Constructing controllable thermal conduction networks is the key to efficiently improve thermal conductivities of polymer composites. In this work, graphite oxide (GO) and functionalized carbon nanotubes (f-CNTs) are combined to prepare “Line-Plane”-like hetero-structured thermally conductive GO@f-CNTs fillers, which are then performed to construct controllable 3D GO@f-CNTs thermal conduction networks via self-sacrificing template method based on oxalic acid. Subsequently, thermally conductive GO@f-CNTs/polydimethylsiloxane (PDMS) composites are fabricated via casting method. When the size of oxalic acid is 0.24 mm and the volume fraction of GO@f-CNTs is 60 vol%, GO@f-CNTs/PDMS composites present the optimal thermal conductivity coefficient (λ, 4.00 W·m⁻¹·K⁻¹), about 20 times that of the λ of neat PDMS (0.20 W·m⁻¹·K⁻¹), also much higher than the λ (2.44 W·m⁻¹·K⁻¹) of GO/f-CNTs/PDMS composites with the same amount of randomly dispersed fillers. Meanwhile, the obtained GO@f-CNTs/PDMS composites have excellent thermal stability, whose λ deviation is only about 3% after 500 thermal cycles (20−200 °C).

Wood, a readily available and sustainable natural resource, has found widespread use in construction and furniture. However, its inherent flammability poses a potential fire risk. Although intumescent fire-retardant coatings effectively mitigate this risk, achieving high transparency in such coatings presents a significant challenge. In our approach, we employed a cross-linked network of phytic acid anion and N-[3-(trimethoxysilyl) propyl]-N,N,N-trimethylammonium cation to create a transparent "three-in-one" intumescent coating. The collaborative P/N/Si flame-retardant effect markedly improved the intumescent char-forming capability, preventing the wood from rapid decomposition. This resulted in a substantial reduction in heat release (13.9% decrease in THR) and an increased limiting oxygen index (LOI) value of 35.5%. Crucially, the high transparency of the coating ensured minimal impact on the wood's appearance, allowing the natural wood grains to remain clearly visible. This innovative approach provides a straightforward method for developing transparent intumescent flame-retardant coatings suitable for wooden substrates. The potential applications extend to preserving ancient buildings and heritage conservation efforts.

Effective thermal transport across solid-solid interfaces which is essential in thermal interface materials (TIMs), necessitates both optimal thixotropy and high thermal conductivity. The role of filler surface modification, a fundamental aspect of TIM fabrication, in the influence of these properties is not fully understood. This study employs the use of a silane coupling agent (SCA) to modify alumina, integrating experimental approaches with molecular dynamics simulations, to elucidate the interface effects on thixotropy and thermal conductivity in polydimethylsiloxane (PDMS)-based TIMs. Our findings reveal that the variations of SCAs modify both interface binding energy and transition layer thickness. The interface binding energy restricts macromolecular segmental relaxation near the interface, hindering desirable thixotropy and bond line thickness. On the contrary, the thickness of the transition layer at the interface positively influences thermal conductivity, facilitating the transport of phonons between the polymer and filler. Consequently, selecting an optimal SCA allows a balance between traditionally conflicting goals of high thermal conductivity and minimal bond line thickness, achieving an impressively low interface thermal resistance of just 2.45−4.29 K·mm²·W⁻¹ at 275.8 kPa.

Holographic optical elements (HOEs) based on polymer composites have become a research hot spot in recent years for augmented reality (AR) due to the significant improvement of optical performance, dynamic range, ease of processing and high yield rate. Nevertheless, it remains a formidable challenge to obtain a large field of view (FOV) and brightness due to the limited refractive index modulation. Herein, we report an effective method to tackle the challenge by doping an epoxy liquid crystal termed E6M, which enables a large refractive index modulation of 0.050 @ 633 nm and low haze of 5.0% at a doping concentration of 5 wt%. This achievement may be ascribed to the improved molecular ordering of liquid crystals within the holographic polymer composites. The high refractive index modulation can endow transmission-type holographic polymer composites with a high diffraction efficiency of 96.2% at a small thickness of 5 μm, which would promise the design of thin and lightweight AR devices.

