The rapid development of electronic technology promotes the evolution of electronic devices towards integration, miniaturization and densification. The heat dissipation problem caused by over-heating accumulation and electromagnetic radiation will threat the reliability and life time of these devices, and even cause failure. Thus, it is desirable to prepare highly thermally conducive composites with electromagnetic shielding effect. Herein, the three-dimensional (3D) CNTs networks were grown in-situ on the foamed nickel by synergistic bimetallic catalysis to construct thermally conductive interconnected network, filling with epoxy resin (EP) to obtain the Fe-Ni@CNTs/EP composites. The foamed nickel not only works as the supported skeletons of the composites, but also accelerates the synthesis of CNTs networks via bimetallic catalysis of Fe and Ni. The resultant Fe-Ni@CNTs/ EP composites exhibit high in-plane and out-of-plane thermal conductivities of 0.83 and 1.23 W/(m center dot K), respectively. Moreover, the as-prepared Fe-Ni@CNTs/EP composites show the electromagnetic shielding efficiency of more than 37 dB in the X-band and a large alternating current (AC) conductivity of 2.2 & times; 10- 3 S/cm at 0-107 Hz. Besides, the average thermal expansion coefficient of Fe-Ni@CNTs/EP is 127.3 ppm/degrees C in the range of 20-190 degrees C, demonstrating excellent thermal stability. The work provides a new strategy for constructing efficient thermally conductive networks and has prospects in the fields of electronic, chip packaging and semiconductor devices.

ABSTRACT The present study prepared NBR/POM blends with varying rubber‐plastic ratios of 90/10, 80/20, 70/30 through a two‐stage blending approach involving internal/open‐mill blending and melt blending. The compatibilization performance of various compatibilizers polyether polyol (KGF‐400D), thermoplastic phenolic resin (PR‐12686E), thermosetting phenolic resin (SP‐1045), and epoxide resin (E51) was systematically evaluated at a fixed rubber/plastic ratio. Our findings demonstrated that all the investigated compatibilizers clearly improved the compatibility of the blends to varying degrees, among which SP‐1045 exhibited the most pronounced compatibilization effect. Both mechanical analysis and rubber process analysis (RPA) characterizations clearly indicated the mechanism of compatibility improvement. In the NBR/POM blend compatibilized with SP‐1045, the phenolic hydroxyl groups were found to in situ form hydrogen bonds with the ether oxygen in POM, enabling a considerable enhancement in compatibility with the POM phase. Meanwhile, the highly polar nitrile groups in NBR can interact strongly with the phenolic resin, further strengthening interfacial interactions. This work proposes an effective approach to enhance the compatibility of NBR/POM blends, which offers a promising strategy for developing high‐performance rubber‐plastic blends with tailored properties for demanding industrial applications.

High-performance polymer-based thermal management materials are urgently needed in high-power-density, extreme-environment, and special-function application scenarios. However, interfacial thermal resistance and disordered heat transfer pathways severely restrict the development and application of thermal conductive polymer composites. Herein, a synergistic covalent-noncovalent bonds interfacial architecture is constructed by in-situ growth of boron nitride nanotubes (BNNT) on boron nitride nanosheets (BNNS) and functionalization using ionic liquids, which significantly promotes interfacial heat transport in the resulting composite. Furthermore, the fillers are directionally aligned via a dual process combining vacuum-assisted self-assembly and ice-templating, establishing ordered heat transport pathways throughout the composite. The integrated low thermal resistance interfacial structure and long-range ordered heat transport network endows the composite with an in-plane thermal conductivity of 22.9 W m−1 K−1, along with exceptional tensile strength of nearly 80 MPa, volume resistivity of 1014 Ω cm, and a high limiting oxygen index (LOI) of 40%. The advantage of the covalent-noncovalent coupling strategy is also elucidated through non-equilibrium molecular dynamics (NEMD) simulations by comparing heat transport behavior in diverse interfacial structures. Device-level heat dissipation applications in operating desktop computer and smartphone further demonstrate the considerable potential of the composite as an outstanding multifunctional thermal management material.

