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Highlights: m-BN/PNF nanocomposite paper with nacre-mimetic layered structures prepared via sol–gel film transformation approach presents excellent thermal conductivity, incredible electrical insulation, outstanding mechanical property and thermal stability. When the mass fraction of m-BN is 50 wt%, m-BN/PNF nanocomposite paper exhibits excellent thermal conductivity and electrical insulation. The λ∥ and λ⊥ are 9.68 and 0.84 W m−1 K−1, and the volume resistivity and breakdown strength are as high as 2.3 × 1015 Ω cm and 324.2 kV mm−1, respectively. The m-BN/PNF nanocomposite paper with 50 wt% m-BN also presents outstanding mechanical properties (tensile strength of 193.6 MPa) and thermal stability (thermal decomposition temperature of 640 °C). With the rapid development of 5G information technology, thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming prominent. In this work, "high-temperature solid-phase & diazonium salt decomposition" method is carried out to prepare benzidine-functionalized boron nitride (m-BN). Subsequently, m-BN/poly(p-phenylene benzobisoxazole) nanofiber (PNF) nanocomposite paper with nacre-mimetic layered structures is prepared via sol–gel film transformation approach. The obtained m-BN/PNF nanocomposite paper with 50 wt% m-BN presents excellent thermal conductivity, incredible electrical insulation, outstanding mechanical properties and thermal stability, due to the construction of extensive hydrogen bonds and π–π interactions between m-BN and PNF, and stable nacre-mimetic layered structures. Its λ∥ and λ⊥ are 9.68 and 0.84 W m−1 K−1, and the volume resistivity and breakdown strength are as high as 2.3 × 1015 Ω cm and 324.2 kV mm−1, respectively. Besides, it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640 °C, showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment. [ABSTRACT FROM AUTHOR]

In this work, stacked SiC fibers paper‐reinforced SiC ceramic matrix composites (SiCnf/SiC CMCs) were prepared by nanoimpregnation and transient eutectic (NITE) process using ultra‐long single‐crystal SiC nanofibers. The effect of the SiCnf surface modification via boron nitride (BN) interphase deposition as well as the sintering additive (Al2O3–Y2O3) content on the density, microstructure, and mechanical properties of SiCnf/SiC CMCs has been investigated systematically. The results revealed that the laminated SiCnf/SiC CMCs feature a significant saw‐tooth‐like curve on the load–displacement test, which indicates that the obtained laminated structure with the weak interlayer binding owning to the BN coating treatment possesses significant toughening to the SiC ceramics. Specifically, the SiCnf/SiC CMCs with the sintering additive content of 12 wt% revealed a fracture toughness of over 10 MPa m1/2 after 60 min of BN interface deposition, which is 104.31% higher than that of the composites prepared without BN coating. [ABSTRACT FROM AUTHOR]

Packaging insulation materials with high thermal conductivity and excellent dielectric properties are favorable to meet the high demand and rapid development of third generation power semiconductors. In this study, we propose to improve the thermal conductivity of epoxy resin (EP) by incorporating a three-dimensional boron nitride thermally conductive network. Detailedly, polyurethane foam (PU) was used as a supporter, and boron nitride nanosheets (BNNSs) were loaded onto the PU supporter through chemical bonding (BNNS@PU). After immersing BNNS@PU into the EP resin, EP-based thermally conductive composites were prepared by vacuum-assisted impregnation. Fourier transform infrared spectrometer and scanning electron microscope were used to characterize the chemical bonding and morphological structure of BNNS@PU, respectively. The content of BNNS in BNNS@PU/EP composites was quantitatively analyzed by TGA. The results show that the thermal conductivity of the BNNS@PU/EP composites reaches 0.521 W/m K with an enhancement rate η of 30.89 at an ultra-low BNNS filler content (5.93 wt. %). Additionally, the BNNS@PU/EP composites have excellent dielectric properties with the frequency range from 101 to 106 Hz. This paper provides an interesting idea for developing high thermal conductivity insulating materials used for power semiconductor packaging. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal CrystEngComm. It highlights the articles and papers featured in the current issue, including topics such as cobalt coordination polymers, environmental science, polymorphism, and lithium storage. The journal aims to advance the understanding and design of solid-state and crystalline materials. The Royal Society of Chemistry, a leading chemistry community, publishes the journal and reinvests its profits back into the chemistry community. [Extracted from the article]

Two-dimensional magnetic materials have been increasingly studied and discussed in the field of spintronics due to their unique electronic properties, high spin polarizability, and a variety of magnetic properties. In this paper, we report a new two-dimensional bilayer hexagonal monolayer material bilayer hexagonal structure (BHS)-CrN2 by first-principles calculations. The BHS-CrN2 nanosheet is an intrinsic ferromagnetic semiconductor material, and the Curie temperature obtained by Monte Carlo simulation is 343 K. The absence of a significant imaginary frequency in the phonon spectrum indicates the dynamic stability of BHS-CrN2. After ab initio molecular dynamics simulation, the supercell of BHS-CrN2 remains a complete structure, indicating its thermal stability. The calculated elastic moduli satisfy the Born–Huang criterion, indicating that the BHS-CrN2 system has good mechanical stability. Interestingly, the compressive strain and O atom doping can transform the electronic structure of BHS-CrN2 from a semiconductor to a half-metal, and the Curie temperature of BHS-CrN2 can be further increased to 1059 K when a 5% tensile strain is applied. Furthermore, the BHS-CrN2 in the ferromagnetic state shows a significant in-plane magnetic anisotropy energy of 0.01 meV per Cr, and the CrP2 and CrAs2 show a large out-of-plane magnetic anisotropy energy of 0.207 and 0.988 meV per Cr, respectively. The results show that the intrinsic ferromagnetic semiconductor BHS-CrN2 has good stability, high Curie temperature, and tunable magnetic properties, which is a promising material for room-temperature spintronic devices. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR)--based biosensors compete and excel among optical biosensors because of exceptional features such as high sensitivity, label-free, and real-time measurement, allowing the observation of molecular binding kinetics. In SPR biosensors and other biosensor techniques, surface functionalization and bioreceptor attachment are effective strategies to improve sensor performance. The application of an appropriate immobilization matrix for the bioreceptor is an essential step in maximizing the absorption of the bioreceptor on the sensor surface, thereby improving a specific target-sensor interaction. Furthermore, the materials should provide excellent optical properties to enhance the response signal. The high surface-to-volume ratio and high optical absorption of 2D materials qualify these requirements, thus promising advancements for SPR biosensors. This article reviews the recent SPR biosensor study with the use of the 2D materials family to improve the sensor performance, including graphene, transition metal dichalcogenides (TMDCs), MXene, black phosphorus (BP), perovskite, and boron nitride (BN). The materials properties and enhancement mechanisms of different 2D materials are discussed comprehensively. This review was expected to provide a future perspective and design approach for 2D materials-based SPR biosensors. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride is rapidly gaining interest as a platform for photonic quantum technologies, due to its two-dimensional nature and its ability to host defects deep within its large band gap that may act as room-temperature single-photon emitters. In this review paper we provide an overview of (1) the structure, properties, growth and transfer of hexagonal boron nitride; (2) the creationof colour centres in hexagonal boron nitride and assignment of defects by comparison with ab initio calculations for applications in photonic quantum technologies; and (3) heterostructure devices for the electrical tuning and charge control of colour centres that form the basis for photonic quantum technology devices. The aim of this review is to provide readers a summary of progress in both defect engineering and device fabrication in hexagonal boron nitride based photonic quantum technologies. [ABSTRACT FROM AUTHOR]

