Weizheng Li

Supramolecular adhesives enable on‐demand detachment due to their dynamic nature. However, such behavior usually at the cost of limited adhesive toughness. To promote the intrinsic compromise between adhesive toughness and switchability, we propose a soft‐confinement‐regulated nanorod crystallization strategy to construct a supramolecular elastomer (PTA‐PCL). The amphiphilic and soft poly (thioctic acid) (PTA) matrix forms a dynamically confined interface through hydrogen bonding, directing the oriented self‐assembly of hydrophobic polycaprolactone glycol (PCL‐OH) into nanorod crystals with an aspect ratio of 4.80 and thereby reinforcing the network. Meanwhile, thermally triggered phase transitions drive mesoscale evolution, allowing the adhesion state to be tuned by the dynamic confinement interface. Benefiting from this hierarchical structural design, the PTA‐PCL film exhibited robust adhesion (1609.31 J m ^{− 2} ), switchable debonding (83.7 J m ^{− 2} ; switching ratio = 14.5), and high toughness (3.35 MJ m ^{− 3} ). Molecular dynamics simulations indicated partial compatibility and strong interfacial interactions between PTA and PCL‐OH, while the synergistic coupling between interfacial enrichment and crystallization reinforcement was confirmed by low‐field solid‐state NMR. Overall, this study presents a new strategy for inducing nanorod crystallization within soft networks, and the superior switchable adhesion and interfacial toughness make PTA‐PCL a promising candidate for advanced adhesive materials.

Viscoelastic creep in elastomer originates fundamentally from the molecular‐scale slippage and disentanglement of polymer chains governed by weak intermolecular interactions and imperfect crosslinking. Consequently, residual strain generated by long‐term mechanical loading severely limits the mechanical stability of gel materials. In this study, we proposed a sub‐unit‐cell‐scale defect engineering induced toughening strategy for fabricating creep‐free hyperelastic hydrogels. Within the nanospaces created by linker and cluster defects in metal–organic frameworks (MOFs), strong confined interaction between in situ polymerized polymers and MOF crystals enables rapid self‐reinforcement and remarkable creep resistance. The as‐prepared hydrogels exhibited low hysteresis with full recovery under 99% compressive strain, negligible creep, and outstanding fatigue resistance over 25 000 loading cycles. These features render our hydrogels a promising candidate for drift‐free iontronic sensors, allowing long‐term stable monitoring in air, underwater, and other complex environments.

Viscoelastic creep in elastomer originates fundamentally from the molecular‐scale slippage and disentanglement of polymer chains governed by weak intermolecular interactions and imperfect crosslinking. Consequently, residual strain generated by long‐term mechanical loading severely limits the mechanical stability of gel materials. In this study, we proposed a sub‐unit‐cell‐scale defect engineering induced toughening strategy for fabricating creep‐free hyperelastic hydrogels. Within the nanospaces created by linker and cluster defects in metal–organic frameworks (MOFs), strong confined interaction between in situ polymerized polymers and MOF crystals enables rapid self‐reinforcement and remarkable creep resistance. The as‐prepared hydrogels exhibited low hysteresis with full recovery under 99% compressive strain, negligible creep, and outstanding fatigue resistance over 25 000 loading cycles. These features render our hydrogels a promising candidate for drift‐free iontronic sensors, allowing long‐term stable monitoring in air, underwater, and other complex environments.

The mechanical properties of covalently crosslinked gels or elastomers stem from the crosslinking of the polymer chains and entanglement. Increasing the crosslinking density of covalent networks improves their entropic elasticity but also increases their brittleness. Addressing conflicts between rigidity and toughness, large strains, elasticity, and crack extension presents a challenging task. Here, we present a spatial crosslinking (SC) strategy utilizing a spider‐like crosslinker to materialize creep‐resistant, and low‐hysteresis hydrogels under substantial deformations ( ε = 6000%). The SC approach not only boosts the entropic elasticity of the hydrogels but also disperses stress arising from fractured polymers, leading to notable enhancements in fracture strain, toughness, and crack propagation strain (8200%). Furthermore, the SC hydrogels exhibit the remarkable ability to endure 99% of the ultimate compressive strain at the fully swollen state, along with rapid rebound and creep‐free capabilities, rendering them highly promising candidates for various applications such as drift‐free sensor, artificial blood vessels, and soft robotics.

High‐rate impact loading causes structural failure and insufficient energy dissipation in protective materials. The intrinsic stiffness–damping trade‐off in polymer materials makes it highly challenging to simultaneously achieve strong damping and broad frequency energy dissipation. Here, we developed tough ionogels with enhanced shear‐stiffening and damping capabilities through the synergy of dynamic bonds and steric hindrance of hyperbranched polymeric ionic liquids (HPILs). The synergistic coupling of dynamic‐bond dissociation in the high‐frequency regime and the topological constraint of viscous‐flow HPILs in the low‐frequency regime endows the ionogels with broad‐frequency damping and pronounced shear‐stiffening behavior. The prepared ionogel shows an 842‐fold shear‐stiffening response and high damping (tan δ > 1) across a wide frequency range (10 ^{− 3} –10 ⁵ rad s ^{− 1} ). At a high impact rate of 4000 s ^{− 1} , it also exhibits high impact strength (248.6 MPa) and toughness (86.5 MJ m ^{− 3} ). This strategy provides a reference for the design of next‐generation high‐performance damping ionogels.

