Abstract Low-grade heat (<373 K) remains an underutilized energy source due to inefficient conversion technologies. While ionic thermoelectric (i-TE) materials show promise for direct thermal-to-electrical energy conversion, simultaneously optimizing the conductivity and Seebeck effect remains a significant challenge. In this work, we proposed an ionic liquid [BMIM]Cl-assisted cellulose ionogel composited with single-walled carbon nanotubes (SWCNTs). [BMIM]+ adsorbed onto SWCNT surfaces effectively promotes uniform dispersion of SWCNTs in Cl–-mediated cellulose dispersion, thereby optimizing the microporous structure of the ionogel for enhanced ion transport. Moreover, [BMIM]+ induces free electrons within the SWCNT network to gather and create strong ion-electron coupling for synergistic cotransport. These combined effects enable rapid thermal-diffusion-driven ion transport, endowing the ionogel with remarkable ionic conductivity (34.6 mS cm–1), Seebeck coefficient (26.33 mV K–1), and thermoelectric figure of merit (2.58). Furthermore, the ionogel exhibits remarkable versatility for wearable multimode sensing and physiological monitoring. This work provides a scalable strategy for designing multifunctional, high-efficiency i-TE systems.

The physical eradication of bacterial biofilms is fundamentally limited by rapid post-treatment regeneration. A strategy that integrates physical destruction with biological suppression is therefore highly coveted. Herein, we introduce a strategy to chemically reprogram magnetic liquid metals (LMs) into intelligent antibiofilm nanocomposites. Through a one-step metal-phenolic coordination, we coat the LM with a natural polyphenol (baicalin, BA), creating a nanoplatform (MBA) that executes a synergistic "destroy-and-pacify" mission. This design establishes a self-reinforcing loop: magnetic actuation provides the mechanical force to breach the biofilm matrix, enhancing the penetration of the BA coating. Concurrently, the BA-mediated inhibition of quorum sensing and EPS synthesis pre-weakens the biofilm, making it more susceptible to physical ablation. This reciprocal potentiation leads to exceptional efficacy, more than doubling the clearance efficiency of mature P. aeruginosa biofilms on implants in a murine model and achieving a level of eradication unattainable by monotherapies. This work establishes a new paradigm for designing smart theranostic microrobots, paving the way for programmable platforms to tackle complex biological barriers.

Polydopamine-based melanin-like materials have been widely used in the fields of ultraviolet(U V)shielding,solar desalination and an-ti-inflammatory treatment owing to their unique physical properties.The well-established synthesis of polydopamine nanoparticles involves the oxidative polymerization of dopamine-derived monomers,resulting in cross-linked nanostructures with high complexity and heterogeneity.Therefore,the controlled synthesis of polydopamine-based melanin-like materials with well-defined structures and predictable properties re-mains challenging.Herein,we propose a mechanochemical Suzuki polymerization approach for the synthesis of linear melanin-like polymers with tunable physical properties.Compared with polydopamine nanoparticles,the mechanochemical approach offers a more flexible chain-like structure,thereby enhancing its antioxidant performance.Furthermore,this approach also enables the preparation of a melanin-like alternating copolymer that exhibits green fluorescence owing to its π-conjugated structure.This study not only offers opportunities for exploring novel syn-thetic melanin materials,but also provides new insights into the structure-function relationships of polydopamine-based materials.

Thermal softening is an inevitable process in the physical network. Polyurethane (PU), a typical commercial material, is constructed by physical networks, which undergoes the serious thermal decay on mechanical properties at high temperature. Herein, a physically cross-linked PU with a unique thermal stiffening behavior has been developed by incorporating B-N coordination with reversible B-O bonds. The B-N coordination can significantly improve the mechanical properties of the PU. The reversible B-O bonds (temperature dependent reversible transformation between B-OH and B-O-B) are conducive to constructing more multi-coordination macromolecular crosslinking points and more stable B-N coordination bonds at high temperature, endowing the PU with the special thermal stiffening behavior for the first time. Such thermal stiffening behavior compensates for the bond breakage and the network destruction caused by heat, significantly expands the rubbery plateau and delays the entire chain motion of the thermoplastic PU. As a result, the terminal flow occurs at a higher temperature up to 200°C. The modulus retention ratio of the materials is up to 87