Hexagonal boron nitride nanosheet (BNNS) is regarded as the most appealing thermally conductive filler for high-load electronic equipment because of its prominent thermal conductivity and outstanding electrical insulation. However, its application is hindered by lower-than-expected thermal conductivity when embedded in polymer matrices, primarily due to its intrinsic defects and poor interfacial interactions, leading to severe phonon scattering. In this work, we propose a synergistic thermal transport optimization strategy via the in-situ formation of a graphitic carbon nitride (g-C3N4) coating on BNNS. The g-C3N4 coating creates diversified phonon transport pathways to optimize thermal transmission within BNNS and enhances interfacial bonding between BNNS and polymer matrix. Coupled with the freeze-casting technique, a BNNS@CNx/EP composite containing only 14.4 wt% filler exhibits an out-of-plane thermal conductivity (κ⊥) of 1.48 W m−1 K−1, more than 1.5 times that of the BNNS/EP, which stems from the enhancement effect of g-C3N4 on phonon transport and the highly oriented filler skeleton. The enhancement effect of g-C3N4 on intrinsic thermal transmission and filler-matrix interaction of BNNS is further verified by theoretical calculation. This study provides a novel approach for improving both the intrinsic thermal conductivity of fillers and the interfacial thermal transport performance of composite materials, offering effective insights into the design and fabrication of advanced composites.

Polylactic acid (PLA) has been widely utilized in modern industries; however, during practical processing operations such as extrusion and injection molding, it consistently exhibits a sufficiently slow crystallization rate and low crystallinity. This study intends to investigate the influence of processing conditions on the solidification behavior of PLA during the injection molding process. The enthalpy transformation method (ETM) was employed to analyze the temperature decays throughout the entire injection process, with a focus on the effects of different cooling parameters on solidification kinetics. Four cooling conditions (denoted as Cases A-D) were compared, and the analysis results of these cases revealed that the melt cooling rate was heavily influenced by the mold temperature. The movement of the phase interface during melt solidification under various scenarios was also examined. Based on the experimental results, position-dependent characteristics of the phase transition plateau were identified. It was found that its width gradually increased from the wall to the sample centerline. This finding can be utilized in designing the cooling parameters for crystalline polymers during the injection operation. A comparative analysis was conducted between experimental cooling time and predicted cooling curves of PLA. Under varying cooling conditions, a generalized equation derived from fitting parameters using TPM (Three-Parameter Model) II was found to provide reasonably accurate estimates for injection-molded crystalline polymers, as supported by both experimental and calculated results. The present work offers valuable insights for designing cooling parameters for crystalline polymers in injection molding processes and provides a theoretical foundation for the future development of PLA composites.

The precise control over microphase-separated morphology especially the hydrophilic channels size within poly (aryl alkyl) (PAA) anion exchange membranes (AEMs) through rational molecular structure design is of great importance for efficient OH- conduction but remains a significant challenge. Here we report a design of multiblock AEMs PBF-b(t)-PBQ composed of superhydrophobic fluorinated segments and superhydrophilic dications pendant segments. By manipulating the length of both segments, we strategically controls the interconnectivity and width of hydrophilic channels, creating a smooth highway for ions conduction, and the consequent enhanced hydroxide conductivity up to 131.6 mS cm(-1) at 80 degrees C. In addition, the all-carbon backbones endow the membrane with endured alkaline stability with hydroxide conductivity retention of 84.8 % in 1 M KOH at 80 degrees C over 55 days. The assemble of membrane PBF-b(20h)-PBQ into an anion exchange membrane water electrolyser (AEMWE) delivers a current density of 1.02 A cm(-2) at 2.06 V, with sustained operation at 0.5 A cm(-2) for 98 h in 1 M KOH at 80 degrees C. Our work suggests the significance and a feasible strategy for controlling the size of hydrophilic channels within PAA membranes to develop high-performance AEMs.