Synthesis of ionogels by photoinitiation and thermal initiation suffers from strict conditions and poor biocompatibility. In addition, achieving high mechanical strength and strong adhesive strength simultaneously remains difficult for ionogels. Herein, we report a bio‐ionic liquid‐induced self‐initiated strategy for the rapid and in situ polymerization mediated by liquid metal, which enables the fabrication of tough ionogels with favorable biocompatibility and robust interfacial adhesion. The malic acid/L‐(−)‐carnitine‐based ionic liquid disrupted the surface oxide layer of the liquid metal to accelerate in situ polymerization while simultaneously constructing a dynamic topological network through strong, reversible interactions with the polymer. This endowed the ionogel with high fracture strength (7.2 MPa), toughness (41.7 MJ m ⁻³ ), and strong adhesion (7.6 MPa on glass). Ionogels exhibited photothermal responsiveness, enabling thermally reversible adhesion and real‐time adhesion states monitoring. Owing to good tissue adhesion, ionogels served as bioelectrodes for stable acquisition of physiological signals. This work offers meaningful guidance for the rational design of ionogels for applications in intelligent adhesives and bioelectronics.

The development of flexible fuel cells has been hindered by the rigid components and stringent requirements for pressure encapsulation and fuel sealing. Here we report an adaptive internal pressure encapsulation strategy that leverages the dynamic swelling behaviour of woven cotton fibres enclosed in a gel matrix in methanol. This strategy achieves simultaneous interfacial self-reinforcement and pressure modulation, enabling the fabrication of fibre-shaped direct methanol fuel cells. These flexible fuel cells operate across a broad temperature range, from –22 °C to 70 °C, showcasing cuttability, water resistance and fast refuelling capabilities, with full refuelling being achieved within 1 min. Furthermore, the fuel cells maintain consistent discharge performance, even after enduring 2,000 continuous flexing cycles. With an energy density of 161.36 Wh kg⁻¹, these fibre-shaped direct methanol fuel cells surpass the energy densities of typical fibre-based power systems. This technology mitigates many of the technical challenges related to the lightweight and flexible application of fuel cells or fuel cell stacks for powering high-energy flexible devices.

Ionogels represent promising materials for thermoelectric generators that efficiently convert low-grade heat into electricity due to their flexibility, stability, nonvolatility, and high thermopower. However, improving their thermoelectric performance presents challenges stemming from the complex interplay between ionic conductivity and thermal conduction. In this study, we developed a highly oriented nanofibrous ionogel membrane through the electrospinning of poly(ethylene oxide) (PEO) blended with a linear CO₂-derived polycarbonate oligomer and an ionic liquid, ethylmethylimidazolium dicyanamide. The ionic liquid facilitated the formation of highly aligned nanofiber structures, which demonstrated superior ionic conductivity and reduced thermal conduction compared to the bulk counterparts, primarily due to the size effect inherent in nanofibers. Additionally, the incorporation of CO₂-derived polycarbonate can increase the amorphous region of the PEO matrix and strengthen the ion-polymer interaction without compromising the orientation of the nanofibers thanks to its compatibility with PEO and its abundance of electron-withdrawing carbonate groups. This strategy effectively decouples ionic conductivity from thermal conduction, thereby enhancing the thermoelectric efficiency of ionogels. This advancement paves the way for the development of nanofibrous ionogels for use in flexible electronics and energy harvesting applications.

Solvents within gels enhance the mobility of polymer chain segments while concurrently diminishing interchain interactions, thereby facilitating the ductility of glassy polymers at the cost of their mechanical strength. Here, we develop a solvent toughening strategy for the preparation of highly compressible and high-strength ionogels in the glassy state. This approach leverages the synergistic effects of the slow dissociation-shift kinetics of solvent ionic liquids and polymer crystallization. Ionogels exhibit an ultimate compressive stress of 2.3 GPa (at 98% compressive strain), toughness of 1219.3 MJ m ⁻³ , and energy dissipation rate of 81.9% (at 70% compression strain). The highly interacting ionic bonds of solvent and the fast crystallization of polymers under load toughen the ionogels and confer impact hardening and efficient energy dissipation behavior under fast impact. A 500-μm-thick ionogel coating can protect fragile items, such as glass, from impact damage. Ionogels, renowned for their impact resistance, hold promise for various applications across industries including human body implants, equipment, transportation, and aerospace.