Sunlight-triggered self-healing of polymers has attractive advantages, but the same illumination inevitably causes photoaging. The resulting properties deterioration and shortened lifespan run counter to the desire for self-healing. Herein, the authors propose an innovative solution by introducing carbazolyl-based dithiocarbamate units. The proof-of-concept crosslinked poly(carbazolyl dithiocarbamates-urethane) shows that the multitasking reactivities of the dynamic bonds stimulated by the sun’s ultraviolet rays concurrently implement self-healing and improve the photoaging resistance. As reflected by the xenon weatherometer measurements, it retains 73.5% of the original strength after 576 h owing to the effects of hydroperoxide intermediates elimination and fluorescence emission. The anti-photoaging ability is far superior to the control filled with commercial stabilizer. Meantime, networks rearrangement via dynamic exchange reactions among the sunlight-sensitive dithiocarbamates and long-range free radicals transfer are allowed in surface layer and the interior, so that the cracks up to 8.5 mm deep are repaired. The work provides a feasible way to break the bottleneck in application of photochemical self-healing polymers.

The miniaturization, integration, and high data throughput of electronic chips present challenging demands on thermal management, especially concerning heat dissipation at interfaces, which is a fundamental scientific question as well as an engineering problem—a heat death problem called in semiconductor industry. A comprehensive examination of interfacial thermal resistance has been given from physics perspective in 2022 in Review of Modern Physics. Here, we provide a detailed overview from a materials perspective, focusing on the optimization of structure and compositions of thermal interface materials (TIMs) and the interact/contact with heat source and heat sink. First, we discuss the impact of thermal conductivity, bond line thickness, and contact resistance on the thermal resistance of TIMs. Second, it is pointed out that there are two major routes to improve heat transfer through the interface. One is to reduce the TIM’s thermal resistance (R_TIM) of the TIMs through strategies like incorporating thermal conductive fillers, enhancing interfacial structure and treatment techniques. The other is to reduce the contact thermal resistance (R_c) by improving effective interface contact, strengthening bonding, and utilizing mass gradient TIMs to alleviate vibrational mismatch between TIM and heat source/sink. Finally, such challenges as the fundamental theories, potential developments in sustainable TIMs, and the application of AI in TIMs design are also explored.

The cathode performance significantly impacts the overall performance of protonic ceramic fuel cells (PCFCs). Many properties of the material, such as oxygen vacancies, protonation, charge carrier transport abilities, and surface oxygen reduction reaction activity, can affect cathode performance. However, which parameter has more weight is still being debated. In this work, we use Ba_0.5Sr_0.5Zr_0.25Fe_0.65X_0.1O₃ as a case study (X = Zn, Cu, Mn, Ni, and Co). First-principle calculations and experimental research are used to study and compare the critical parameters that determine cathode performance. It is discovered that no dopant can improve all the properties of the material. Balancing distinct intrinsic properties is a viable and rational approach. The more balanced, the better performance. When compared to other dopants, nickel dopant is shown to be the most effective in the Ba_0.5Sr_0.5Zr_0.25Fe_0.65X_0.1O₃ material system, allowing a high fuel cell performances of 1862, 1450, and 1085 mW cm^–2 at 700°C, 650°C, and 600°C, with a low polarization resistance of 0.041 Ω cm² at 700°C, which is higher than the majority of cobalt-free cathodes for PCFCs. The current study not only presents a promising cathode candidate, but more importantly, also an effective and fundamental methodology to design cathodes for PCFCs.

The interfacial solar steam generation and water evaporation–driven power generation are regarded as promising strategies to address energy crisis. However, it remains challenging to construct low-cost evaporators for freshwater and electricity co-generation. Herein, we report a salt-assisted carbonization strategy of waste polylactic acid to prepare Hydrangea flower–like graphene and build a bi-functional graphene-based evaporator. The evaporator presents merits of good sunlight absorption, photo-to-thermal conversion property, water transport, good thermal management capability, and negatively charged pores for the continuous diffusion of ions. Hence, it achieves the evaporation rate of 3.0 kg m^–2 h^–1 and output voltage of 0.425 V, surpassing many advanced evaporators/generators. Molecular dynamics simulation result proves that more Na⁺ ions are attracted by functional groups, especially –COOH/C–OH, to promote Na⁺ selectivity in nanochannels. This work offers new opportunities to construct multifunctional evaporators for freshwater and electricity co-generation.

