Functionalized Boron Nitride Nanosheets Research Articles

Functionalized boron nitride nanosheets and their polypropylene nanocomposites: influence on thermal, mechanical, rheological and wear behaviour

ABSTRACT The few-layer hexagonal boron nitride (hBN) nanosheets with hydroxyl (−OH) functional group at edges are synthesized using heat treatment of micron size hBN powder followed by sonication. These nanosheets are modified with a silane coupling agent, 3-Aminopropyl,triethoxysilane (APTES). The synthesized hBN nanosheets are mixed with the PP matrix using twin-screw extrusion followed by injection moulding. In case of APTES-modified hBN nanosheets incorporation in the PP matrix with PP-grafted maleic anhydride (PP-g-MA) shows the formation of an imide bond between the MA functional group of PP-g-MA and the amine group of APTES modified hBN nanosheets revealing compatibilization. The flow behaviour index values are lower for hBN nanosheets filled PP nanocomposites showing the improved processability from Rheological characterization. The few-layered – OH and APTES modified hBN nanosheet incorporation in the PP matrix improves the tensile and thermal properties. The incorporation of APTES modified hBN nanosheet in the PP matrix shows an increase in tensile modulus (18.1%) and tensile strength (8.1%) respectively. Wear studies show the incorporation of – OH and APTES modified hBN nanosheets in the PP matrix decreases the coefficient of friction and wear rate significantly. The wear rate at 4 min of wear testing for modified hBN nanosheet in the PP nanocomposites is ~ 96% less in comparison with neat PP. The wear mechanism is established from wear measurements and scanning electron microscopy (SEM) of worn-out wear surfaces of PP nanocomposites.

Preparation of functionalized boron nitride nanosheets by one-step method for improving the thermal conductivity of polymers

Boron nitride nanosheets (BNNSs) with high thermal conductivity (TC) have promising applications in the thermal conduction. However, the preparation of BNNSs is cumbersome and BNNSs are prone to aggregation in the polymer matrix, which reduces the efficient enhancement for the TC of BNNSs/polymer composite. Herein, we propose a one-step method for the simultaneous exfoliation and functionalization of BNNSs with polymer latex as an agent. The obtained WPU-BNNSs displayed as few-layers with sizes of 100-500 nm and were mixed with WPU matrix as filler. The results demonstrated that the BNNSs/WPU composites have higher TC than the h-BN/WPU with the same filler content. When the filler content reached 50%, its TC was 251.4% higher than that of pure WPU. The excellent TC arose from the outstanding dispersion uniformity of WPU-BNNSs in the matrix. This study provides an economical and efficient method of fabricating BNNSs-based thermal conductive composite materials.

Oriented BN/BNNT heterostructure constructed by interface engineering strategy for polyamide-imide composite film with advanced flexibility and thermally conductive properties

Thermal conductive polymeric materials have aroused increasing attention as thermal management materials in the field of intelligent electronic devices due to their intriguing advantages. However, the discontinuity of phonon transmission path construction represents the bottleneck for thermal conductivity enhancement of composite materials, which limits the practical application of composite materials. Herein, flexible polyamide-imide (PAI) thermally conductive composite films with hierarchical structure composed of synergistically assembled functionalized boron nitride nanosheets (FBN) and polydopamine (PDA)-modified boron nitride nanotubes (FBT) by layer-by-layer assembly strategy are constructed. Benefitting from the optimized interface engineering with the ordered oriented arrangement FBN/FBT filler structure, the obtained composite film with optimized hybrid filler contents exhibits the super high thermal conductivity of 71.1 W·m−1·K−1, prominent thermal conductivity enhancement as high as 3663 % and excellent mechanical flexibility. The introduction of FBT can further expand the thermal contact area attributed to its inherent high thermal conductivity and aspect ratio. Additionally, the consecutive dual-channel phono transmission paths can be constructed in PAI composites under the synergistic action of FBN and FBT, further improving the phonon transmission density and suppressing phonon scattering, which endows PAI composite films with excellent thermal conductivity under low load of filler. The resulting multifunctionalities make the PAI composite films promising for flexible intelligent wearable electronic devices as thermal management materials.