The highly rigid structure of polyimide materials endows them with superior comprehensive properties. However, conventional polyimides typically suffer from challenges, such as insolubility and infusibility. Consequently, developing a polyimide that integrate high temperature resistance, mechanical strength, low dielectric constant, and recyclability is imperative. Addressing these, we introduced flexible siloxane unit into the polyimide backbone via copolymerization and engineered a dual-dynamic network comprising amide hydrogen bonds and aromatic disulfide bonds. This approach yielded a series of tunable silicone-containing soluble dynamic polyimides (Sol-Si-DDPIs) exhibiting a glass transition temperature (Tg) of up to 265.4 degrees C, 5 % thermal decomposition temperature (Td5%) exceeding 430 degrees C in nitrogen, and a low dielectric constant. Furthermore, the developed polyimide achieved thermal self-healing via hot-pressing and closed-loop recycling through solventassisted reprocessing while maintaining 98 % retention of tensile strength and elongation at break after one recycling cycle. The solvent-free hot-melt Sol-Si-DDPIs adhesive demonstrated excellent adhesion on diverse substrates, with a lap shear strength of 12.54 +/- 1.42 MPa. When compounded with graphene, the resulting thermal composite containing 7.5 wt% filler achieved a thermal conductivity of 3.32 +/- 0.02 W/(m.K) while retaining a high lap shear strength of 8.49 +/- 0.45 MPa. This thermal conductive adhesive combines good reprocessability and adhesion with the distinctive feature of containing recyclable fillers. Importantly, our material alleviates the thermal stability/glass transition temperature degradation caused by the introduction of flexible molecular chains and dynamic bonds into the polyimide structure. Thus, our work broadens the diversity and application scope of dynamic polyimides while offering pathways to achieving high performance, recyclability, and multifunctional integration in polyimide materials.

Graphene, endowed with ultra-high thermal conductivity, has always been the top candidate for developing high-performance heat management materials. The challenges in acquiring high-quality graphene and in tailoring of fabrication processes for graphene-based heat dissipation materials hinder their widespread application. Inspired by the coordination effects observed in biomaterials, multifunctional thermal management composites were fabricated from edge-oxidized graphene (EGO) via a coordination bond-facilitated layer-by-layer self-assembly process. Benefiting from the preserved essential structure of graphene due to selective oxidation and the oriented heat transport pathways driven by coordination bonds, Fe3+-coordinated EGO film (EGO-(Fe3+)2-F) boasted a metal-like in-plane thermal conductivity of 147.2 W m-1 K-1. DFT and MD simulations were employed to probe the role of coordination bonds-enabled interfacial electron transfer in optimizing the electron-phonon coupling mediated heat transfer in the EGO-(Fe3+)2-F. Leveraging the magnetic properties and the octahedral interfacial structure between EGO conferred by Fe3+-mediated coordination bonds, the EGO-(Fe3+)2-F achieved an EMI SE of over 80 dB in Ka-band, alongside a substantial tensile strength of 43 MPa. Excellent Joule heating and heat-stimuli responsiveness of EGO-(Fe3+)2-F validated the attainment of high-quality graphene. Our work offers a unique pathway to realize the application potential of graphene in the thermal management of electronic devices.

The escalating integration density of electronic devices has made efficient heat dissipation a critical challenge, highlighting the urgent need for high-performance thermal interface materials (TIMs). This work developed a novel hybrid filler by coating cobalt nanoparticles onto graphene nanosheets and subsequently grafting maleimide to form Co@MI-GNS. The functionalized filler is uniformly dispersed into a carboxylated cellulose nanofiber (CNF) matrix, and a series of Co@MI-GNS/CNF composite films were successfully fabricated using a layer-by-layer (LBL) self-assembly technique. During the LBL process, in-situ formation of "C-N-C" covalent bonds facilitated stable hydrogen bonding between the filler and the matrix, significantly enhancing the interfacial adhesion. Consequently, the LBL-assembled composites exhibited superior thermal conductivity (TC) as compared to the films made by conventional methods such as blade coating or template drying. The interfacial thermal resistance (ITR), calculated using the Foygel model, was remarkably as low as 9.41 & times; 10-10 m2 K W- 1, indicating a substantial improvement in thermal transfer efficiency. The positive influence of filler loading on TC enhancement is further validated by experimental data, a four-parameter fitting method (FPM) coupled with an enthalpy transformation method (ETM) simulation. The reliability of these theoretical predictions is confirmed by thermal dissipation tests on light-emitting diodes (LEDs) and computer CPUs. Collectively, our findings establish that LBL self-assembly is a promising approach for fabricating polymer-based TIMs that combine ultrahigh in-plane thermal conductivity with excellent mechanical flexibility, making them highly suitable for nextgeneration flexible electronic devices.