Phase-pure crystalline cubic boron nitride (c-BN) thin films are of immense scientific and technical interest because of their suitable properties for optoelectronic and high-power applications, high thermal conductivity and hardness, chemical inertness to ferrous materials in high-temperature and caustic environments, and high optical transmittance over a broad wavelength range from the ultraviolet (UV) to the visible spectrum. However, the lack of controlled fabrication techniques for high-quality c-BN films significantly affects the reliable practical applications of this material. Recently, phase-pure single-crystal c-BN and a new phase of BN with unique properties, called quenched-BN (Q-BN), have been synthesized using a pulsed laser annealing (PLA) technique to overcome the current impediments in c-BN synthesis. This review paper comprehensively examines the current status of analytical research on the growth, characterization, and properties (optical and electrical) of c-BN films fabricated by different synthesis techniques, with a particular emphasis on the immensely promising PLA technique. In particular, the paper focuses on the processes used to obtain phase-pure c-BN films via epitaxial growth, characterization of defects and interfaces, and control of the structural, electrical, and optical properties of these films by controlling the growth parameters, including the laser–solid interaction for the direct conversion of nanocrystalline hexagonal boron nitride (h-BN) into crystalline c-BN using the PLA technique. The latest developments in c-BN electronics are also discussed, with a focus on producing p-and n-type conductivity using different dopants to achieve dopant concentrations far beyond the retrograde thermodynamic solid solubility limits. Finally, the future prospects and possible applications in emerging areas are discussed, as well as the goals and guidelines for future research of PLA-grown c-BN films. A comprehensive overview of the properties, application, characterization, shortcomings, and future prospects of c-BN [ABSTRACT FROM AUTHOR]

In this paper, a dual-layer plasmonic material-based electro-absorption modulator (EAM) is designed and investigated. Indium-tin-oxide (ITO), along with dielectric materials such as boron nitride (hBN) and hafnium dioxide (HfO2), is integrated into the Si waveguide for tuning the light propagating inside the device. The device showed enhanced performance in terms of extinction ratio (ER) = 34.48 dB/µm, the figure of merit (FOM) = 493, and insertion loss (IL) = 0.06 dB/µm for On-state at 1.55 µm wavelength. Also, the dual-state behavior of the EAM was observed and investigated. An IL of 22.22 dB/µm and 25.39 dB/µm was observed for the Off-On and On-Off configurations, respectively. A modulation frequency (${f_{3dB}}$ f 3 dB ) of 1.72 THz and 340 GHz was achieved for the EAM with hBN and HfO2 as the dielectric material. The investigated EAM with different dielectric materials has the potential to be integrated into future-generation photonic integrated circuits (PICs). [ABSTRACT FROM AUTHOR]

From quantum communications to quantum computing, single-photon emitters (SPEs) are essential components of numerous quantum technologies. Two-dimensional (2D) materials have especially been found to be highly attractive for the research into nanoscale light–matter interactions. In particular, localized photonic states at their surfaces have attracted great attention due to their enormous potential applications in quantum optics. Recently, SPEs have been achieved in various 2D materials, while the challenges still remain. This paper reviews the recent research progress on these SPEs based on various 2D materials, such as transition metal dichalcogenides (TMDs), hexagonal boron nitride (hBN), and twisted-angle 2D materials. Additionally, we summarized the strategies to create, position, enhance, and tune the emission wavelength of these emitters by introducing external fields into these 2D system. For example, pronounced enhancement of the SPEs' properties can be achieved by coupling with external fields, such as the plasmonic field, and by locating in optical microcavities. Finally, this paper also discusses current challenges and offers perspectives that could further stimulate scientific research in this field. These emitters, due to their unique physical properties and integration potential, are highly appealing for applications in quantum information and communication, as well as other physical and technological fields. [ABSTRACT FROM AUTHOR]

Electronic devices play an increasingly vital role in modern society, and heat accumulation is a major concern during device development, which causes strong market demand for thermal conductivity materials and components. In this paper, a novel thermal conductive material consisting of polydimethylsiloxane (PDMS) and a binary filler system of h-BN platelets and Al2O3 nanoparticles was successfully fabricated using direct ink writing (DIW) 3D printing technology. The addictive manufacturing process not only endows the DIW-printed composites with various geometries but also promotes the construction of a 3D structural thermal conductive network through the shearing force during the printing process. Moreover, the integrity of the thermal conductive network can be optimized by filling the gaps between the BN platelets with Al2O3 particles. Resultingly, the configuration of the binary fillers is arranged by the shearing force during the DIW process, fabricating the thermal conductive network of oriented fillers. The DIW-printed BN/Al2O3/PDMS with 45 wt% thermal conductive binary filler can reach a thermal conductivity of 0.98 W/(m·K), higher than the 0.62 W/(m·K) of the control sample. In this study, a novel strategy for the thermal conductive performance improvement of composites based on DIW technology is successfully verified, paving a new way for thermal management. [ABSTRACT FROM AUTHOR]

Complementary electronics has represented the corner stone of the digital era, and silicon technology has enabled this accomplishment. At the dawn of the flexible and wearable electronics age, the seek for new materials enabling the integration of complementary metal-oxide semiconductor (CMOS) technology on flexible substrates, finds in low-dimensional materials (either 1D or 2D) extraordinary candidates. Here, we show that the main building blocks for digital electronics can be obtained by exploiting 2D materials like molybdenum disulfide, hexagonal boron nitride and 1D materials such as carbon nanotubes through the inkjet-printing technique. In particular, we show that the proposed approach enables the fabrication of logic gates and a basic sequential network on a flexible substrate such as paper, with a performance already comparable with mainstream organic technology. [ABSTRACT FROM AUTHOR]