Smart antibacterial coatings with surface-independent methods, on-demand antibiotic release, and real-time drug loading monitoring capabilities have attracted increasing interest in the fields of medical devices, antibiotics delivery platforms, and implantable devices. Addressing the complexity inherent in existing methods, this work innovates by simplifying the synthesis process and integrating aminoglycosides with metallosupramolecules to develop versatile and effective coatings. These coatings not only exhibit exceptional biological activity and efficient antibacterial properties both in vitro and in vivo, but also enable high drug loading and controlled release. Significantly, their application across various devices has demonstrated profound therapeutic effects in treating implant infections and promoting bacterial wound healing. A key advancement of these coatings is the integration of color-changing indicators for real-time monitoring of drug levels, enhancing the precision of wound care, and facilitating timely clinical interventions. This research marks a significant stride in the development of more accessible, bioactive, and smart antibacterial materials, opening new avenues in the field of smart medical coatings. A series of antibacterial coatings combining aminoglycosides with metallosupramolecules has been developed. These coatings show excellent antibacterial activity in vitro and in vivo, featuring high drug loading and controlled release. They improve therapeutic outcomes for implant infections and bacterial wounds. Additionally, a real-time drug release monitoring system enhances wound care precision and enables timely clinical interventions. image

Exploring novel healing mechanisms is a constant impetus for the development of self-healing materials. Herein, we find that side-chain interlocking of bottlebrush polymers can form a dynamic network and thereby serve as a driving force for the self-healing process of the materials. Molecular dynamics simulation indicates that the interlocking is formed by the interpenetration between the long side chains of adjacent molecules and stabilized by van der Waals interactions and molecular entanglements of side chains. The interlocking can be tailored by changing the length and density of the side chains through atom transfer radical polymerization. As a result, the optimized bottlebrush polymer shows a healing efficiency of up to 100%. Unlike chemical interactions, side-chain interlocking eliminates the introduction of specific chemical groups. Therefore, bottlebrush polymers can even self-heal under harsh aqueous conditions, including acid and alkali solutions. Moreover, the highly dynamic side-chain interlocking enables bottlebrush polymers to efficiently dissipate vibration energy, and thus they can be used as damping materials. Collectively, side-chain interlocking expands the scope of physical interactions in self-healing materials and hews out a versatile way for polymers to accomplish self-healing capability in various environments.

Integrating mechanical robustness with efficient healability under mild conditions is an inevitable requirement for the commercial development of self-healing ionomers. This work reveals that the resonance isomerization effect can be adopted to construct vigorous ionic networks in ionomers. As a proof of concept, 4-(alkylamino) pyridine (DMAP) and its derivatives are selected to react with bromobutyl rubber (BIIR) to fabricate BIIR ionomers. The ionized DMAP moieties manifest a resonance isomerization effect, leading to stronger ionic interactions, larger regular ionic aggregations, and more obvious microphase separation. Benefiting from the resonance isomerization effect, the BIIR ionomers in our work possess superior tensile strength (21 MPa) and toughness (92 MJ/m3), exceeding those of the existing BIIR-based materials. Moreover, the plasticizing effect of the alkyl substituent group on the DMAP-based derivatives can be further used to tailor the ionic cluster relaxation, thereby overcoming the compromise between mechanical performance and self-healing ability. Despite the dynamic network, the self-healing BIIR ionomers show a high gas barrier property which is very close to that of covalently crosslinked BIIR, enabling their potential to be used in next-generation repairable automobile tires. This work will expand the toolbox of ionic bond chemistry and afford an effective molecular design approach for optimizing mechanical and self-healing properties simultaneously.