Aerogels are widely used as thermal insulation materials because of their high porosity and low bulk density. However, the insulation performance of aerogels is limited to a narrow temperature range. Besides, the preparation of aerogel materials with precisely controlled and complex architectures is still challenging. Here, we report 3D printed polyimide/silica aerogel particle (PI/SAP) composite aerogels for thermal insulation in a wide range of temperature with customized applications. The printability and shape fidelity of 3D printed composite aerogels is improved by adding hydrophilic SAP as a rheology modifier. The resulting PI/SAP composite aerogel exhibits excellent flame-retardant properties and thermal insulation from −50 °C to 1300 °C. Moreover, the PI/SAP composite aerogel with customized shape can be applied for battery insulation at subzero temperatures, promising to be used as customizable and stable insulating materials in a variety of complex and extreme applications.

A variety of electromagnetic wave absorption materials (EMWAs) have been reported, but the integration of powder materials and multifunctional devices should be investigated in-depth to adapt to practical demands. Herein, carbon-coated cobalt composites were prepared by adsorbing magnetic metal cations into an anionic crystalline framework through an electrostatic encapsulate process. Excellent reflection loss (RL_min) of −40.49 dB and effective absorption bandwidth (EAB) of 5.36 GHz (RL<−10 dB, 10.4−15.76 GHz) was achieved with an optimal radar cross section (RCS) reduction of 34.9 dB·m² for the sample tested. For commercial applications, Co@CN-4 was integrated into sodium carboxymethyl cellulose (CMC) aerogel to create an ultra-lightweight composite aerogel that is compressive resistant and heat-holding while also having photothermal conversion capabilities.The hydrophobic modification makes it more widely useful. This study provides a new strategy for EWAMs to integrate versatility and improve their application prospects.

Currently, the enhancement in electromagnetic interference (EMI) performance of polymeric composite generally relies on either improving electrical conductivity (σ) for stronger electromagnetic (EM) reflections or tailoring structure for higher EM resonances. Herein, we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration (CPP-SS), which can reinforce these two factors simultaneously. The structural information was supplied by optical microscopy (OM) and scanning electron microscopy (SEM), both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene (UHMWPE)/graphene composites. Then, the result showed that CPP-SS can significantly improve the σ of samples. Ultimately, advanced specific EMI shielding efficiency of 31.1 dB/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%. Meanwhile, it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be surpassed. This work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPP-SS, and to bring us a simple and efficient approach for fabricating high-performance, strong and light-weight polymeric EMI shields.

Efforts to develop innovative water harvesting strategies offer powerful solutions to alleviate the water crisis, especially in remote and arid areas. Inspired by the hydrophobic/hydrophilic pattern of desert beetles and water self-propulsion property of spider silks, a double-strand hydrophobic PVDF-HFP/hydrophilic PAN nanofibers yarn is proposed by electrospinning and twisting techniques. The double-strand cooperation approach allows for water deposition on hydrophobic PVDF-HFP segment and transport under the asymmetric capillary driving force of hydrophilic PAN segment, thus speeded up the aggregation and growth of droplets. The effects of the composition and the diameter ratio of the two primary yarns were studied and optimized for boosting fog collection performance. The double-strand anisotropic yarn not only provide an effective method for water harvesting, but also hold the potential to inspire innovative design concepts for fog collection materials in challenging environments.

Passive daytime radiative cooling (PDRC) is an innovative and sustainable cooling technology that holds immense potential for addressing the energy crisis. Despite the numerous reports on radiative coolers, the design of a straightforward, efficient, and readily producible system remains a challenge. Herein, we present the development of a hierarchical aligned porous poly(vinylidene fluoride) (HAP-PVDF) film through a freeze-thaw-promoted nonsolvent-induced phase separation strategy. This film features oriented microporous arrays in conjunction with random nanopores, enabling efficient radiative cooling performance under direct sunlight conditions. The incorporation of both micro- and nano-pores in the HAP-PVDF film results in a remarkable solar reflectance of 97% and a sufficiently high infrared thermal emissivity of 96%, facilitating sub-environmental cooling at 18.3 °C on sunny days and 13.1 °C on cloudy days. Additionally, the HAP-PVDF film also exhibits exceptional flexibility and hydrophobicity. Theoretical calculations further confirm a radiative cooling power of 94.8 W·m⁻² under a solar intensity of 1000 W·m⁻², demonstrating a performance comparable to the majority of reported radiative coolers.