Wide‐bandgap, layered hexagonal boron nitride (h‐BN) possesses excellent electrical insulation and ultrahigh thermal conductivity simultaneously, offering a perfect candidate for the growing demands of heating dissipations in modern chip industries and power electronics. Hybrids of h‐BN with polymers fulfill the thermal management materials (TMMs) requirement of flexibility, while the composite poses severe challenges in the interfacial bonding and excess thermal resistance. To date, the practical bonding between h‐BN intrinsic surfaces and polymer matrices remains elusive. This work reports on the effective alignment of h‐BN micro‐lamellae by introducing nitrogen‐atoms‐containing polymers as inter‐lamellae bridging mediums. Based on theoretical calculations the hydrogen bonding between polymer chains and the BN surface is revealed by differential charge densities mapping. It is shown experimentally that the neuron‐like polymer bundles strongly bonding surfaces of two neighboring h‐BN platelets as direct, microscopic evidence of the structure models. An extra alignment of h‐BN induced by this strong interfacial interaction leads to a higher degree of h‐BN stacking order, boosting the thermal conduction by eight times. These results reveal one unprecedented method to non‐covalently functionalize the h‐BN surface and expand the TMMs family in the dimension of the filler size, paving the way for exploring the larger‐sized ceramic TMMs. [ABSTRACT FROM AUTHOR]

In the first part of this paper, we present a model that explains and determines quantitatively the twists between nucleation islands in the case of a Volmer–Weber heteroepitaxial growth of tetrahedrally coordinated semiconductors along hexagonal orientations. These twists are caused by the network of the screw components of the 60° misfit dislocations. The orientations of the screw components are distributed randomly, and the maximum twist is obtained when all the screw components have the same orientation. The maximum twists are related to the density of misfit dislocations and, therefore, increase with the mismatch between the deposited materials and their substrate. In the second part of the paper, we study five systems having a large distribution of mismatches from 4% to 19%. For the four systems fulfilling the conditions necessary for the application of the model (plastic relaxation of grown islands), the measured maximum twists fit with the calculated values, thereby validating the model. The twists of nucleation islands are related to the mismatch and are, therefore, intrinsic to the material systems. The defects created at the coalescence of twisted islands determine the initial microstructure/defect distribution of the nucleation layer. [ABSTRACT FROM AUTHOR]

Edge kinetics in 2D structures has been a key to understanding the growth. In this paper, the effect of hydrogen passivation on the growth of hexagonal boron nitride (h-BN) was studied. Without hydrogen, the filling process of the gap on bare edges of h-BN is difficult because of the formation of dimers that distorts the edge. With hydrogen passivation, such difficulty can be largely reduced. In addition, hydrogen passivation can reduce the edge bending to the substrate. In summary, the amount of hydrogen passivation during the growth is the long-ignored parameter and can be the key to a good crystal quality. [ABSTRACT FROM AUTHOR]

Discovery of graphene and its distinctive set of properties and application worthiness led to a massive increase in researcher's attention in two-dimensional layered materials. There are various two-dimensional layered materials like graphene, graphyne, borophene, germanene, silicene, hexagonal boron nitride, MXenes, and transition metal dichalcogenides. Transition metal dichalcogenides especially dichalcogenide of molybdenum are being recognized as an alternative to graphene, due to their exceptional properties and potential for use in various domains. Owing to high surface area and high aspect ratio, nanostructured materials and nanocomposites have been recognized as potential field emitters and supercapacitor electrode. Therefore, an attempt has been made to hydrothermally synthesize MoS2 nanoflowers on carbon paper and investigate their field emission and super-capacitive behavior. We have demonstrated that MoS2–carbon paper nanocomposite can be competitive with various other well-known field emitters. Further, we have established that a stable field emission current can be measured with a turn-on field as low as 0.94 V/μm and a field enhancement factor up to ~ 5373 at 1 mm cathode–anode separation. Owing to the low turn-on field and its morphology, MoS2–carbon paper nanocomposite could be explored for field emission-based displays, field emission lamps, and vacuum electronic components and devices. The highest specific capacitance of 137 F.g−1 was calculated for NaOH electrolyte and highest saturation potential is observed for Na2SO4 electrolyte. For NaOH, the area under the curve decreases with increasing electrolyte concentration, and the maximum area under the curve is observed in the case of 0.5 mol.cc−1 concentration. Along with field emission application, the experimental results also propose the multifunctional potential of MoS2–carbon paper nanocomposite in super-capacitors and energy storage. [ABSTRACT FROM AUTHOR]

With the development of integrated circuits and the miniaturization/ integration of electronic devices, heat dissipation solutions have become an increasingly important issue. The thermal conductivity of polymer-based thermal management materials is typically influenced by the amount of incorporated fillers. However, an innovative solution to increase the thermal conductivity without increasing the total filler content is the improvement of the filler connectivity by using specific surface modifications. Surface modifications using thermal conductive submicron particles can reduce the interfiller distances, acting as thermal bridges between the particles. In this paper, copper submicron particles modified BN (BN@CuSMPs) have been prepared by in situ reduction and mixed with graphene oxide (GO). A three-dimensional BN@CuSMPs/rGO aerogel (CBGA) framework with "point-surface" connection has been prepared by using the self-assembly mode of GO. CBGA/EP composites were then prepared using epoxy resin (EP) as matrix and a vacuum assisted impregnation method. The thermal conductivity of CBGA/EP composites has been found to be 1.918 W m−1 K−1 using a filler content of 19.61%, which was 12.8% higher than that of BN/rGO/EP composites and 909.5% higher than that of pure EP. The thermal resistance of the composites was analyzed using the Foygel model. It was found that the introduction of CuSMPs effectively decreased the thermal resistance between the BN particles, forming a thermal conductive three dimensional network inside the polymer-based material system. [ABSTRACT FROM AUTHOR]

Interest in fullerene-based polymer structures has renewed due to the development of synthesis technologies using thin C60 polymers. Fullerene networks are good semiconductors. In this paper, heterostructure complexes composed of C60 polymer networks on atomically thin dielectric substrates are modeled. Small tensile and compressive deformations make it possible to ensure appropriate placement of monolayer boron nitride with fullerene networks. The choice of a piezoelectric boron nitride substrate was dictated by interest in their applicability in mechanoelectric, photoelectronic, and electro-optical devices with the ability to control their properties. The results we obtained show that C60 polymer/h-BN heterostructures are stable compounds. The van der Waals interaction that arises between them affects their electronic and optical properties. [ABSTRACT FROM AUTHOR]