The band offsets of heterojunctions formed between indium tin oxide (ITO) and amorphous gallium oxide (a-GaO x ) of different stoichiometric ratios were measured by x-ray photoelectron spectroscopy using the Kraut method. a-GaO x films with different stoichiometric ratios were deposited on commercial ITO/quartz substrates using radio frequency magnetron sputtering by varying the Ar/O 2 flux ratio. With the increase of oxygen flux in the reaction gas, the oxygen vacancy (V O ) concentration of a-GaO x decreases and its bandgap increases from 5.2 eV to 5.32 eV, while the valence band offset of ITO/a-GaO x heterojunction changes from 0.29 ± 0.07 eV to −0.74 ± 0.06 eV and conduction band offset changes from 0.95 ± 0.085 to 2.10 ± 0.075 eV. The results indicate that the band alignment of ITO/a-GaO x heterojunction can change from type I to type II with the variation of Ga/O stoichiometric ratio, which can provide guidance for the design of their corresponding high-performance heterostructured devices.

Surgical masks are crucial personal protective equipment to prevent and suppress the transmission of highly infectious viruses, especially suffered from some pandemic outbreaks. However, due to the lack of sterilization functions, the long-term reused masks become the hotbed of microorganisms and further cause additional damages to human health. Furthermore, it is desirable to endow multifunctionalities to the masks, such as self-powered real-time respiratory monitoring to forecast breath-related diseases. Although many efforts have been made towards those requirements, the complicated surface engineering process and involved extra weight of these mask still brought adverse effects in high respiratory resistance and poor wearing comfortability. In this work, we reported a facile fabrication strategy towards multifunctional masks based on the surface modification of melt-blown cloth by two kinds of bioinspired coatings. After sequentially performed mussel-inspired polydopamine coating and metal-phenolic network (Fe3+ and gallic acid) coatings, the obtained masks not only maintained the features of light, flexibility, breathability and filterability, but also realized the self-sterilization under the sunlight irradiation, thus allowing the facile reutilization for many times. Moreover, benefiting from the wet electricity generated by carboxyl group of gallic acid, the modified mask could effectively monitor the different respiratory status in real time. It was anticipated that this work can provide a new strategy towards the multifunctional integration of next-generation masks.

Elastomers easily undergo a catastrophic failure as soon as a crack is introduced by mechanical damage. Thus, it is extremely important for elastomers to possess fast healing ability, which enables the quick reparation of cracks. However, developing elastomers with fast self-healing ability and high mechanical strength is highly challenging. Herein, we fabricate a metallosupramolecular elastomer by facilely introducing pyridine-Cu coordination into a copolymer of ethyl acrylate and vinyl pyridine. Interestingly, the pyridine-Cu coordination has a strong photothermal effect, which readily increases the sample temperature to 60°C in 30 s under near-infrared light. At this temperature, the sticky reptation modes are activated and thus serve as the driving force for network reorganization and fast self-healing of the metallosupramolecular elastomer. Albeit with a tensile strength of 10 MPa, the scratched and completely fractured samples can be healed within 2 min and 3 h, respectively. Moreover, during the damage and healing processes, the break and reformation of the coordination bonds can be tracked through laser confocal micro-Raman spectroscopy. This provides a microscopic methodology to monitor the bond-level healing kinetics of metallosupramolecular polymers.

Self-healing elastomers, featured by their ability to recover their mechanical properties and/or functions after being damaged, hold great potential for prolonging the service life and improving the reliability of vehicles, spacecraft, lithium batteries, soft robotics, and wearable devices. Therefore, self-healing elastomers have become the sought-after smart materials in recent years. This chapter reviews the recent progress in self-healing elastomers and their composites based on different dynamic networks. The design concepts, healing mechanisms, and diversified properties of different self-healing elastomers are discussed. The existing dilemma, corresponding solution, and development prospects of self-healing elastomers are also included in the last part of this chapter.

