadhesive polyacrylic acid (PAA) gels. In the gel network, metal ions (M n + ) are used to coordinate with the carboxy ligands of PAA to form dynamic noncovalent crosslinks. The powders can absorb interfacial water and assemble into gels on wet and irregular tissue surfaces within a few seconds, forming an initial adhesion layer by electrostatic interactions. Furthermore, the polymers can diffuse into the tissue matrix, and metal-ligand coordination is reconstructed to enhance the adhesion. Moreover, with a cationic shield layer, the bioadhesive powders can effectively avoid postoperative adhesion. Importantly, ions endow the gel with customized biological functions. We demonstrate that the hemostatic, antibacterial, peroxidase-like catalytic, and photodetachment abilities of the gels by incorporating different M n + ions. These advantages make the bioadhesive powder a promising platform for diverse tissue repair applications.

Iron (II) tris(2,2′-bipyridine) complexes, [Fe(bpy)3]2+, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H2O)6]2+ species by hydrogen bonds to the anionic sulfonate moieties grafted to the silica nanopores. In a first step, thiol-based silica films have been electrochemically generated on indium tin oxide (ITO) substrates by co-condensation of 3-mercaptopropyltrimethoxysilane (MPTMS) and tetraethoxysilane (TEOS). Secondly, the thiol function has been modified to sulfonate by chemical oxidation using hydrogen peroxide in acidic medium as an oxidizing agent. The immobilization of [Fe(bpy)3]2+ complexes has been performed in situ in two consecutive steps: (i) impregnation of the sulfonate functionalized silica films in an aqueous solution of iron (II) sulfate heptahydrate; (ii) dipping of the iron-containing mesostructures in a solution of bipyridine ligands in acetonitrile. The in situ formation of the [Fe(bpy)3]2+ complex is evidenced by its characteristic optical absorption spectrum, and elemental composition analysis using X-ray photoelectron spectroscopy. The measured optical and electrochemical properties of immobilized [Fe(bpy)3]2+ complexes are not altered by confinement in the nanostructured silica thin film.

A series of porphyrin triads (1–4), in which each triad is composed of a Sn(IV) porphyrin and two free-base (or Zn(II)) porphyrins, was synthesized and their self-assembled nanostructures were studied. Depending on the substituent on porphyrin moieties, each triad was self-assembled into a different nanostructure. In particular, the cooperative coordination of 3-pyridyl groups in the Sn(IV) porphyrin with the axial Zn(II) porphyrins in triad 4 leads to forming uniform nanofibers with an average width of 10–22 nm. Other triads without the coordinating interaction between the central Sn(IV) porphyrin and the axial porphyrins formed irregularly shaped aggregates in contrast. The morphologies of nanofiber changed drastically upon the addition of pyrrolidine, in which pyrrolidine molecules break down the self-assembly process by coordinating with the axial Zn(II) porphyrins. All porphyrin aggregates exhibited efficient photocatalytic performances on the degradation of methylene blue dye under visible light irradiation. The degradation efficiencies after 2 h were observed to be between 70% and 95% for the aggregates derived from the four triads.

At this time, the development of advanced elastic dielectric materials for use in organic devices, particularly in organic field-effect transistors, is of considerable interest to the scientific community. In the present work, flexible poly(dimethylsiloxane) (PDMS) specimens cross-linked by means of ZnCl2-bipyridine coordination with an addition of 0.001 wt. %, 0.0025 wt. %, 0.005 wt. %, 0.04 wt. %, 0.2 wt. %, and 0.4 wt. % of gold nanoparticles (AuNPs) were prepared in order to understand the effect of AuNPs on the electrical properties of the composite materials formed. The broadband dielectric spectroscopy measurements revealed one order of magnitude decrease in loss tangent, compared to the coordinated system, upon an introduction of 0.001 wt. % of AuNPs into the polymeric matrix. An introduction of AuNPs causes damping of conductivity within the low-temperature range investigated. These effects can be explained as a result of trapping the Cl− counter ions by the nanoparticles. The study has shown that even a very low concentration of AuNPs (0.001 wt. %) still brings about effective trapping of Cl− counter anions, therefore improving the dielectric properties of the investigated systems. The modification proposed reveals new perspectives for using AuNPs in polymers cross-linked by metal-ligand coordination systems.

Metallogels, three-dimensional supramolecular networks formed through metal–ligand coordination, have emerged as a new generation of adaptive soft materials with promising biomedical potential. By integrating the structural stability and tuneable functionality of metal centres with the dynamic self-assembly of organic gelators, these systems exhibit exceptional mechanical strength, responsiveness, and multifunctionality. Recent studies demonstrate their diverse applications in drug delivery, anticancer therapy, antimicrobial and wound healing treatments, biosensing, bioimaging, and tissue engineering. Interestingly, the coordination of metal ions such as Ru(II), Zn(II), Fe(III), and lanthanides enables the creation of self-healing, thixotropic, and stimuli-responsive gels capable of controlled release and therapeutic action. Moreover, the incorporation of luminescent or redox-active metals adds optical and electronic properties suitable for diagnostic and monitoring purposes. This collection summarizes the most recent advances in the field, highlighting how rational molecular design and coordination chemistry contribute to the development of multifunctional, biocompatible, and responsive metallogels that bridge the gap between materials science and medicine.

Double-shelled hollow (DSH) structures with varied inorganic compositions are confirmed to have improved performances in diverse applications, especially in lithium ion battery. However, it is still of great challenge to obtain these complex nanostructures with traditional hard templates and solution-based route. Here we report an innovative pathway for the preparation of the DSH nanospheres based on block copolymer self-assembly, metal–ligand coordination and atomic layer deposition. Polymeric composite micelles derived from amphiphilic block copolymers and ferric ions were prepared with heating-enabled micellization and metal–ligand coordination. The DSH nanospheres with Fe2O3 stands inner and TiO2 outer the structures can be obtained with atomic layer deposition of a thin layer of TiO2 followed with calcination in air. The coordination was carried out at room temperature and the deposition was performed at the low temperature of 80 °C, thus providing a feasible fabrication strategy for DSH structures without destruction of the templates. The cavity and the outer layer of the structures can also be simply tuned with the utilized block copolymers and the deposition cycles. These DSH inorganic nanospheres are expected to find vital applications in battery, catalysis, sensing and drug delivery, etc.