Traditional thermally conductive materials are gradually losing their advantages as the electronics industry develops rapidly. Polymers are in urgent need of a material with high thermal conductivity, stable structure, good mechanical properties and oxidation resistance, which makes hexagonal boron nitride (h-BN) an excellent heat transfer filler for polymer composites. Boron nitride nanosheets (BNNS) are monolayers of hexagonal boron nitride, and theoretical studies have shown that BNNS have a higher thermal conductivity than h-BN (up to 400Wm-1K-1, in-plane). This paper provides a comprehensive review of various methods for preparing BNNS, including mechanical exfoliation, liquid phase sonication exfoliation and chemical vapor deposition (CVD). In addition, various factors affecting the thermal conductivity of BNNS, including grain boundary, grain size and defects, are also discussed. Then, the influence of BNNS as filler on the thermal conductivity of the polymer was further discussed. Finally, this paper summarizes the existing BNNS applications and lists the application scenarios of BNNS in various fields. The purpose of this review is to summarize the previous work and put forward the prospect and future development direction of preparing high thermal conductivity BNNS-included polymer composites, so as to stimulate the research and improvement of new preparation methods for BNNS and promote its practical application as heat transfer materials. [ABSTRACT FROM AUTHOR]

This paper reports on thermal and electrical conduction properties of polypropylene (PP)-based nanocomposite used for high voltage direct current cable insulation. To improve the thermal conductivity of the PP/propylene-based elastomer (PBE) blend (noted as PB), boron nitride (BN) nanosheets with high thermal conductivity are added. The pretreatment process through template method is to obtain a three-dimensional (3D) network structure composed of BN nanosheets (noted as 3DBN). Then the 3DBN is added into the PP/ PBE blend, in which the 3D networks are locally arranged and the other BN nanosheets are randomly dispersed. Thermal conductivity is estimated, while electrical conductivity is measured under electric fields of 5–40 kV mm−1 at various temperatures. Carrier trap distribution is derived from isothermal surface potential decay method. In addition, the microstructure and crystallization characteristics of the nanocomposites are measured. The results show that the thermal conductivity of the PP/PBE blend is improved obviously by the addition of the locally arranged 3DBN, and that of PB-3DBN-10 is increased by 16% compared with that of PB. Deep traps are introduced by the dispersed BN nanosheets and the electrical conduction is reduced, which becomes increasingly evident with the filler content and temperature. It is suggested that the introduction of thermal conductive fillers with a 3D network structure and well-dispersed state can synergistically enhance the thermal conductivity and insulation performances of the PP-based material. [ABSTRACT FROM AUTHOR]

Support effect is an important issue in heterogeneous catalysis, while the explicit role of a catalytic support is often unclear for catalytic reactions. A systematic density functional theory computational study is reported in this paper to elucidate the effect of a model boron nitride (BN) support on the first N-H bond activation step of NH3 on Run (n = 1, 2, 3) metal clusters. Geometry optimizations and energy calculations were carried out using density functional theory (DFT) calculation for intermediates and transition states from the starting materials undergoing the N-H activation process. The primary findings are summarized as follows. The involvement of the model BN support does not significantly alter the equilibrium structure of intermediates and transition states in the most favorable pathway (MFP). Moreover, the involvement of BN support decreases the free energy of activation, ΔG≠, thus improving the reaction rate constant. This improvement is more obvious at high temperatures like 673 K than low temperatures like 298 K. The BN support effect leading to the ΔG≠ decrease is most significant for the single Ru atom case among all three cases studied. Finally, the involvement of the model BN may change the spin transition behavior of the reaction system during the N-H bond activation process. All these findings provide a deeper insight into the support effect on the N-H bond activation of NH3 for the supported Ru catalyst in particular and for supported transition metal catalysts in general. [ABSTRACT FROM AUTHOR]

This paper presents the development of an all-in-one probe to simultaneously measure all components of the generalized Ohm's law in reversed-field pinch plasmas and tokamaks. The polyhedral configuration of the Mach probe is achieved through the specific arrangement, angle, and depth of the collimator channel apertures drilled into the surface of a hollow boron nitride cylinder encasing it. This probe includes a central Mach probe to assess the ion velocity field in three dimensions. Initial tests at the RELAX and Madison Symmetric Torus machines have confirmed the probe's effectiveness, revealing an octahedron form similar to a tetrahedron. The probe seems to function correctly and is expected to facilitate the empirical validation of two-fluid equilibria at the periphery of toroidal plasmas. [ABSTRACT FROM AUTHOR]

Polymer-like dielectrics with superb thermal conductivity as well as high dielectric properties hold great promise for the modern electronic field. Nevertheless, integrating these properties into a single material simultaneously remains problematic due to their mutually limited physical connotations. In this study, we developed high-quality thermally conductive epoxy composites with excellent dielectric properties. This was achieved by incorporating surface-functionalized microscale hexagonal boron nitride (BN) along with N-[3-(Trimethoxysilyl)propyl]ethylene diamine (DN) and N-[3-(Trimethoxysilyl)propyl]aniline (PN). In the resulting epoxy composite, microscale BN serves as the primary building block for establishing the thermally conductive network, while silica particles act as bridges to regulate heat transfer and reduce interfacial phonon-scattering. The prepared composites were thoroughly examined across various filler contents (ranging from 10 to 80 wt%). Among them, the DNBN/epoxy composite exhibited higher thermal conductivity (in-plane: 47.03 W m−1 K−1) at 60 wt% filler content compared to BN/epoxy (39.40 W m−1 K−1) and PNBN/epoxy (33 W m−1 K−1) composites. These results highlight the usefulness of surface modification of BN in improving compatibility between fillers and epoxy, ultimately reducing composite viscosity. Furthermore, the DNBN/epoxy composite at 60 wt% demonstrated superb dielectric constant (∼6.15) without compromising on dissipation loss (∼0.06). The strategy adopted in this study offers significant insights into designing dielectric thermally conductive composites with superior performance outcomes. [ABSTRACT FROM AUTHOR]

Negative ion mode paper spray mass spectrometry (PS-MS) suffers from intense background noise and unstable MS signal. For the first time, we reported fluorinated boron nitride nanosheet (h-FBN) assisted negative ion PS-MS for the detection of a series of molecules. We demonstrated that the introduction of h-FBN can greatly improve the detection sensitivity and signal stability in the negative ion mode. [ABSTRACT FROM AUTHOR]

In this work, a novel thermal conductive and electrical insulation h‐BN@AgNPs/ANFs composite paper was fabricated by vacuum‐assisted filtration approach. Specifically, hexagonal boron nitride (h‐BN) was incorporated via polydopamine pretreatment and subsequent decoration by silver nanoparticles, which served as bridges to link neighboring h‐BN sheets. The results revealed that the thermal conductivity of as‐prepared composite paper increased to 1.032 W/m K with 40 wt% filler loading, about 464% higher than the pure ANFs paper, which was attributed to the efficient thermal conductive networks within the paper and strong interfacial combination through hydrogen bonding. Besides, the as‐prepared composite paper exhibited excellent mechanical property with the maximum tensile strength over 90 MPa, and good electrical insulation performance. More importantly, this work provided a promising strategy to achieve high thermal conductivity ANFs based composite paper by constructing efficient thermal conductive networks, which had potential to be used in the field of electronic packaging. [ABSTRACT FROM AUTHOR]

