Ru(II) Catalyst Enables Dynamic Dual‐Cross‐Linked Elastomers with Near‐Infrared Self‐Healing toward Flexible Electronics

Abstract

Perusing elastomers capable of self-healing offers new opportunities to enable next-generation flexible electronics, but remains greatly challenging; because, few of them can simultaneously possess desirable mechanical strength, elasticity, and self-healing efficiency. Herein, a dynamic dual-crosslinked networks strategy is employed to develop the elastomers via synthesis of ionic polymer catalyzed using the Grubbs's third-generation catalyst (G3) and subsequent ureido-pyrimidinone (UPy) grafting. Specifically, UPy exhibits a unique gradient distribution on ionic polymer chains. Large UPy clusters form in the dense UPy region with robust cross-links that can stabilize the system, while UPy dimers in sparse regions with weak ionic interactions can act as sacrificial bonds for energy dissipation. Therefore, the obtained elastomers exhibit superb mechanical properties with high stretchability (1900%), high toughness (33.8 MJ m −3 ), and excellent elasticity (>85%). Importantly, deactivated [Ru] = CHOEt complex (G3 derivative) is proved to have an inherently outstanding photothermal effect under near-infrared (NIR) irradiation. Benefiting from this feature, the elastomers achieve nearly complete self-healing within 4.5 min under NIR. Furthermore, the elastomers are employed as the base materials to construct flexible self-healing conductors with stable conductivity even being stretched to 1200%. This work exercises a profound influence on the rational design of high-performance self-healing elastomers.

Photochemically driven one-step triple dynamic network formation in printable tough hydrogel for self-healing tubular sensors

“…Moreover, increasing the self-healing temperature could accelerate the mobility of UPy residues, PVAA chains, and Ca 2+ ions, leading to an increase in the self-healing efficiency of PSHTHs. 59 The comparison in Fig. 3h shows that the specific efficiency was only 36% when the control sample was healed at room temperature.…”

Dynamic covalent bond and metal coordination bond-cross-linked silicone elastomers with excellent mechanical and aggregation-induced emission properties

“…The prepared elastomers exhibited excellent tensile properties (1900%), high toughness (33.8 MJ m −3 ), and excellent elasticity. 42 On the other hand, the combination of supramolecular self-assembly and covalent chemistry in the biological assembly process can construct artificial structures that are thermodynamically and kinetically stable. 43 In particular, Schiff bases are not only commonly used for dynamic covalent bonding, 44,45 but also have excellent coordination ability due to the presence of a lone pair of electrons on the nitrogen atom; 45–48 thus, different metal complexes were introduced into the polysiloxane network to construct a dual cross-linked network, and thereby elastomers with improved mechanical properties were obtained.…”

Multifunctional Polyurethane Networks Combining Strength, Toughness, and Fast Autonomous Self-Healing via the Synergy of Multiple Dynamic Bonds

“…Self-healing polymers have the capacity to repair themselves after recurrent injury, restoring their physical properties and consequently extending the service lifetime of materials and reducing maintenance costs. Such materials have been developed and used in many applications, including flexible electronics, sensors, − electronic skin, , supercapacitors, , conductive films, rechargeable batteries, healthcare products, and biomedical materials. − However, engineering robust and tough materials with superior self-healing efficiency at room temperature has been a challenge because high mechanical strength comes at the cost of decreased polymer chain mobility required for self-healing. To address this challenge, researchers developed intrinsically healing materials based on noncovalent interactions such as metal–ligand coordination, , π–π stacking, H-bonding, host–guest complexation, ionic interaction, and van der Waals interactions, or dynamic covalent bonds such as disulfide metathesis, boronic esters, boroxines, diselenide metathesis, oxime chemistry, sterically hindered urea, and Diels–Alder chemistry.…”