Enhancing Thermal Conductivity in Epoxy Composites with Functionalized Boron Nitride Nanosheets

Enhancing Thermal Conductivity in Epoxy Composites with Functionalized Boron Nitride Nanosheets

Cetyl alcohol surface functionalization: a strategy for modulating electronic characteristics of boron nitride nanosheets

Hexagonal boron nitride (h-BN) is a two-dimensional material with a unique layered structure akin to Graphene. Cetyl alcohol (CH₃(CH₂)₁₅OH) denoted as CA, a fatty alcohol derived from natural sources like palm oil and coconut oil, holds a significant place in various industries due to its versatile properties. Cetyl alcohol's has a potential in forming stable nanostructures and its interactions with other compounds, shedding light on its utility in nanotechnology and materials science. In this work exfoliation of BNNS and subsequent functionalization using Cetyl alcohol is investigated. The functionalization of boron nitride nanosheets (BNNS) using CA is investigated in this study. The modification process aims to enhance the properties and applications of BNNS. OH groups are functionalized and bring about beneficial changes to its properties, enabling enhanced interactions with other compounds. This modification can lead to improved solubility, emulsification, and lubrication capabilities, expanding its utility in various applications such as cosmetics, pharmaceuticals, and industrial processes. Characterization techniques, including Thermogravimetric analysis(TG/DTA), UV-Visible spectroscopy, Photoluminescence, X- ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) are employed to analyze the efficacy of the functionalization process. Thermogravimetric-differential thermal analysis (TG-DTA) was utilized to investigate the thermal characteristics of the functionalized samples.

Facile synthesis of functionalized boron nitride nanosheets for photo‐cured 3D printing of high thermal conductive composites

AbstractAddressing the concern of heat accumulation in electronic devices, considerable research efforts have been dedicated to develop composites that are thermally conductive yet electrically insulative. Incorporating hexagonal boron nitride (h‐BN) as fillers shows promise in enhancing the thermal conductivity of polymer composites. However, notable challenges arise from difficulties in achieving well dispersion and establishing efficient three‐dimensional thermal conductive networks. This work demonstrated an efficient photocurable direct ink writing (DIW) printing method to fabricate functional h‐BN nanosheets (A‐BNNS)/epoxy acrylate (EA) resin‐based thermal conductive composites (A‐BNNS/EA). Apple polyphenol‐assisted ball milling was employed to fabricate functionalized BN nanosheets (A‐BNNS). Subsequently, A‐BNNS/EA inks were 3D printed using DIW to create thermally conductive composites, which were then UV‐cured. The composite containing 55 wt% A‐BNNS demonstrated an impressive thermal conductivity (TC) of 3.44 W/(m K). The utilization of 3D printing technology enables an onion‐like dispersion of A‐BNNS within the polymer matrix, effectively constructing three‐dimensional thermal conductive networks. This contribution significantly enhances the overall thermal conductivity.Highlights The functional BNNS (A‐BNNS) was achieved by apple polyphenol‐assisted ball milling. The utilization of photocurable 3D printing technology for producing high thermal conductivity materials are efficient. A‐BNNS exhibited an onion‐like distribution and effectively constructed a 3D thermal conductive network within the polymer matrix The composites demonstrate excellent thermal conductivity and favorable heat dissipation property.

Mechanically robust, transparent, and UV-shielding composite of Na-Alginate and maleic acid-functionalized boron nitride nanosheets with improved antioxidant property

Maleic acid functionalized boron nitride nanosheets (BNNS-MA)/Na-Alginate composite with enhanced mechanical, UV-shielding and antioxidation properties have been fabricated for the first time by solvent evaporation from a homogeneous aqueous dispersion of BNNS-MA/Na-Alginate composite solution. The composite fabrication was driven by homogenous nano-integrations and chemistry of compatibilization of BNNS-MA with Na-Alginate through H-bonding interactions between -COOH functional group of BNNS-MA and -OH, -COONa groups of Na-Alginate. The BNNS-MA/Na-Alginate composites show significant enhancement of mechanical, UV-blocking and antioxidant properties compared to the Na-Alginate. Integrating only 1 wt% BNNS-MA improved the UV-blocking, tensile strength, and antioxidant properties of Na-Alginate film by 99.1%, 73% and 60.3%, respectively. Overall, our findings of BNNS-MA integrated Na-Alginate composite films with improved physical, mechanical, UV shielding, and antioxidant functionalities is very promising to open new insight in the field of transparent UV-protected biopolymer film for consumer products, packaging, cosmetics, and engineering applications.