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Using the first-principles calculation, two doping two-dimensional (2D) BN (boron nitride) polymorphs are constructed in this work. The two doping 2D BN polymorphs B5N6Al and B5N6C sheets are thermally stable under 500 K. All the B6N6, B5N6Al, and B5N6C sheets are semiconductor materials with indirect band gaps on the basis of a hybrid functional. The anisotropic calculation results indicate that Young's modulus (E) and Poisson's ratio (v) of the B6N6, B5N6Al, and B5N6C sheets are anisotropic in the xy plane. In addition, the magnetic properties of the B6N6, B5N6Al, and B5N6C sheets have also been investigated. According to the calculation of the magnetic properties, B6N6 sheet does not exhibit magnetism, while it shows weak magnetism after doping carbon atom to the BN sheet. This paper explores the influence mechanism of doping different atoms on the basic physical properties of two-dimensional BN sheets. It not only constructs a relationship between structure and performance but also provides theoretical support for the performance regulation of BN materials. [ABSTRACT FROM AUTHOR]

The emerging field of flexible tactile sensing systems, equipped with multi-physical tactile sensing capabilities, holds vast potential across diverse domains such as medical monitoring, robotics, and human–computer interaction. In response to the prevailing challenges associated with the limited integration and sensitivity of flexible tactile sensors, this paper introduces a versatile tactile sensing system capable of concurrently monitoring temperature and pressure. The temperature sensor employs carbon nanotube/graphene conductive paste as its sensitive material, while the pressure sensor integrates an ionic gel containing boron nitride as its sensitive layer. Through the application of cost-effective screen printing technology, we have successfully manufactured a flexible dual-mode sensor with exceptional performance, featuring high sensitivity (804.27 kPa − 1 ), a broad response range (50 kPa), rapid response time (17 ms), and relaxation time (34 ms), alongside exceptional durability over 5000 cycles. Furthermore, the resistance temperature coefficient of the sensor within the temperature range of 12.5 °C to 93.7 °C is −0.17% °C−1. The designed flexible dual-mode tactile sensing system enables the real-time detection of pressure and temperature information, presenting an innovative approach to electronic skin with multi-physical tactile sensing capabilities. [ABSTRACT FROM AUTHOR]

In this study, h-BN-OH was obtained by hydroxylating h-BN and subsequently KH560 was grafted onto the surface of h-BN-OH, resulting in h-BN-KH560. The h-BN-KH560 was then dispersed in an epoxy resin (EP) to create an EP/h-BN-KH560 adhesive solution, with the content of h-BN-KH560 being varied. Graphene oxide (GO) was dispersed in PMIA precipitated fibers to produce PMIA/GO composite paper. Finally, the surface of the composite paper was evenly coated with the EP/h-BN-KH560 adhesive solution, and then PMIA/EP/GO/h-BN composites with different h-BN-KH560 contents and good thermal conductivity were prepared by hot pressing. The FTIR analysis confirmed the successful grafting of KH560 onto the surface of h-BN-OH. By utilizing h-BN-KH560 and GO as thermal conductive fillers, we achieved a higher thermal conductivity in the composite material, creating a "dual thermal conductivity network" compared to using a single filler. Additionally, the thermal conductivity increased as the content of h-BN-KH560 increased. At h-BN-KH560 contents of 20 wt%, 40 wt%, and 60 wt%, the thermal conductivities of the prepared PMIA/EP/GO/h-BN composites were 0.661 Wm−1K−1, 1.082 Wm−1K−1, and 1.206 Wm−1K−1, respectively. Importantly, the addition of the thermal conductive filler did not significantly affect the thermal stability of the composites. [ABSTRACT FROM AUTHOR]

Explosives can be divided into low and high, the efficient detection of which is of utmost importance for security reasons. A major component of high explosives is the nitroaromatic compounds. These explosives, when sealed, have difficulty detecting. In this review work, the major techniques for explosive detection i.e. animal olfaction, calorimetric sensors, immunosensors, ion mobility spectrometry, and Raman spectroscopy are discussed. The materials or compounds comprising nitroaromatic sensors have been a topic of major research for the last three decades. Nanomaterials do provide an acceptable solution for portable, affordable, and efficient detection of analytes of explosive nature due to their redox properties. 3D nanomaterials like TiO2, Au, SiO2, Ag and CdSe-ZnS, 0D materials like CdSe, CdTe, ZnS and MoS2 can detect nitroaromatic compounds efficiently. In the upcoming technology, the incorporation of quantum dots is also considered for explosive detection. As an option for prospective research in the field, development in the use of boron nitride for detecting explosives is also a good option. A comprehensive review of such materials is discussed in this review paper. [ABSTRACT FROM AUTHOR]

This paper presents an analysis based on experimental data for pointing out the behavior of rapeseed oil when it is additivated with a modifier of friction and wear, the nano hexagonal Boron nitride. All tests are done on a four-ball machine, in mild regime. Test parameters were sliding velocity (0.38 m/s, 0.53 m/s, 0.69 m/s, corresponding to the spindle rotational speed of the four-ball machine of 1000 rpm, 1400 rpm, 1800 rpm (±10 rpm),), force (100 N – 300 N), test duration 1 h. There were calculated the average friction coefficient during the test and the average wear scar diameter (WSD) for each test. The same test parameters were done twice and the values in this paper are the average of these two tests. Wear was discussed for the same velocity range, in terms of WSD, but for comparing tests with different sliding velocity (implicitly, different sliding distances), there was used the wear rate of the wear scar diameter. The results on wear parameters, using additivated rapeseed oil, do not show spectacular results for the parameters tested in this study, but underline the “insensitivity” of the lubricants to the variation of the test regime (especially with respect to sliding speed), which is desirable for certain applications. [ABSTRACT FROM AUTHOR]

