The rapid development of industrialization requires the advancement of multifunctional coatings.In this study,successful self-assembly of iron porphyrin on BP nanosheets resulted in the synthesis of IBP nanosheets wit...The rapid development of industrialization requires the advancement of multifunctional coatings.In this study,successful self-assembly of iron porphyrin on BP nanosheets resulted in the synthesis of IBP nanosheets with a sandwich structure.Characterization tests including SEM,XPS,SPM,and XRD confirmed the successful preparation of IBP nanosheets with robust structural stability and antioxidation.Subsequently,a water-based epoxy resin(WEP)coating containing IBP nanosheets was prepared.Test results revealed that the composite coating containing 0.4 wt.%IBP nanosheets exhibited outstanding anti-corrosion,wear-resistant,and flame-retardant properties.After 42 days of immersion in a 3.5 wt.%NaCl solution,the Rct value of the 4-IBP/WEP coating was 1.79×10^(9)Ωcm^(2),surpassing the Pure WEP coating by more than 3 orders of magnitude.Additionally,the peak heat release rate(PHRR)and wear rate of the 4-IBP/WEP coating decreased by 19.29%and 90.97%compared to the Pure WEP coating.This research presents a novel idea for the utilization of BP nanosheets in multifunctional coatings.展开更多
The traditional inflexible electromagnetic interference(EMI)shielding materials have poor adaptability to wearable and portable flexible electronic devices due to their shortcomings such as brittleness and difficulty ...The traditional inflexible electromagnetic interference(EMI)shielding materials have poor adaptability to wearable and portable flexible electronic devices due to their shortcomings such as brittleness and difficulty in machinability.As an optimized alternative,the conductive polymer composites(CPCs)constructed by integrating MXene and polymer have become one of the most promising EMI shielding materials.To cope with the more harsh application conditions,the processing-structure-property relationship of MXene/polymer EMI shielding composites urgently needs to be clarified.In this review,the EMI shielding mechanism and theory of CPCs are first outlined.Then,the recent advances in processing strategies for MXene/polymer EMI shielding composites with different structures are comprehensively summarized,including layered structure,segregated structure,and porous structure.Next,the multifunctionality of MXene/polymer EMI shielding composites in hydrophobicity,flame retardancy,thermal conductivity,infrared thermal camouflage,electrothermal conversion,photothermal conversion,and sensing function,is systematically introduced.Finally,the prospects and challenges for the future development and application of multifunctional MXene/polymer EMI shielding composites are discussed.This review aims to put forward effective guidance for fabricating intelligent,adaptable,and integrated MXene/polymer EMI shielding composites,thus promoting the upgrading of advanced MXene-based CPCs.展开更多
The miniaturization and high-power density of electronic devices presents new challenges in thermal management.The precise control of microstructure arrangement,particularly in boron nitride nanosheets(BNNS),is essent...The miniaturization and high-power density of electronic devices presents new challenges in thermal management.The precise control of microstructure arrangement,particularly in boron nitride nanosheets(BNNS),is essential for achieving efficient heat dissipation in highly thermally conductive composites within electrically insulating package.In this work,manganese ferrite was hydrothermally synthesized on BNNS,creating a layered structure in a magnetically responsive nanohybrid material named BNNS@M.This material was then integrated into a waterborne polyurethane(WPU)solution and shaped under a magnetic field to produce thermally conductive film.By altering the magnetic field direction,the mi-crostructure orientation of BNNS@M was controlled,resulting in anisotropic thermally conductive com-posite films with horizontal and vertical orientations.Specifically,under a vertical magnetic field,the film 30-Ve-BNNS@WPU,containing 30 wt.%BNNS@M,achieved a through-plane thermal conductivity of 8.5 W m^(−1)K^(−1)and an in-plane thermal conductivity of 1.8 W m^(−1)K^(−1),showcasing significant anisotropic thermal conductivity.Meanwhile,these films demonstrated excellent thermal stability,mechanical per-formance,and flame retardancy.Furthermore,employing Foygel’s theory elucidated the impact of filler arrangement on thermal conductivity mechanisms and the actual application of 5 G device chips and LED lamps emphasizing the potential of these thermally conductive films in thermal management appli-cations.This investigation contributes valuable design concepts and foundations for the development of anisotropic thermally conductive composites suitable for electron thermal management.展开更多