Insight into the interaction of pluronic F‐127 functionalized boron nitride nanosheets with piezoelectric poly(l‐lactic acid) nanofiber scaffolds for bone tissue engineering applications

AbstractOwing to their superior mechanical properties, good biocompatibility, biodegradability, and piezoelectric behavior, boron nitride (BN) nanostructures have received significant attention in the biomedical field, including filler in biopolymer composites, drug delivery, and cell stimulation. Nevertheless, the functionalization of BN is essential to overcome their strong agglomeration tendency in solvents and enhance their dispersibility and interfacial interaction with polymer matrix. Herein, we report an efficient dual functionalization approach for BN nanosheets (BNNS) using oleylamine (OLA) and pluronic F127 (PLU). First, BNNS has functionalized with OLA via Lewis acid–base interactions between the amino groups of OLA and the boron atoms of BNNS and then followed by PLU via noncovalent interactions. The composites of PLU‐functionalized boron nitride nanosheets (PLUBN) were reinforced into poly(l‐lactic acid) nanofiber (PLF) matrix, and subsequent changes in physiochemical, mechanical, and piezoelectric properties were reported in a concentration‐dependent manner. In addition, the density functional theory (DFT) calculations demonstrate the significant interaction between PLUBN and PLF. Further, in vitro studies with the preosteoblast (MC3T3‐T1) cells evidenced decent biocompatibility and proliferation with enhanced osteogenic differentiation potentials for the composite scaffolds. Thus, in the future, the reported effective strategy could be employed for preparing BNNS‐based piezoelectric biopolymer composites for tissue engineering applications.

Freeze-casting production of thermal insulating and fire-retardant lightweight aerogels based on nanocellulose and boron nitride

Cellulose aerogels exhibit biocompatibility and biodegradability, rendering them promising candidate for application in building energy conservation and insulation materials. However, the intrinsic inflammability of pristine cellulose aerogel causes unneglectable safety concerns, hindering their application in energy-efficient buildings. Herein, a thermal insulating, fire-retardant, strong, and lightweight aerogel was produced via freeze-casting suspensions of cellulose nanofibril (CNF) and l-glutamine functionalized boron nitride nanosheets (BNNS-g). The aerogel with a BNNS-g:CNF concentration ratio of 15:5 exhibited outstanding mechanical strength owing to the strong interaction between BNNS-g and CNF as well as satisfactory thermal insulating performance (0.052 W/m·K). Particularly, this aerogel showed excellent fire-retardant and self-extinguishing capabilities in the vertical burning test, which remained unscathed after over 60 s of burning in a butane flame. Further, the limit oxygen index (LOI) of this aerogel was 36.0 %, which was better than the LOIs of traditional petrochemical-based insulating materials. This study provides a promising strategy for producing aerogels with excellent properties using cellulose and other inorganic nano-fillers.

Coupling Anion‐Capturer with Polymer Chains in Fireproof Gel Polymer Electrolyte Enables Dendrite‐Free Sodium Metal Batteries

AbstractSodium metal batteries (SMBs) using gel polymer electrolytes (GPEs) with high theoretical capacity and low production cost are regarded as a promising candidate for high energy‐density batteries. However, the inherent flammability of GPEs and uncontrolled Na dendrite caused by inferior mechanical properties and interfacial stability hinder their practical applications. Herein, an anion‐trapping fireproof composite gel electrolyte (AT‐FCGE) is designed through a chemical grafting–coupling strategy, where functionalized boron nitride nanosheets (M‐BNNs) used as both nanosized crosslinker and anion capturer are coupled with poly(ethylene glycol)diacrylate in poly(vinylidene fluoride‐co‐hexafluoropropylene) matrix, to expedite Na+ transport and suppress dendrite growth. Experimental and calculation studies suggest that the anion‐trapping effect of M‐BNNs with abundant Lewis‐acid sites can promote the dissociation of salts, thus remarkably improving the ionic conductivity and Na+ transference number. Meanwhile, the formation of highly crosslinked semi‐interpenetrating network can effectively in situ encapsulate non‐flammable phosphate without sacrificing the mechanical properties. Consequently, the resulting AT‐FCGE shows significantly enhanced Na+ conductivity, mechanical properties, and excellent interfacial stability. The AT‐FCGE enables a long‐cycle stability dendrite‐free Na/Na symmetric cell, and prominent electrochemical performance is demonstrated in solid‐state SMBs. The approach provides a broader promise for the great potential of fire‐retardant gel electrolytes in high‐performance SMBs and the beyond.

