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[Display omitted] • The constructed similar structure reduces binding energy between MXene and PU. • 120 °C is achieved under two suns through synergistic photothermal effect. • MXene-TT/PU shows a large reduction of 47.06% in peak heat release rate. • Flame retardancy mechanism is revealed through molecular dynamic simulation. MXene, renowned for its exceptional metallic conductivity, thermal conductivity, and tunable surface chemistry, has shown great potential for various applications in energy storage, catalysis, electromagnetic shielding and photothermal conversion. However, the inherent inorganic nature of MXene poses a significant challenge in excavating its potential when incorporated into organic polymer matrix. Herein, we develop an interface engineering strategy to functionalize the surface chemistry of MXene via in-situ polymerization of tannic acid and toluene diisocyanate (TA and TDI, abbreviated as TT), protecting the MXene from oxidation while enhancing the interface compatibility between MXene and polyurethane (PU). MXene-TT/PU with high machinability, processibility and thermal stability is achieved through the urethane groups interactions from MXene-TT and PU, which shows a large reduction of 47.06% in peak heat release rate and 24.53% in peak total heat release, respectively. The mechanism of greatly improved flame retardancy is revealed by Molecular dynamic simulations. Moreover, MXene-TT/PU also exhibits rapid photothermal de-icing under simulated solar irradiation, with the surface ice begin to thaw in ∼30 s. This design concept, which is based on similar molecular structures, provides an effective approach to address the interfacial and stability issues associated with MXene, thereby enhancing its flame retardancy, mechanical properties, and photothermal de-icing capabilities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Facile fabrication of self-healing, conductive ionogels with enhanced bonding. • Exceptional adhesion and mechanical properties in transparent ionogels. • Recyclable ionogels enabled sustainable flexible electronics. • Tailored ionogel devices meet high-performance flexible electronics demands. Self-adhesive intelligent flexible devices have opened a plethora of innovative possibilities for interfacial flexible electronics, including specific applications such as bioelectronic interfaces, flexible displays, and wearable devices. However, establishing reliable interfaces between inherently incompatible or immiscible soft materials remains a critical challenge for achieving dependable performance of interfacial flexible devices. Here, we employ a facile and generic in-situ photopolymerization method for fabricating imidazolium-based ionogels with intrinsically conductive, self-healing properties, enabling enhanced interfacial bonding. Our approach yields ionogels with exceptional properties, including robust adhesion (∼477 kPa), ultrahigh elasticity (∼1837% elongation), remarkable mechanical toughness (tensile and compressive strength of ∼1703 kPa and 12182 kPa, respectively), and high transparency (∼92% transmittance). Notably, our ionogels demonstrate great potential as sustainable flexible electronics with excellent recyclability. We develop a range of customizable devices with personalized structures, utilizing a combination of 3D printing, mold casting, and in-situ photocuring. Furthermore, the intrinsically conductive ionogel can serve as smart wearable sensors for real-time monitoring of human movements. Our work unlocks the potential for innovatively designing customizable ionogel devices with integrated functionalities that fulfill the mounting demand for high-performance interfacial flexible electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] Conductive hydrogels are essential for enabling long-term and reliable signal sensing in wearable electronics due to their tunable flexibility, stimulus responsiveness, and multimodal sensing integration. However, developing durable and dependable integrated hydrogel-based flexible devices has been challenging due to mismatched mechanical properties, limited water retention capability, and reduced flexibility. This work addresses these challenges by employing a tailored physical–chemical dual-crosslinking strategy to fabricate dynamically reversible organo-hydrogels with high performance. The resultant organo-hydrogels exhibit exceptional characteristics, including high stretchability (up to ∼495% strain), remarkable toughness (with tensile and compressive strengths of ∼1350 kPa and ∼9370 kPa, respectively), and outstanding transparency (∼90.3%). Moreover, they demonstrate excellent long-term water retention ability (>2424 h, >97%). Notably, the organo-hydrogel based sensor exhibits heightened sensitivity for monitoring physiological signals and motions. Furthermore, our integrated wireless wearable sensing system efficiently captures and transmits various human physiological signals and motion information in real-time. This research advances the development of customized devices utilizing functional organo-hydrogel materials, making contributions to fulfilling the increasing demand for high-performance wireless wearable sensing. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D-printed structure imparts higher solar absorption and salt-resistance ability. • Flower-like Co 3 O 4 significantly enhances the solar absorption and conversion. • High solar steam generation rate is achieved in one sun illumination. • The light trapping effect is enhanced by the hierarchical structure. Compared with conventional two-dimensional (2D) structure, three-dimensional (3D) solar steam generators have presented a considerably higher evaporation rate due to their structure superiority. As an emerging field, 3D printing technology has been attached by significant attention due to its feasibility and designability in the fabrication of micro-nano structures. Herein, inspired by natural light-trapping structures, a novel hierarchical structure assembled from flower-like cobalt tetroxide and 3D-printed stent is prepared. Based on the geometrical light trapping effect, both the flower-like structure in cobalt tetroxide and the hollow morphology in 3D-printed stent can significantly enhance the solar absorption and conversion efficiency through multiple reflection-incidence processes. Since the wetting direction in the cylindrical structure is always from the edge to the center, there will be a large number of salt particles at the edge of the cylinder falling by the virtue of gravity, thus achieving a high salt tolerance, and this process is illustrated by molecular dynamics simulation. Along with the rapid photo-thermal response in the solar spectrum, this 3D-printed hierarchical structure coated with flower-like cobalt tetroxide has achieved a high steam generation rate of 2.028 kg m-2h−1 under one sun irradiation (1.0 kW/m2) and excellent decontamination ability for organic dye-containing solution. Meanwhile, the desirable steam generation rate can maintain an average value of more than 1.8 kg·m-2h−1 for long time. This 3D-printed solar evaporator is highly efficient and salt-tolerant, attributed to the enhanced geometrical light-trapping and artificial channel-array structure, presenting an effective solution for enhancing solar absorption and conversion. [ABSTRACT FROM AUTHOR]

Taking into consideration the frigid and thunderstorms, the flame retardancy and de-icing performance are simultaneously desiderated for some open-air key equipment, such as air fuselage and wind turbine blades. Here, inspired by the anti-reflection phenomenon of moth eyes and cicada wings, a multi-functionalized and biomimetic MXene@SnO 2 hierarchical nanostructure is prepared to effectively impart flame retardancy and solar de-icing performance to thermoplastic polyurethane (TPU) resin used widely as the finishing coat of protective materials of open-air equipment. Based on the catalytic effect and barrier function, the addition of hierarchical MXene@SnO 2 nanostructures also effectively decreases the release of heat and toxic smoke from PU resin, as confirmed by reductions of 50.5% and 33.1% in the peak heat release rate and smoke production rate, respectively. Due to the appropriate refractive index, the light reflection phenomenon is effectively suppressed, thus promoting solar absorption (∼90% at 0.4 mm film) and photo-thermal conversion (∼74.2 °C with simulated solar illumination of 1.0 kW/m2) in TPU-MXene@SnO 2 nanocomposites. Within the environment of −20 °C, the surface temperature of TPU-MXene@SnO 2 nanocomposites is still up to 32.7 °C and the surface ice pellet begins to melt at ∼40s, much earlier than 600s of pure TPU resin. In addition, the practical application of functionalized TPU nanocomposites is further improved by the higher mechanical properties, attributed to the strong interfacial interaction. Inspired by moth eyes and cicada wings, flame retardancy and solar de-icing performance are first integrated into polymer materials, thus effectively promoting their application in some extreme environments. [Display omitted] [ABSTRACT FROM AUTHOR]

During milling, brittle fracture occurs in SiCp/Al composites due to extrusion, while plastic deformation occurs in the aluminum matrix. The damage of particles and the matrix is different. In order to observe the brittle fracture process of particles more accurately, a single particle milling model was established to analyze the damage and deformation of particles when cutting along different positions. In the study of the influence of cutting speed on particle failure, a two-dimensional simulation model with multi-particle random distribution was established. Keeping the cutting depth the same, only the cutting speed was varied to study its effect on the surface quality. Detailed analysis of the orthogonal test results shows that the influence on surface quality is from feed rate, milling speed, and milling depth in descending order. The optimal cutting conditions are milling speed of 47.10 m/min, feed speed of 10 mm/min, and cutting depth of 80 μm. Through the analysis of sub-surface morphology, the main causes of cracks, pits, and other defects on machined surfaces can be explained, and the experimental results are proved to be the same as the simulation results. [ABSTRACT FROM AUTHOR]