Carbon-based fiber materials are widely used in aerospace, military, and electronics owing to their outstanding comprehensive properties. However, the high degree of crystallization and chemical inertness of their surfaces impede the coloring of such materials by traditional dyeing methods, thereby limiting their application in a broader field. Exploring advanced micro/nano-processing technology for colored carbon-based fiber materials has become a growing interdisciplinary research area in recent years. Therefore, this review comprehensively discusses the structure–color–function relationships of carbon-based fiber materials. The structure of carbon-based fiber materials and their properties responsible for challenges in coloring by traditional dyeing methods are discussed. Moreover, the color-generating mechanisms underlying the display of structural colors by living organisms due to fundamental optical phenomena, including thin/multilayer-film interference, diffraction grating, scattering, and photonic crystals, are described. Furthermore, recent progress in bio-inspirated colored carbon-based fiber materials prepared via advanced micro/nanoscale manufacturing strategies is reviewed. In addition, emerging applications of colored carbon-based fiber materials in various fields are presented. Finally, the possible challenges and future directions for the design, large-scale production, and application of colored carbon-based fiber materials and their composites are discussed, aiming to promote the material design of innovative next-generation systems and research in the advanced material and related engineering fields.

Benefiting from the high sensitivity and electromechanical conversion efficiency, triboelectric nanogenerators (TENGs) are widely used in various fields of self-powered sensing and mechanical energy harvesting, which have great potential for application in future smart Internet of Things. The development of sustainable triboelectric materials with high-performance has a vital impact on the construction of TENG devices that combine high-output performance and environmental friendliness, which have a positive impact on the sustainable development of humanity. This review systematically and comprehensively summarizes the latest research work on TENG’s sustainable materials. First, an overall overview is provided based on the composition of the materials, including amino acids, polysaccharides, and synthetic polymer, and the representative research works are further classified and summarized in detail. In addition, the latest research progress of TENG with sustainable materials in the fields of self-powered sensing and mechanical energy harvesting applications is also summarized. Finally, the overviews are provided for the various challenges in the current development of TENG’s sustainable material, and the related outlooks are offered on the corresponding development strategies and directions of this field in the future.

Polymer nanofibers exhibit unique nanoscale effects, high specific strength and modulus, exceptional design flexibility, large aspect ratios, and substantial specific surface areas. These characteristics have drawn significant attention in emerging fields such as flexible electronics, 5G communications, and new energy vehicles. Notably, poly(p-phenylene benzobisoxazole) nanofibers (PNFs) present the best thermal stability and flame retardancy among all known polymer nanofibers. Furthermore, due to the highly oriented molecular chains and orderly structure, PNFs demonstrate superior thermal conductivity compared to conventional polymer nanofibers, thus garnering significant attention and favor from researchers. This paper summarizes the latest research progress of PNFs, detailing three preparation methods (electrospinning, mechanical dissociation, and protonation) along with their respective advantages and disadvantages. It also elucidates the current development status of PNFs in applications such as flame retardancy, thermal conduction, electrical insulation, electromagnetic shielding, and battery separators, and discusses the challenges and prospects faced by PNFs. This paper aims to provide theoretical guidance for the preparation and application of PNFs, enhancing their potential in advanced applications, and further expanding their application scope.

The development of efficient and robust non-Pt and low-Pt catalysts with equivalent or even superior performance to commercial Pt-based catalysts for hydrogen evolution reaction (HER) is highly desired, but challenging, in the field of water electrolysis. Herein, we report a facile and cost-effective in situ electrochemical approach for the synthesis of atomically dispersed metal sites including platinum (Pt), ruthenium (Ru), and palladium (Pd) on the polyaniline (PANI) support. The PANI exhibits not only high electrochemical conductivity but also efficient H⁺ capture from hydronium ions, leading to the formation of protonated amine groups that can be easily electrochemically reduced to H₂ on atomically dispersed metal active sites. As an example, the atomically dispersed Pt sites anchored on carbon cloth-supported PANI (PANI-Pt/CC) demonstrate excellent activity and durability toward the HER. The mass activity of PANI-Pt-10/CC reaches 25 A mg_Pt^–1, exhibiting a significant enhancement of 50-fold compared to that of the commercial Pt/C (0.5 A mg_Pt^–1). Therefore, this study presents a universally applicable approach for the design of atomically dispersed metal sites/conducting polymer heterostructures for highly efficient catalysts toward HER and beyond.