Flexible and thermally conductive epoxy‐dispersed liquid crystal composites filled with functionalized boron nitride nanosheets

AbstractIn view of the problem of heat accumulation in electronic devices, the development of new composites with high thermal conductivity (TC) is the current research focus. Nowadays, improving TC often lead to inevitable deterioration of the mechanical properties of materials. In this work, the E‐functionalized boron nitride nanosheets (f‐BNNS)/liquid crystal monomer (LCM)/Epoxy‐thiol films with high TC were prepared by using flexible epoxy‐thiol polymer as matrix and LCM and f‐BNNS as thermal fillers via high voltage orientation molding. The epoxy‐thiol polymer possessed high intrinsic TC due to the regular arrangement of molecular chains and the f‐BNNS showed favorable dispersibility because of the modification by isopropyl tri(dioctylpyrophosphate) titanate (ITDPT). The results show that TC of E‐f‐BNNS/LCM/Epoxy‐thiol films with 30 wt% f‐BNNS content achieves 1.65 W/m·K and is 511.11% higher than that of pure epoxy‐thiol polymer (0.27 W/m·K). The tensile strength and elongation at break increase to 24.9 MPa and 47.41%, respectively. The favorable results are attributed to the ordered arrangement of f‐BNNS and molecular chains, resulting from the hydrogen‐bonding interaction between OH group in f‐BNNS, LCM and epoxy‐thiol polymer. This research provides a simple and feasible method for preparing flexible epoxy polymer films with high TC.Highlights The functional BNNS was achieved by isopropyl tri(dioctylpyrophosphate) titanate. Effects of matrix thermal conductivity on films thermal conductivity are probed. High voltage orientation molding are used for preparing epoxy composite films. The films demonstrate excellent thermal conductivity and favorable tensile strength.

Microfluidic-Assisted Self-Assembly of 2D Nanosheets toward in situ Generation of Robust Nanofiber Film.

Methods allow the enhancement of nanofibers via self-assembly are potentially important for new disciplines with many advantages, including multi-anchor interaction, intrinsic mechanical properties and versatility. Herein, a microfluidic-assisted self-assembly process to construct hydroxyl functionalized boron nitride nanosheets (OH-BNNS)/graphene oxide (GO)/thermoplastic polyurethane (TPU) composite nanofiber film, in which stable and precisely controlled self-assembly is fulfilled by the confined ultra-small-volume chip is demonstrated. Multiple fine structural analyses alongside with the density-functional theory (DFT) calculations are implemented to confirm the synergistic effect of noncovalent interactions (hydrogen bonding interaction, π - π stacking interaction, and van der Waals attraction) plays a critical role in the robust micro-structure and a massive 700% enhancement of mechanical strength via adding only 0.3wt% OH-BNNS and GO. Importantly, profiled from broadband optical absorption ability, robust mechanical properties and outstanding flexibility, the self-assembled 3D OH-BNNS/GO/TPU nanofiber film reveals an adorable evaporation rate of 4.04kgm-2 h-1 under one sun illumination with stable energy transfer efficiency (93.2%) by accompanying hydrogen bonding interaction. This microfluidic-assisted self-assembly strategy will provide a constructive entry point for the rational design of nanofibers and beyond.

Novel Functionalized Boron Nitride Nanosheets Achieved by Radiation-Induced Oxygen Radicals and Their Enhancement for Polymer Nanocomposites.

Boron nitride nanosheets (BNNSs) exfoliated from hexagonal boron nitride (h-BN) show great potential in polymer-based composites due to their excellent mechanical properties, highly thermal conductivity, and insulation properties. Moreover, the structural optimization, especially the surface hydroxylation, of BNNSs is of importance to promote their reinforcements and optimize the compatibility of its polymer matrix. In this work, BNNSs were successfully attracted by oxygen radicals decomposed from di-tert-butylperoxide (TBP) induced by electron beam irradiation and then treated with piranha solution. The structural changes of BNNSs in the modification process were deeply studied, and the results demonstrate that the as-prepared covalently functionalized BNNSs possess abundant surface hydroxyl groups as well as reliable structural integrity. Of particular importance is that the yield rate of the hydroxyl groups is impressive, whereas the usage of organic peroxide and reaction time is greatly reduced due to the positive effect of the electron beam irradiation. The comparisons of PVA/BNNSs nanocomposites further indicate that the hydroxyl-functionalized BNNSs effectively promote mechanical properties and breakdown strength due to the enhanced compatibility and strong two-phase interactions between nanofillers and the polymer matrix, which further verify the application prospects of the novel route proposed in this work.

Novel multifunctional melamine borate - boron nitride nanosheets/epoxy composites with enhanced thermal conductivity, flame retardancy and satisfying electrical insulation

In this work, we present a solution to use nitrogen and boron co-effect flame-retardant (melamine borate, abbreviated as MB) functionalized boron nitride nanosheets (MB-BNNS) to improve the thermal conductivity and flame retardance of epoxy resin and maintain excellent electrically insulating properties simultaneously. In brief, the MB-BNNS were prepared by grafting MB onto boron nitride surfaces via a simple ball-milling and eco-friendly water scrubbing process. Subsequently, the epoxy composites with uniformly dispersed MB-BNNS were obtained by wet processing. The obtained epoxy composite with 5 vol% EP/MB-BNNS showed a optimally comprehensive performance. Compared to pure epoxy, it showed 108% of increase in thermal conductivity (TC), 36.44% and 32.06% of decrease in peak heat release rate (PHRR) and total heat release rate (THR), and slightly decrease in dielectric breakdown strength. More remarkably, the release percentages of toxic and combustible gases in EP/MB-BNNS composite system were significantly reduced, which were measured by a in-situ measurement.