In this work, CdS thin films were deposited on glass/fluorine-doping tin oxide (FTO) substrates by low-cost chemical bath deposition (CBD), followed by annealing with CdCl2-doping (Cl-doping) to fabricate resistive-type photodetectors (PDs) with a vertical structure of glass/FTO/CBD-CdS:Cl/electrode. The effect of annealing with Cl-doping (AwCl) on the various properties of films and the photodetection performance of PDs were systematically characterized by special testing methods. The results revealed that the surface morphology and crystal structure of CBD-CdS:Cl films were improved, accompanied by an enhancement of hexagonal phase (002) crystal plane (wurtzite structure), and the optical bandgap of films can be adjusted between 2.43 and 2.26 eV while the electron activation energy of the films was reduced from 75.9 to 10.3 meV after AwCl. Furthermore, the light responsivity of CBD-CdS:Cl PDs were 0.57, 0.59 and 1.67 A/W under 365, 400 and 530 nm illumination at a bias of −2.0 V, respectively, and the detectivity of photons at corresponding wavelengths were 3.7 × 108, 3.9 × 108 and 1.08 × 109 Jones. Meanwhile, the PDs showed optimized repeatability and improved sensitivity under periodic illumination. The above results demonstrated that the CBD-CdS:Cl PDs with a vertical structure developed in this work had good detection performance at certain characteristic wavelengths.

A quartz crystal resonator (QCR) is an indispensable electronic component in the field of the modern electronics industry. By designing and depositing electrodes of different shapes and thicknesses on a quartz wafer with a certain fundamental frequency, the desired target frequency can be obtained. Affected by factors such as the deposition equipment, mask, wafer size and placement position, it is difficult to accurately obtain the target frequency at a given time, especially for mass-produced QCRs. In this work, a laser with a wavelength of 532 nm was used to thin the electrodes of a QCR with a fundamental frequency of 10 MHz. The electrode surface was etched through a preset processing pattern to form a processing method of local thinning of the electrode surface. At the same time, the effect of laser etching on silicon dioxide and resonator performance was analyzed. Satisfactory trimming frequency-increasing results were achieved, such as a frequency modulation accuracy of 1 ppm, frequency distribution with good consistency and equivalent parameters with small changes, by the laser partial etching of the resonator electrode. However, when the surface electrode was etched into using through-holes, the attenuation amplitude of the equivalent parameter became larger, especially in terms of the quality factor (Q), which decreased from 63 K to 1 K, and some resonators which had a serious frequency drift of >40%. In this case, a certain number of QCRs were no longer excited to vibrate, which was due to the disappearance of the piezoelectric effect caused by the local thermal phase change in the quartz wafer.

In this study, bromide-iodide lead perovskite (CH3NH3Pb(I1-xBrx)(3)) thin films were fabricated and applied as copper-free back contact layers for CdTe solar cells. The results reveal that the open-circuit voltage (V-oc) and fill factor (FF) of the CdTe solar cells are greatly enhanced by the utilization of perovskite back contact layers. This is mainly due to the evidently reduced charge transportation barrier at the back contact, which is verified by temperature-dependent current-voltage (J-V-T) and apparent quantum efficiency (AQE) measurements. Specifically, after the application of perovskite back contact layer, the best-performing device shows 15.80% improvement in efficiency (from 10.82 to 12.53%), with V-oc and FF increasing by 3.94% and 6.91%, respectively. Besides, the overall uniformity of the solar cells is also improved by the perovskite back contact, suggested by laser beam induced current (LBIC) results. Further simulation results confirm the experimental results and clarify the optimized cell performance by perovskite back contact layer in terms of both energy band alignment and charge carriers' recombination. In addition, in the simulation section, we have also investigated the effect of the bandgap, thickness and doping level of perovskite and the doping level of CdTe on the cell performances. The experiments and the numerical simulation reported in this work suggest perovskite a potential copper-free back contact layer for the fabrication of efficient CdTe solar cells.

A universal method to study the self-healing kinetics and its underlying sticker-reorganization mechanism for ionomers containing AIEgens as sticky groups.

Dynamically crosslinked materials generally lose their self-healing ability and mechanical robustness in aqueous, acidic, and basic environments due to disruption of their dynamic interactions and bonds. Herein, a micelle-like structure with a hydrophobic outer layer is used to protect ionic interactions. This structure ensures the self-healing and long-term stability of the ionically crosslinked elastomers in aqueous, acidic, and basic environments. The elastomer possesses a tensile strength of 6.7 MPa and a strain at break of 1400%, which is superior to the existing waterproof self-healing elastomers. The strain sensors and dielectric actuators based on the elastomer are highly stable and self-healable, even in extremely harsh environments. This design strategy of hydrophobic protection for dynamic interactions is quite general, allowing it to be extended to other self-healing materials.