[Display omitted] • A flame-retardant and photo-thermal microstructure is synthesized. • Thermochromic materials and bio-based flame retardants are used as core and shell. • Heat release and smoke production are effectively suppressed. • The melting and slide of ice block is accelerated by solar-thermal conversion. Due to the extreme dynamic weather, important industrial facilities and infrastructure providing vital support for people's lives usually face the hazards of fire and icing, especially in the weather of thunderstorm and ice. Therefore, to further establish a safe community, we develop a dual-functional polyurea (PUA) coating used as protective materials by introducing flame retardancy and solar de-icing performance. Based on the microencapsulation and electrostatic self-assembly technologies, flame-retardant and thermochromic microcapsules (TCM) are firstly prepared and then added into PUA resin, by using melamine resin and bio-based phytic acid/chitosan (PA/CS) hybrids as double-shell materials. The high phosphorus content of PA and the carbon-forming effect of CS together play a synergistic flame retardant effect, not only improving the thermal stability of microcapsules but also enhancing the flame retardant property of PUA coating. In the cone calorimetry test, the ignition time of TCM@PA/CS@PUA-3 is longer, and the pHRR is reduced by 19.93 %, which shows the improvement of flame retardant performance. Due to the thermochromic mechanism, TCM@PA/CS@PUA composite coatings are able to adjust the photo-thermal conversion ability according to different environment temperature, achieving less temperature in hot environment and higher temperature in cold environment. The excellent photo-thermal conversion ability also promotes the ice melting and slide in 525 s. This polyurea composite coating with both flame retardant and de-icing properties shows great potential for maintaining the normal operation and safety of outdoor industrials and infrastructure in extremely dynamic weather conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • This work focuses on the sustainability and safety of radiative cooling materials. • Bio-based chitosan and phytic acid are used to prepare radiative cooling film. • The radiative cooling effect and fireproof performance are presented simultaneously. Even though significant advantages in the energy-free regulation of temperature are presented, the practical applications of radiative cooling materials in buildings and human surfaces still involve many safety issues, especially for fire hazards of polymer-based materials. Meanwhile, renewable and environmentally friendly materials are urgently needed to develop suitable radiative cooling materials with no adverse environmental impact. Herein, a chitosan-derived composite aerogel film with high solar reflection provided by the addition of melamine-phytic acid (MA/PA) hybrids is designed and prepared, presenting radiative cooling and fireproof performances. The instinct deep-yellow color of chitosan (CS) is successfully shielded by high-reflective MA/PA hybrids, while IR emissivity of up to 90.4 % and solar reflectivity of ∼ 89.3 % are achieved. In outdoor environments, this composite aerogel shows sub-ambient temperature drops of ∼ 4.3 °C and ∼ 3.1 °C in cloudless and cloudy weather, presenting a robust cooling effect. In addition, CS-MA/PA composite aerogel film with 3 mm thickness can isolate the fire of ∼ 500 °C, showing superior fire safety attributed to the synergistic flame retardant effects among chitosan, phytic acid, and melamine, which suppress the initial growth of fire and promote the rapid formation of protective char layer. This work provides a bio-based, fire-safe, and radiative cooling material to decrease the energy consumption of temperature regulation with a more environmentally friendly and safer approach, further promoting the practical application of radiative cooling materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The free switch of passive radiation cooling and solar thermal conversion is realized. • An average temperature drop of ∼5.62 °C is achieved under the hot environment. • A temperature increase of 28.3 °C is achieved under the cold environment. • The fire hazards of materials designed are suppressed significantly. Seasonable and spontaneous replacement approach of daytime radiative cooling to solar thermal conversion is challenging yet imperative for year-round thermal management materials. Meanwhile, the fire safety of thermal management materials is extremely important but often overlooked. Herein, we report a bio-inspired and fireproof aerogel presenting dynamically self-switchable ability of daytime radiative cooling and solar thermal conversion, composed of thermochromic microcapsules (TC), boron nitride nanosheets (BN), and bio-based materials (alginate and phytate). In hot environments, TC/BN composite aerogel shows solar reflectivity of 91.8 % and IR emissivity of 84.3 %, promoting heat radiation to outer space and achieving an average temperature drop of ∼5.62 °C. Attributed to the thermochromic mechanism, TC/BN composite aerogel can harvest visible light of 87 % in the solar spectrum to increase the material temperature by 28.3 °C, under an environment of −8.8 °C. Based on the EnergyPlus simulation, the employment of TC/BN composite aerogel contributes to decreasing the energy consumption of buildings in both hot and cold regions, including Cairo, Singapore, Alaska, Yakutsk, and so on. Besides, the peak values of heat release rate and total heat release during the combustion of TC/BN composite aerogels are significantly decreased by 70.6 % and 58.4 %, compared to those of TC composite aerogel. The produced protective char layer enhanced by BN nanosheets is capable of isolating the fire and suppressing the fire propagation, improving the fire safety of composite aerogels designed. The TC/BN composite aerogels provide a smart thermal regulation mode for radiative cooling and solar heating, overcome the problems from changing weather and environment, and significantly promote the practical application by enhanced fire safety. [ABSTRACT FROM AUTHOR]