Constructing interconnected thermally conductive networks in a polymer matrix is essential for efficient heat transport in thermally managed materials. Thermally conductive network structures typically have meager thermal resistance, and heat transfer into the material is rapidly exported along such networks. However, increasing the thermally conductive networks inside the polymer matrix is still challenging. This paper prepared high thermal conductivity composites with "primary‐secondary" thermal conductivity networks by combining two processes: constructing three‐dimensional thermally conductive skeletal networks and physically blending fillers, using epoxy resin as the matrix. The performance test results showed that the thermal conductivity of the composites reached 1.65 W/(m K) when the boron nitride (BN) content reached 33.5 wt%, which was 842.8% and 150% higher than that of pure epoxy (EP) and composites with randomly dispersed fillers. This highly efficient heat transfer behavior is mainly due to the synergistic effect of the two‐level thermally conductive network, which weakens the scattering effect of phonons to a great extent. Also, the dielectric properties of the composite material, especially the transport of carriers inside the material under strong electric fields, were discussed in this paper. This work provides ideas and methods for preparing electrical and electronic devices applied to high power density. [ABSTRACT FROM AUTHOR]

Organic transistors are crucial components in future flexible electronics due to their excellent properties and ease of circuit integration. Previously, we demonstrated that flexible organic (polyimide) thermal transistors could be prepared using commercial graphite paper as the substrate. These materials exhibited excellent temperature sensitivity, linearity and recoverability due to the intrinsically high thermal conductivity of graphite. In this study, boron nitride (BN) sheets/polyimide hybrid dielectric layers were synthesized for the fabrication of flexible organic transistors using a commercial graphite paper. Under test, the results showed that the introduction of BN sheets was beneficial in improving the mobility and transistor characteristics of the device, as well as enhancing the overall stability. The as-fabricated transistors virtually exhibited no hysteresis at all BN contents. Boron nitride (BN) sheets were added to the fluorinated polyimide (FPI) matrix to form hybrid dielectric layer for improving the performance of flexible organic transistors fabricated on commercial graphite paper. The results showed that the device with BN/FPI hybrid dielectric layer exhibited higher output current (Id) and stability. Besides, the devices remained hysteresis-free at all tested BN sheet contents. [ABSTRACT FROM AUTHOR]

Thermal decomposition of NH3BH3 and Li(BH3NH2BH2NH2BH3) was investigated at temperatures up to 1000 °C under various conditions with an inert atmosphere. It was found that complete dehydrogenation of ammonia borane towards amorphous boron nitride (a-BN) occurs at 850 °C when using monel reactors or at 1000 °C with the hot isostatic pressing method (HIP), which is significantly lower than was earlier reported. Li(BH3NH2BH2NH2BH3) was found to decompose towards hexagonal boron nitride (h-BN) at 1000 °C with the HIP method but at 850 °C in monel reactors towards a mixture of a-BN and h-BN. The findings are confirmed by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

In the present study, we report the synthesis, characterization and assessment of the carbon dioxide adsorption capacity of a composite made of boron nitride and carbon. The material is obtained through a two-step process. In the initial step, ammonia borane is introduced into the pores of a zeolitic imidazolate framework (ZIF-8) using a novel one-pot synthesis method. The ZIF-8 is formed in situ around the ammonia borane molecules, eliminating the need for an infiltration step. The successful confinement of ammonia borane within the ZIF-8 structure is verified through different characterization techniques (IR, XRD, TGA-DSC, and 11B MAS NMR). In the second step, ZIF-8 containing confined ammonia borane is pyrolyzed. Ammonia borane acts as a precursor of boron nitride and the process results in a composite comprising carbon, boron and nitrogen. The composite was subsequently characterized and evaluated as a potential adsorbent for carbon dioxide. With a specific surface area of 56 m2 g−1, the composite demonstrates a CO2 uptake of 1.94 mmol g−1 (or 85.4 mg g−1) when exposed to 1.5 bar of CO2 at 30 °C. This value surpasses reported capacities of other boron nitride-based materials as CO2 adsorbents. When comparing the CO2 adsorption capacity in terms of the specific surface area, a significant enhancement is observed (34 × 10−3 mmol m−2). This suggests that the material provides more active sites for CO2 adsorption, such as polarized B–C, B–N, and C–N bonds. This key factor may be even more important than having a large specific surface area. Therefore, the potential for developing new boron-based materials with enhanced CO2 adsorption capacities lies in increasing both specific surface area and active sites. [ABSTRACT FROM AUTHOR]

This paper presents a detailed analysis of the thermal conductivity behaviors exhibited by a diverse array of nanostructured materials, ranging from multilayer graphene nanocomposites to semiconductor-based nanostructures such as Bi0.5Sb1.5Te3 and In0.53Ga0.47As composites. The investigation extends to superlattices, nanowires, and hybrid nanostructures, encompassing materials like hexagonal boron nitride flakes, iron oxide nanoporous films, and organic-inorganic hybrid materials. The thermal conductivity of these materials is characterized by distinct trends, with some showcasing crystal-like behavior and others demonstrating glass-like characteristics. The analysis employs empirical expressions to discern the contributions of phonons and diffusons in crystal-like materials and incorporates Peierls contributions and Arrhenius-type terms for glass-like behavior. Noteworthy observations include deviations in fitting certain materials at lower temperatures and the identification of negative diffuson contributions in specific cases. These findings contribute to a nuanced understanding of thermal transport in nanostructured materials and have implications for applications in advanced thermal management systems and thermoelectric devices. The extracted parameters provide valuable insights for researchers exploring the thermal conductivity of diverse nanostructured materials. [ABSTRACT FROM AUTHOR]

Resonant-tunneling diodes (RTDs) based on Graphene nano-ribbons have attracted considerable attention from researchers in the electronics community in recent years. This paper proposes gate controllable armchair graphene RTD (GAG-RTD) structures based on Graphene nano-ribbon/h-Boron-Nitride hetero-structure. By increasing the gate width and putting a layer of h-BN in the graphene channel, we improved the peak-to-valley current ratio (PVR) by about 4–328 times compared to the previous study and also the power consumption decreased significantly. We achieved the power consumption of 3.56 nW and 18.76 nW at valley currents 2.49 nA and 13.7 nA, respectively, which are significantly better than many reported power in the literature. Also, we showed that some ranges of density of states (DOS) are almost non-transmission. Therefore, we divided the DOS into effective and non-effective parts. A numerical tight-binding model coupled with non-equilibrium Green's function (NEGF) formalism is employed for studying and simulation the electronic properties of these structures. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to investigate the effect of microtextured tools on the geometric morphology of serrated chips, and further improve the cutting performance of polycrystalline cubic boron nitride (PCBN) tool and extend the tool life and the surface quality of the machined surface. Design/methodology/approach: A three-dimensional finite element cutting model of hardened steel AISI D2 with microtextured PCBN tools were established using the finite element software Abaqus, and cutting tests were carried out. Furthermore, the stress distribution in the primary deformation zone was investigated based on the triaxiality of stress, and the influence of microtexture on the geometric morphology of serrated chips and crack development was researched. Findings: The results show that compared with nontexture tools, elliptical pits and wavy grooves microtexture tools have lower serrated degree Gs, higher serrated frequency f per unit length and more miniature serrated step Pc. The serrated phenomenon is intensified because the tensile stress zone of chips generated by nontextured tools is longer than that of elliptic pits and wavy grooves microtexture tools. Simultaneously, the maximum value of triaxiality in the tensile stress zone achieved by nontexture tools is larger than that of the two microtexture tools, and chips obtained by nontextured tools are more susceptible to propagation fractures. Originality/value: This paper mainly studies the effect of microtexture on chip microgeometry, which is relatively little studied at present. At the same time, this paper has a certain engineering significance for PCBN tool turning hardening steel. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0149/ [ABSTRACT FROM AUTHOR]