Reliable operation of high-frequency electronic devices is enhanced by high-performance thermal management materials. However, damage to thermally conductive composites caused by thermal stress and mechanical loading during operation significantly impairs their cooling efficiency for the devices. Herein, a nanocomposite integrating both thermal conduction and self-healing capabilities was achieved through the noncovalent bonding network formed between polyurethane (PU) and graphene (Gra) nanosheets. In the Gra orientation structure generated by the regulation of hot pressure, the pyrene ring on PU not only created pi-pi interaction with Gra but also cooperated with the pyrimidinone group to form pi-pi and quadruple hydrogen bonding interaction between polymer chains. The interfacial heat transfer and self-healing capabilities conferred by the noncovalent bonding network enable the nanocomposite to achieve in-plane thermal conductivity (lambda parallel to) of up to about 6.0 W m-1 K-1, with healing efficiencies of lambda parallel to exceeding 96% even after scratch repair and remodeling. Molecular dynamics simulations further confirmed the role of noncovalent bonds as the interfacial structure by analyzing the interfacial heat transfer behavior between PU and Gra. The construction of nanocomposites with integrated self-repairing and heat dissipation functionalities injects perspectives into the design of advanced multifunctional thermal management materials.

High-performance anion exchange membrane water electrolysers (AEMWEs) require highly conductive as well as mechanically and chemically robust anion exchange membranes (AEMs). However, the trade-off effect between hydroxide conductivity and water swelling remains a big challenge even for the state-of-the-art poly(aryl piperidinium) (PAP) AEMs of excellent alkali resistance, which is mainly caused by the ill-defined ion channels due to their intrinsic weak entropy-driven self-assembly. Here we innovatively report the poly(biphenyl acridineco-N,N-dimethylpiperidinium) (PBAMP) AEMs containing aromatic heterocyclic acridine. The it-it aggregation between acridine segments motivates the ordered assembly of polymer chains to construct interconnected hydrophilic channels for anions transportation. As a result, the optimized membrane, PBAMP-10 exhibits high hydroxide conductivity up to 155.4 mS cm-1 and acceptable water swelling ratio of 47.5% at 80 degrees C, good mechanical strength over 35 MPa in hydrated state, as well as excellent alkaline stability of only 2.9% attenuation in piperidinium cations after aging in 2 M NaOH at 80 degrees C for 600 h. Moreover, membrane PBAMP-10-based AEMWE achieves an outstanding current density of 1.98 A cm- 2 at 2.0 V at 80 degrees C. This work provides a feasible strategy concerning inter-chain it-it stacking for constructing interconnected ions transportation channels within PAP AEMs for AEMWEs.

Abstract Achieving a high β-phase content in poly(vinylidene fluoride) (PVDF) using low filler loadings remains a key challenge for flexible piezoelectric composites. Herein, a heterostructured MoS2/SnO2 nanofiller was designed to efficiently induce the nonpolar α-to-polar β-phase transition via interfacial charge transfer and built-in electric field effects. SnO2 nanoparticles were grown in situ onto the exfoliated MoS2 nanosheets to construct a 0D/2D heterojunction. At the interface, the work function difference drove charge transfer and interfacial polarization, which generated a strong built-in electric field, which synergistically promoted the alignment of PVDF’s-CF2-dipoles, in the presence of increased surface area and enhanced local stress transfer, thereby efficiently inducing the β-phase crystallization. PVDF/MoS2–SnO2 composite films containing 1.0 wt % heterostructured nanofiller were prepared by solution casting, and an optimal composite of PVDF/MoS2@SnO2 exhibited an ultrahigh β-phase content of 80.2% (in comparison to a typical 10% for neat PVDF) as well as a fracture elongation above 15% (demonstrating its good flexibility). Under periodic pressure, it showed significantly enhanced electrical output: an open-circuit voltage of 5.92 V and a short-circuit current of 365.70 nA, which were averagely three times those of neat PVDF. The present work confirmed the efficacy of the MoS2/SnO2 heterostructure, which could provide a filler design strategy for high-performance, flexible piezoelectric composite films, highlighting their potential in sensing and energy harvesting.