The capacity of biological tissues to undergo self-healing is crucial for the performance of functions and the continuation of life. Conventional intrinsic self-healing materials demonstrate analogous functionality depending on the dissociation-recombination of reversible bonds with no need of extra repair agents. However, the trade-off relationship between mechanical strength and self-healing kinetics in intrinsic self-healing systems, coupled with the lack of additional functionality, restricts their service life and practical applications. Diversified highly ordered structures in organisms significantly affect the energy dissipation mechanism, signal transmission efficiency, and molecular network reconstruction capability due to their multi-dimensional differentiated macroscopic composite constructions, microscopic orientation textures, and topologies/bonding types at molecular level. These architectures exhibit distinctive strengthening mechanisms and functionalities, which provide valuable references. This review aims at providing the current status of advanced intrinsic self-healing materials with biomimetic highly ordered internal micro/nanostructures. Through highlighting specific examples, the classifications, design inspirations, and fabrication strategies of these newly developed materials based on integrating dynamic interactions with ordered nano/microstructures are outlined. Furthermore, the strengthening and self-healing balance mechanisms, structure–functionalization relationships, and potential application values are discussed. The review concludes with a perspective on the challenges, opportunities, and prospects for the development, application, and promotion of self-healable materials with bio-like ordered architectures.

Ionic conductive hydrogels (ICHs) prepared from natural bioresources are promising candidates for constructing flexible electronics for both commercialization and environmental sustainability due to their intrinsic characteristics. However, simultaneous realization of high stiffness, toughness, conductivity, and multifunctionality while ensuring processing simplicity is extremely challenging. Here, a poly(ionic liquid) (PIL)-macromolecule functionalization strategy within a NaOH/urea system is proposed to construct high-performance and versatile polysaccharide-based ICHs (e.g., cellulosic ICHs). In this strategy, the elaborately designed “soft” (PIL chains) and “hard” (cellulose backbone) structures as well as the dynamic covalent and noncovalent bonds of the cross-linked networks endow the hydrogel with high mechanical strength (9.46 ± 0.23 MPa compressive modulus), exceptional stretchability (214.3%), and toughness (3.64 ± 0.12 MJ m^–3). Ingeniously, due to the inherent conductivity, design flexibility, and functional compatibility of the PILs, the hydrogels exhibit high conductivity (6.54 ± 0.17 mS cm^–1), self-healing ability (94.5% ± 2.0% efficiency), antibacterial properties, freezing resistance, water retention, and recyclability. Interestingly, this strategy is extended to fabricate diverse hydrogels from various polysaccharides, including agar, alginate, hyaluronic acid, and guar gum. In addition, multimodal sensing (strain, temperature, and humidity) is realized based on the stimulus-responsive characteristics of the hydrogels. This strategy opens new perspectives for the design of biomass-based hydrogels and beyond.

The energy generation performance of triboelectric materials under ultrahigh pressure remains to be investigated. Here, the variations in molecular structure and built-in electric field of triboelectric polymers under ultrahigh pressure have been thoroughly studied. The attenuation of built-in electric field and the escaping of triboelectric charges under ultrahigh pressure are observed in different triboelectric polymers, whereas the existence of deep traps allows the built-in electric field to be recoverable with the release of pressure. Moreover, the macromolecular conformational changes, including twisting molecular chains and crystal structure changes, can also induce the redistribution of deep traps, leading to a sudden increase in built-in electric field under specific pressure. Finally, a triboelectric sensor for ultrahigh pressure condition is fabricated with excellent cycle repeatability and a total thickness of 2 mm, which has a sensitivity of 0.07 V MPa^–1 within a linear region of 1–100 MPa. This study offers in-depth insight into the physical understanding of charge behavior both on interface and in bulk of triboelectric materials, whereas the proposed ultrahigh pressure sensors can promote various potential applications of triboelectric sensor in extreme environments.