While most self-healing elastomers are mechanically weak, using the most commonly used carbon black (CB) to reinforce self-healing elastomers has not been reported. The possible reason is that the introduction of carbon black will cause complex changes in molecular dynamics, which leads to unpredictable self-healing effects. Herein, carbon black is introduced into a self-healing ionomer based on brominated butyl rubber (BIIR) grafted with tert-butyl pyridine (BP). Interestingly, the hierarchical microstructure and multilevel molecular dynamics of ionomers are well regulated by the strong interfacial π-cation interactions between CB and ionic aggregates. The strong interfacial interaction leads to high content of bound rubber, uniform dispersion of CB and compact physical network. Although such structural change has negligible influence on the segmental motion, it enhances the relaxation time and activation energy of ionic clusters, and thus endows the ionomer with high mechanical properties. Meanwhile, the structural change leads to higher relaxation temperature, thereby increasing the self-healing temperature. Despite this fact, the healing efficiency can still be regulated between 50% and 100%, depending on the filler content and temperature. Moreover, the CB reinforced ionomer is re-processable and recyclable. This study demonstrates that CB reinforcement is feasible to improve the mechanical properties of self-healing elastomers.

A class of multi-skin-function mimetic bottle-brush elastomers with the integration of strain-adaptability, self-healing ability, breathability and ultra-sensitivity.

Elastomeric vitrimers with covalent adaptable networks are promising candidates to overcome the intrinsic drawbacks of conventional covalently-crosslinked elastomers; however, most elastomeric vitrimers show poor mechanical properties and require the addition of exogenous catalysts. Herein, we fabricate a catalyst-free and mechanically robust elastomeric vitrimer by constructing a segregated structure of sodium alginate (SA) in the continuous matrix of epoxidized natural rubber (ENR), and further crosslinking the composite by exchangeable hydroxyl ester bonds at the ENR-SA interfaces. The manufacturing process of the elastomeric vitrimer is facile and environmentally friendly without hazardous solvents or exogenous catalysts, as the abundant hydroxyl groups of the segregated SA phase can act as catalyst to activate the crosslinking reaction and promote the dynamic transesterification reaction. Interestingly, the segregated SA structure bears most of the load owing to its high modulus and small deformability, and thus ruptures preferentially upon deformation, leading to efficient energy dissipation. Moreover, the periodic stiffness fluctuation between rigid segregated SA phase and soft ENR matrix is beneficial to the crack-resisting. As a result, the elastomeric vitrimer manifests exceptional combination of catalyst-free, defect-tolerance, high tensile strength and toughness. In addition, the elastomeric vitrimer also exhibits multi-shape memory behavior which may further broaden its applications.

Due to the dynamic nature of networks and high mobility of molecular chains, self-healing elastomers are usually confronted with the trade-off between self-healing efficiency and mechanical properties. Herein, a self-healing ionomer with both high mechanical performance and high self-healing efficiency has been successfully developed by grafting bromobutyl rubber (BIIR) with pyridine-based derivatives. Interestingly, the substituents on the pyridine ring can be used to regulate the interaction forces of ionic clusters and molecular dynamics. The electron-donating effect of the substituents facilitates stable π-π stacking between pyridyl ions, inducing the formation of regular and large ion aggregates, thereby improving the mechanical strength of the ionomer. Meanwhile, the plasticizing effect of the substituents reduces the activation energy and relaxation temperature of the ionic aggregates, thus endowing the ionomer with a high self-healing efficiency. As a result, the ionomer shows tensile strength as high as 8.1 ± 0.3 MPa under room temperature and self-healing efficiency of 100 ± 3% at 60 °C. Therefore, this strategy can be easily extended to other halogen-containing polymers, leading to a novel class of self-healing ionomers that hold great promise in diverse applications.