Water-based polyurethane with robust mechanical performance and excellent self-healing ability holds great promise for flexible functional devices. Herein, we proposed a strategy for preparing mechanically robust and self-healing waterborne polyurethane based on the regulation of a rigid-flexible hybrid soft segment with Diels-Alder bonds acting as healing motifs. By tuning the ratio of rigid polycarbonate to flexible polyether polyol, the resultant polyurethane exhibited a tensile strength ranging from 4.4 to 57 MPa and an elongation at break ranging from 669% to 1344%. The coexistence of hierarchical hydrogen bonding, π–π stacking interactions and Diels-Alder bonds plays a pivotal role in conferring enhanced mechanical robustness and dynamic properties on the material. Moreover, graphene nanoplatelets as a functional filler were incorporated into the waterborne polyurethane to fabricate photothermal self-healing and thermally conductive composites. These composites display a high thermal conductivity of 3.21 W m⁻¹ K⁻¹ and excellent photothermal self-healing capability upon heating or near-infrared (NIR) irradiation. This work not only provides a universal and facile approach to preparing waterborne polyurethane with integrated robust mechanical properties, high self-healing capability, and reprocessability, but also holds great potential for applications in the heat dissipation of advanced electronic devices.

The solar-driven evaporation of water is deemed as the most promising technology for producing freshwater. However, the complex recalcitrant organic pollutants will contaminate and even shorten the life time of the photothermal materials. Herein, the vertically aligned Fe-doping carbon nanosheets (Fe/CNSs) aerogel were constructed to produce fresh-water from sewage. The porous vertically oriented structure was built by using melem as carbon resource via the ice-templating method. The carbon nanosheets were grown in-situ on the vertically aligned skeletons of melem under the catalysis of ferrocene. The obtained Fe/CNSs composites exhibit excellent hydrophilicity and sunlight absorption as high as 97.3%, resulting in an outstanding solar evaporation efficiency of 91.7% and completely degradation of organic pollutants (methylene blue, methyl orange, tetracycline hydrochloride and bisphenol A) under 1 sun irradiation (1 kW m-2) synergistically. The Fe atoms doped in the carbon nanosheets, which accelerate the generation and transportation of radicals via the photo-Fenton, leading to a rapid degradation efficiency and address the issue of Fe recycling. This work provides a promising strategy for treating the wastewater containing refractory pollutants, such as industrial, dyeing and pharmaceutical wastewaters.

ABSTRACT Order‐aligned structures of thermally conductive fillers in the matrix are of great importance for the highly effective thermal interface materials (TIMs) in the fields of electronic devices, semiconductors, and electronic packaging. However, achieving high thermal conductivity via constructing ordered structures with low filler content remains challenging. Here, we construct vertically aligned Silicon nitride (Si 3 N 4 ) whiskers covered by the in situ growth of carbon nanotubes (CNTs) to form an efficient thermal conductive network. Owing to the successful construction of interconnected structures via thermally conductive Si 3 N 4 whiskers and CNTs, the Si 3 N 4 @CNTs/EP composite with filler content of 8.31 vol% exhibits high out‐of‐plane thermal conductivity of 1.54 W m −1 K −1 and excellent electrical insulation. This finding provides a promising strategy to design high‐performance thermal conductive composites for TIMs in high‐power devices.

Although the solar interfacial evaporation technology with the advantages of outstanding photothermal conversion, easy availability and high freshwater production, their photothermal materials still face the problem of contaminated by the organic pollutants in the raw waters such as sewage and natural water. Herein, we present a vertically oriented hierarchical C/TiO2 nanotubes with bifunction of photocatalytic degradation of pollutants and freshwater production via photothermal effect synchronously. The carbon nanoparticles of the hierarchical C/TiO2 nanotubes not only broaden the range of sunlight absorption to accelerate the water evaporation, but also reduced the recombination of electron-hole significantly to improve the photocatalytic efficiency. Meanwhile, the excellent water transportation via unique arranged arrays vertically, the abundant active sites derived from hierarchical structure, the vertical oriented C/TiO2 nanotubes exhibit a large solar-driven water evaporation rate of 1.59 kg m- 2 h- 1 and the methyl orange (MO) photodegradation efficiency of 92.9 % for the underneath sewage under 1 sun illumination synchronously. These findings have great potential applications in solarpowered production freshwater from wastewater and natural waters such as rain and river water.