Significant progress has been made in wet adhesives for low salinity water, but exploration of general ionic adhesives for natural seawater is less developed because the high salinity could weaken interfacial bonding and shields electrostatic interactions, resulting in adhesion failure. Thus, the design of adhesives for natural seawater represents challenges less resolved. Herein, a cationic polyelectrolyte (PECHIA) containing imidazolacetonitrile unit was explored to prepare adhesives enabled by natural seawater. By combining the ion shielding effect with the “cation-dipole” interactions between PECHIA chains, aqueous solution of the PECHIA underwent coacervation and self-crosslinking in natural seawater, allowing for underwater adhesion to various substrates in seawater. The instantaneous lap-shear and tensile adhesion strengths are 47 and 119 kPa, respectively, while the cured adhesive shows ~739 kPa tensile adhesion in natural seawater. The design of PECHIA enables wet adhesives viable for applications in the diversified scenarios of natural seawater.

The preparation of high-performance thermal conductive composites containing liquid metals (LM) has attracted significant attention. However, the stable dispersion of LM within polymer solution and effective property contribution of liquid metals remains significant challenges that need to be overcome. Inspired by the properties of the dendritic structure of the tree root system in grasping the soil, “shear-induced precipitation-interfacial reset-reprotonation” processing strategy is proposed to prepare nanocomposites based on aramid micron fibers (AMFs) with hierarchical dendritic structure. Thanks to the combination of van der Waals force provided by hierarchical dendritic structure, electrostatic interaction between AMFs and LM, coordinative bonding of ―NH to LM, together with interfacial re-setting and multi-step protonation, several features can be achieved through such strategy: conducive to the local filler network construction, improvement of interfacial interaction, improvement of the stability of filler dispersion in the solvent, and enhancement of mechanical and thermal properties of the films. The resulting AMFs-pH=4/LM films demonstrate a thermal conductivity of 10.98 W·m⁻¹·K⁻¹ at 70% filler content, improvement of 126.8% compared to ANFs/LM film; while maintaining a strength of ~85.88 MPa, improvement of 77% compared to AMFs/LM film. They also possess insulation properties, enable heat dissipation for high power electronics. This work provides an effective strategy for the preparation of high performance polymer composites containing liquid metal.

With the rapid development of high-power-density electronic devices, interface thermal resistance has become a critical barrier for effective heat management in high-performance electronic products. Therefore, there is an urgent demand for advanced thermal interface materials (TIMs) with high cross-plane thermal conductivity and excellent compressibility to withstand increasingly complex operating conditions. To achieve this aim, a promising strategy involves vertically arranging highly thermoconductive graphene on polymers. However, with the currently available methods, achieving a balance between low interfacial thermal resistance, bidirectional high thermal conductivity, and large-scale production is challenging. Herein, we prepared a graphene framework with continuous filler structures in in-plane and cross-plane directions by bonding corrugated graphene to planar graphene paper. The interface interaction between the graphene paper framework and polymer matrix was enhanced via surface functionalization to reduce the interface thermal resistance. The resulting three-dimensional thermal framework endows the polymer composite material with a cross-plane thermal conductivity of 14.4 W·m⁻¹·K⁻¹ and in-plane thermal conductivity of 130 W·m⁻¹·K⁻¹ when the thermal filler loading is 10.1 wt%, with a thermal conductivity enhancement per 1 wt% filler loading of 831%, outperforming various graphene structures as fillers. Given its high thermal conductivity, low contact thermal resistance, and low compressive modulus, the developed highly thermoconductive composite material demonstrates superior performance in TIM testing compared with TFLEX-700, an advanced commercial TIM, effectively solving the interfacial heat transfer issues in electronic systems. This novel filler structure framework also provides a solution for achieving a balance between efficient thermal management and ease of processing.