One-step hydrothermal approach for synthesis of hydroxy functionalized boron nitride nanosheets for fluorescence detection of uric acid in biological samples

One-step hydrothermal approach for synthesis of hydroxy functionalized boron nitride nanosheets for fluorescence detection of uric acid in biological samples

Highly dispersed and functionalized boron nitride nanosheets contribute to ultra-stable long-life all-solid-state batteries

Highly dispersed and functionalized BNNSs contribute to ultra-stable long life all-solid-state batteries.

Functionalized boron nitride nanosheets conjugated with plant micronutrients as seed dressing agents towards control of bacterial wilt disease

A novel strategy for bacterial wilt disease control was proposed involving boron nitride nanosheets to immobilize plant micronutrients and form a defensive barrier in plant roots to block or inhibit the invasion of pathogen.

Flexible nanocellulose-based layered films by crosslinking phosphorus lignin nanoparticles and functionalized boron nitride nanosheets for flame-resistant and thermal conductivity applications

This work reports the preparation of nanocellulose-based thermal conductivity and flame-retardant dual-function composites for use in thermal management applications for flexible electronic devices.

Physicochemical and biological assessment of boron nitride nanosheets-reinforced poly(2-hydroxyethylmethacrylate) composite for biomedical applications

Research on mechanically advanced materials for biological applications involving load-bearing is in progress. Within this scope, this study is the first to propose the fabrication of bionanocomposites combining the different amounts of functionalized boron nitride nanosheets (f-BNNSs, 0-2.0 mg/mL) and poly(hydroxyethyl methacrylate) (pHEMA). The pristine BN was exfoliated by microwave irradiation to access BNNSs at different powers and times. The as-exfoliated BNNSs were characterized by zeta-sizer, FTIR, XRD, and TEM, which showed that the BNNSs exhibited facile and processable features in tiny sizes. Bionanocomposites were fabricated by photopolymerization. The physical, chemical, and mechanical properties, hydrophilic behavior, and degradability of bionanocomposites were evaluated. The mechanical parameters such as Young’s modulus and elongation percentage at break showed that adding f-BNNSs up to 2.0 mg/mL significantly increased the mechanical strength of pHEMA without affecting the hydrophilicity, hemocompatibility, and cytotoxicity. Moreover, the hardness of pHEMA/f-BNNSs composites (38.56 MPa) was remarkably higher than that of pHEMA. There was no cytotoxicity recorded for fabricated bionanocomposites from the MTT assay. All nanocomposites exhibited superior antibacterial activities against E.coli and S.aureus compared with pHEMA. However, pHEMA/f-BNNSs composites were more effective against E.coli than S.aureus . While E.coli colonies was reduced 100% at all composites in an hour, S.aureus colonies was completely destroyed with pHEMA/1f-BNNSs and pHEMA/2f-BNNSs after 24 h incubation. The study's findings demonstrated that the mechanically improved pHEMA/f-BNNSs films could increase the application of pHEMA in biomedical fields.

Review of boron nitride-based membranes in liquid purification/separation applications

Boron nitride (BN) has been drawing significant interest in environmental applications owing to its distinct properties, such as a large surface area, great chemical/mechanical strength, and abundant structural defects. BN-based membranes have been utilized in various liquid purification/separation applications associated with reverse osmosis (RO), nanofiltration (NF), and ultrafiltration (UF). A small number of review studies have been published on the environmental applications of BN-based membranes, including water purification and desalination. However, further studies are vital to gain the comprehensive understanding needed to assess the removal/separation mechanisms in BN-based membranes, although existing reviews cover the water desalination, antibacterial performance, and/or energy applications of BN-based membranes. Therefore, in this review, we provide an overview of the various types of BNs (e.g., functionalized BN nanosheets, nanotubes, and nanofibers) incorporated into RO, NF, and UF membranes. Next, we discuss the fabrication and separation performance of various BN-based membranes. In particular, this review focuses on various main factors, namely, the fabrication techniques of BN-based membranes, membrane physicochemical properties, and contaminant properties that affect the transport, separation, and membrane flux during the use of BN-based membrane processes. Finally, prospective study areas are presented briefly.