Combined treatment is a promising strategy in antibacterial treatment, which could alleviate the shortcomings of monotherapy and achieve better therapeutic effects. In this work, mutual boost between free radical generation and photothermal effect for synergistic photothermal/thermodynamic antibacterial therapy was reported. Mesoporous silica nanoparticles were used as drug carrier for loading dibenzoyl peroxide (BPO). The pores of mesoporous silica nanoparticles were blocked by GSH-responsive polyethylenimine (PEI) layer. 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was then adsorbed via electrostatic force to prepare the nanosystem. At the site of bacterial infection, the BPO was released and decomposed to aryl radicals. The aryl radicals oxidized ABTS to photothermal reagent of ABTS·+, which produced photothermal effect to enhance the antibacterial effect under 808 nm laser irradiation. Moreover, the photothermal effect accelerated the decomposition of BPO to boost the levels of free radicals as a return, further improved the antibacterial efficiency. The in vitro experiments indicated that the photothermal/thermodynamic therapeutic nanosystem have a synergistic antibacterial effect efficiency (˃95 %) for both E. coli and S. aureus, as well as biofilm disruption and inhibition. This mutual boost between free radical ion generation and photothermal effect provides a new and feasible strategy for the synergistic antibacterial therapy.

Water scarcity and pollution are the challenges most countries face around the world, especially the large amount of organic wastewater. Solar-driven evaporation is an environmentally friendly and high-performance technology of freshwater production. However, photothermal materials fail when the water includes complex recalcitrant pollutants such as tetracycline hydrochloride (HCL-TC) and bisphenol A (BPA). Here, Fe@carbon nanotube (Fe@CNT) arrays were prepared in situ by using acetonitrile as the carbon source and ferrocene as the catalyst, followed by further solar-driven water evaporation and photo-Fenton catalytic degradation of organic pollutants synergistically. Owing to the Fenton effect and excellent solar absorption, Fe@CNTs accelerate the separation of photogeneration electron-hole pairs to improve the degradation of organic pollution and production of freshwater. Therefore, the Fe@CNT layers show outstanding solar absorption and hydrophilicity, resulting in a high solar evaporation efficiency of 94%. Meanwhile, the degradation efficiencies of organic pollutants (methylene blue, HCL-TC, and BPA) are more than 99% due to the synergistic effect of photothermal and photo-Fenton-catalysis effects. This work provides a promising strategy for the treatment of organic wastewater in an environmentally friendly way.

Poly (aryl piperidinium) (PAP) polymers with robust alkaline stability are widely regarded as the new generation of anion exchange membranes (AEMs) for applications in anion exchange membrane water electrolysis (AEMWE). However, the trade-off interaction between hydroxide conductivity and dimensional stability remains a tricky challenge. Here we provide a novel strategy concerning incorporating a rigid branching node triptycene into the PAP polymer matrix, leading to the branched AEMs with continuous and high free fractional volume up to 27.1 %, allowing for absorbing plentiful water to construct interconnected hydrophilic channels within the rigid skeleton. The membrane delivers much higher water uptake (WU) of 472.1 %, superior hydroxide conductivity (sigma) of 142.7 mS cm-1, but significantly depressed swelling ratio (SR) of 63.0 % at 80 degrees C in comparison with the linear counterpart (WU = 384.3 %, SR = 75.4 %, sigma = 96.7 mS cm-1), alleviating the trade-off effect. In addition, the PAP matrix endows the membrane with satisfactory alkaline stability in 1 M KOH over 960 h. When applied in AEMWE, we achieved a current density of 1.14 A cm-2 at 2 V, as well as the stable operation at a current density of 500 mA cm-2 at 60 degrees C over 105 h, and no detectable degradation of the membrane structure. The results highlight the extraordinary significance to manipulate the hydrophilic ions conduction channels and the substantial potential of these branched polymer materials for future applications in AEMWE.