The particle size of powder coatings is an important factor affecting flow and fluidization performance, which in turn determines the quality of the coating. Powder coating particles, such as boron nitride, titanium dioxide, barium titanate, niobium oxide, and tungsten oxide, can be seen in SEM images as circular or polygonal shapes, with irregular edges and sizes, as well as aggregation and stacking between them. This paper introduces a novel method of automatic particle identification and size analysis applied in SEM images for the investigation of coating quality. Firstly, a fast gradient segmentation algorithm (Split–Merge) is utilized to automatically generate samples through determining the adhesive particles and particle groups. The samples are then manually checked and corrected to further segment the particles in order to form the dataset. Finally, the YOLOv5, a mature target detection algorithm, is used to train the labeled data in order to produce a multi-target detection recognition model. The model can be applied to identify more pictures of the same substance, and the particles' long and short axes are estimated using the elliptical coverage of the particles within the identified image boundary box. Experiment results from four kinds of powders suggest that this method can provide automatic particle size analysis for industrial SEM particle images. [ABSTRACT FROM AUTHOR]

In the present paper, we report polymer composites based on phenolic resin filled with hexagonal boron nitride; hot compression molding coupled with solution-based mixing were used to manufacture the composites. The paper presents experimental results on the physical and physicochemical properties of the obtained composites: thermal stability in air and argon, dielectric constant and dielectric loss tangent, active electrical resistance, thermal conductivity (mean and anisotropy), and mechanical strength. It is shown that the proposed technique of composite manufacturing, including the application of high-process pressures, makes it possible to obtain materials with high anisotropy of thermal conductivity, extremely high-filler content, and excellent dielectric properties, all of which are very important for prospective highly efficient lightweight heatsink elements for electronic devices. Experimental values of thermal conductivity and dielectric constant were analyzed using known mathematical models. Experimental values for thermal conductivities (up to 18.5 W·m−1·K−1) of composites at filler loadings of 65–85 vol.% are significantly higher than published data for bulk boron nitride/polymer composites. [ABSTRACT FROM AUTHOR]

The development of bio‐based polymer materials, such as polylactic acid (PLA) ‐based polymers, is an effective strategy to reduce dependence on petrochemical‐based polymers. However, the preparation of bio‐based polymers with high barrier properties is a major challenge. To overcome this challenge, a nacreous layer structure with a ' brick and mud ' pattern is mimicked to improve the overall performance of the material. In this paper, Poly (L‐lactic acid) (PLLA) and Polypropylene Glycol (PPG) was combined to prepare bio‐based polyurethane (PU‐PLLA), which is used as the slurry structure of nacreous layer. The bio‐based biomimetic composite membrane (PU‐PLLA/BN) is then obtained by adding boron nitride (BN, brick structure of pearl layer) to it. The water vapor permeability test results show that the permeability of PU‐PLLA material can be reduced by more than 50% by 5 wt.% BN, which is because the addition of BN can increase the length and tortuosity of the gas molecular diffusion path in the composite. Therefore, this pearl‐inspired PU‐PLLA/BN film has excellent moisture resistance, which opens up a broad road for the practical application of PLLA in flexible laminated packaging. [ABSTRACT FROM AUTHOR]

Acrylonitrile-butadiene-styrene (ABS) resin is a widely used engineering plastic at present. Due to its excellent mechanical properties and high fluidity, it is utilized in fused deposition molding (FDM) technology. In this paper, boron nitride nanosheets (BNNS) were prepared by hydrothermal exfoliation and used as nano-fillers for ABS resin, and ABS/BNNS composite wires for FDM printing were prepared by melt blending method. The results showed that BNNS with fewer layers were obtained; the addition of BNNS to the ABS resin matrix could effectively enhance the thermal conductivity of the composites. When the addition amount of BNNS was 15 wt%, the thermal conductivity of the composite increased to 0.369 W/(m K), which was 120.06 % higher than that of pure ABS (0.174 W/(m K)). In addition, BNNS also improves the mechanical properties, thermal stability, and melt flow rate of the composites, thus making ABS composite wires more suitable for FDM printing. [ABSTRACT FROM AUTHOR]

The paper presents a study on the magnetic characteristics of hexagonal boron nitride using Monte Carlo simulations through the Metropolis algorithm. The study used the Blume-Capel Ising model to analyze the behavior of magnetizations and susceptibilities under the effect of the temperature, mixed exchange coupling, crystalline and external magnetic fields. The results show that the blocking temperature, where the magnetic atoms become magnetically frozen, increases as the exchange coupling interaction becomes weaker and as the external magnetic field increases. The findings indicate that the blocking temperature of the system is significantly influenced by the physical parameters employed in this study. Besides, the investigation at hand could serve as a foundation for researchers to innovate novel categories of spintronics and magnetic memory devices, featuring enhanced performance and functionality. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to investigate the effect of doping element on the structural, thermal properties, mechanical performance and the failure mechanism of hexagonal nano boron nitride (h-BN)-reinforced basalt fabric (BF)/epoxy composites produced by hand lay-up and vacuum bagging technique. h-BN particles doped to composite materials increased the tensile, bending and impact strength of the composite at certain rates while 1 Wt. % h- BN addition shows the highest tensile and flexural strength. Design/methodology/approach: The epoxy resin was doped with h-BN nanopowder at the certain rates (0, 1, 2 and 4 Wt.%) and the epoxy: hardener ratios used in the study were selected as 80%: 20% by weight. Then, with the aid of a roller by hand lay-up method, a mixture of epoxy + hardeners containing nanoparticles and nanoparticle-free were fed onto BFs, 12 layers of each dimension 30 cm × 30 cm. The surplus epoxy resin was moved away from the composite sheets using the vacuum bagging process and left to cure at room temperature for 24 h. ASTM D3039 for tensile, D7264 for three-point bending and D256 for Izod impact test were performed for the mechanical tests. After the tensile test, the morphologies of the fracture surface were examined with a stereomicroscope and various failure mechanisms are highlighted. Findings: In this study, a series of basalt/epoxy composites with h-BN nanopowders have been prepared to identify the effect of filler ratio on mechanical properties. It has been known from the results of mechanical experiments that the addition of h-BN improves the mechanical performance of materials at a certain rate. The tensile and flexural strengths of h-BN doped composites, increase for concentrations of 1 Wt.% h-BN, but decrease with the increasing content of it. The basalt/epoxy resin composite with higher mechanical properties could be a potential material in the automotive and aerospace industries. Originality/value: The aim of this study is to contribute to literature within the context of this new combination of composites and their mechanical properties, failure mechanisms. It presents detailed characterization of each composite by using X-ray differaction (XRD), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

In this paper, nickel-clad cubic boron nitride (Ni/c-BN)-reinforced Ni-based composite coating was prepared on the martensitic stainless steel substrate by laser melting technology. The microstructure, phases and properties of the cladding layer were investigated by x-ray diffractometry, scanning electron microscopy, energy-dispersive spectrometry, microhardness test, wear test and potentio-dynamic polarization. The experimental results show that surface quality of the cladding was excellent and free of obvious defects when the Ni/c-BN content was 5 wt.%, while reticulation cracks appeared when the content was higher than 5 wt.%. In addition, compared with the coating without Ni/c-BN, the addition of Ni/c-BN made the coating form a new phase Ni3B and a change in the eutectic tissue in the coating, which was made up of γ-Ni, Ni3B and Ni4B3. After added Ni/c-BN, the hardness, wear resistance, and corrosion resistance of the coating increased first and then decreased. Excess Ni/c-BN reduced the solid solution B element content in the matrix and accelerates the formation of the crack of the coating, thereby deteriorating the hardness, wear resistance and corrosion resistance. The coating had the best hardness, wear resistance and corrosion resistance when the Ni/c-BN content was 5 wt.%. [ABSTRACT FROM AUTHOR]

We first constructed a new type of two-dimensional nanoribbon material by splicing a C2N-h2D nanoribbon with a BN nanoribbon, which is called the C2N-h2D/BN nanoribbon. The electronic properties of the C2N-h2D/BN nanoribbon were investigated using first-principles calculations, and its thermodynamic stability was verified through molecular dynamics simulations, demonstrating its dynamic stability at room temperature. Through analysis of the band structure, density of states, and charge density plots, we found that it is a nonmagnetic direct narrow bandgap semiconductor. To manipulate its electronic structure, we adsorbed transition metal atoms Mn, Fe, Co, and Ni into the nanoribbon. By analyzing the band structure and density of states after adsorption, we observed that the properties of the nanoribbon transitioned from a semiconductor to a metal upon adsorption of Mn, Co, and Ni atoms. Interestingly, after the adsorption of Fe atoms, the C2N-h2D/BN nanoribbon transformed from a semiconductor to a half-metal, indicating the generation of 100% spin-polarized current at the Fermi level and improved the electronic performance of the nanoribbon. This finding is exciting as it demonstrates that adsorption of different transition metal atoms can control the physicochemical properties of the nanoribbon, particularly the generation of 100% spin-polarized current at the Fermi level. This provides promising prospects for the application of this two-dimensional nanomaterial in spintronic devices and magnetic storage devices. [ABSTRACT FROM AUTHOR]

Synthesis of nanoscale materials is urgent with an increasing demand due to their valuable applications in various industries including medicine and aerospace. To advance green and sustainable nanomaterial synthesis, this study employed liquid-phase exfoliation techniques using bath sonication with gallnut and coffee waste as plant extracts to develop two-dimensional (2D) nanomaterials: functionalized few-layer graphene (FFG), h-boron nitride nanosheets (BNNs), functionalized few-layer borophene (FFB), and MXenes, from graphite, h-boron nitride, boron, and HF-etched Ti3AlC2, respectively, as well as their hybrids BNN/FFG, BNN/FFB, FFG/MXene, BNN/MXene, FFG/FFB, and FFB/MXene. When incorporated at 1 wt%, these nanomaterials and nanohybrids significantly improved both the mechanical properties and thermal stability of polyvinyl alcohol (PVA) and chitosan films. Specifically, the resulting hybrid nanocomposite films outperformed pure PVA in terms of tensile strength (35.1 ± 0.6 MPa) and Young's modulus (862.4 ± 42.4 MPa) with a 3.25- and 6.5-fold increase, respectively. In addition, the reinforcement of nanomaterials into the films increased the initial decomposition temperatures up to 50%. Furthermore, utilizing the graphene production process, we performed a life cycle assessment of this technology focusing on three impact categories: energy use, biogenicity, and land transformation. Commercial exfoliating solvents are much more costly than our plant extracts, according to an economic analysis of the costs related to the use of plant and coffee waste extracts in comparison to other exfoliating solvents. To date, this is the first study to successfully synthesize FFB, MXenes, and their hybrids with FFG and BNN using gallnut or coffee extract-mediated liquid phase exfoliation. The established method of nanohybrid preparation provides a simple, energy-efficient, and environmentally friendly approach that can be adapted for the design and synthesis of a wide range of functional hybrid nanomaterials with diverse applications. [ABSTRACT FROM AUTHOR]

With the increasing integration and power density of electronic and electrical equipment, highly thermally conductive insulating materials have a wide range of application scenarios. In this paper, a novel core-shell structure fiber thermal conductive filler hexagonal boron nitride@anatase titanium dioxide (h-BN@AT) has been prepared by electrospinning technology first. The h-BN@AT/epoxy resin (EP) thermally conductive and insulating composite was prepared by hot pressing. When the filler content was 30 wt%, the optimal thermal conductivity (γ) of h-BN@AT/EP composite was 7.62 W/(m.K) (in-plane) and 0.76 W/(m.K) (out-of-plane), which were 3088% and 324% higher than EP. The incorporation of high aspect ratio core-shell structural fibers significantly improves the efficiency of thermal conduction (TC) pathways formation within the composite. Moreover, the utilization of one-dimensional (1-D) anatase titanium dioxide fiber (ATO) and two-dimensional (2-D) boron nitride (h-BN) establishes a multi-level TC channel in EP, significantly increasing the of the composite. Notably, the composite retains outstanding insulation properties. The innovative core-shell structural fibers filler developed in this study provides a feasible method for producing thermal conductivity insulating materials. Highlights • A new type of core-shell structure h-BN@AT fiber filler is designed. • High thermal conductivity insulating composite h-BN@AT/EP are prepared by hot pressing. • h-BN@AT can effectively improve the thermal conductivity of composite to ensure good electrical properties. • The effect of h-BN content in h-BN@AT filler on the properties of the composite was obtained. • The superiority of h-BN@AT in heat conduction is verified by the classical heat conduction model and simulation. [ABSTRACT FROM AUTHOR]