The rapid development of industrialization necessitates advancements in nanomaterials.Black phospho-rus(BP)nanosheets have garnered extensive attention due to their highly anisotropic optoelectronic properties,high ca...The rapid development of industrialization necessitates advancements in nanomaterials.Black phospho-rus(BP)nanosheets have garnered extensive attention due to their highly anisotropic optoelectronic properties,high carrier mobility,and excellent mechanical properties.These unique attributes make BP nanosheets advantageous in various research fields.Combining BP nanosheets with polymers results in functional coatings and films with flame retardancy,antibacterial properties,wear resistance,and cor-rosion resistance.In this review,we first introduce various preparation methods for BP nanosheets.We discuss the degradation mechanisms of BP nanosheets and the passivation techniques employed to en-hance their environmental stability.Subsequently,we provide a detailed and comprehensive review of the applications of BP nanosheets in polymer coatings and films.Finally,we outline the development challenges and future research opportunities for BP-based polymer coatings and films.This article aims to summarize existing research and provide objective insights,serving as a constructive reference for the advancement of modern multifunctional polymer coatings and films.展开更多
In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functi...In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functional GO(fGO)used as nano-fillers for anti-corrosion enhancement of waterborne epoxy(WEP)coatings.Scanning electronic microscopy(SEM)images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics.UV-vis profiles demonstrate that fGO has p H-controlled release function.Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings.Modulus at lowest frequency(1.42×10^(5)Ωcm^(2))after 30 days immersion in 3.5 wt.%Na Cl solution revealed 2 orders of magnitude higher that of blank WEP(1.17×10^(7)Ωcm^(2)).With artificial cracks on its coatings,fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion.We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better,longer-lasting performance for shipping,oil drilling or bridge maintenance.展开更多
The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt...The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt%-12.0 wt%IFR and PLA together.The results of limiting oxygen index(LOI)and vertical burning(UL-94)discover that the combination of 0.5 wt%MXene and 11.5 wt%IFR synergistically improves the fire safety of PLA to reach UL-94 V-0 rating with LOI value of 33.0%.The PLA/IFR/MXene composites perform an obvious reduction in peak of heat release rate(HRR)in cone calorimeter tests(CCTs).Furthermore,the carbon residues after CCTs were characterized by scanning electron microscope(SEM),laser Raman spectroscopy(LRS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).It is demonstrated that both the titanium composition of the MXene structure and the characteristics of the two-dimensional material enhance the PLA/IFR/MXene composite materials’ability to produce a dense barrier layer to resist burnout during thermal degradation.展开更多
The risk of leakage and low thermal conductivity severely hinder the wide application of phase change materials(PCMs).In this work,the high-density polyethylene/carbon nanotubes(HDPE/CNTs)porous scaffolds were success...The risk of leakage and low thermal conductivity severely hinder the wide application of phase change materials(PCMs).In this work,the high-density polyethylene/carbon nanotubes(HDPE/CNTs)porous scaffolds were successfully fabricated via a sacrificial template method followed by the general melt blending and water solvent etching.Subsequently,a series of paraffin wax HDPE/CNTs/PW composite PCMs were obtained combined with the simple vacuum impregnation method.The obtained HDPE/CNTs porous scaffolds can effectively avoid the leakage of PW,meanwhile,the thermal conductivity and electrical conductivity of HDPE/CNTs/PW-3:7 are increased by 2.94 times and 13 orders of magnitude compared with the HDPE/PW-3:7 respectively,also,it exhibits high phase change enthalpy(153.95 J/g for melting enthalpy and 152.82 J/g for crystallization enthalpy).From the above perspectives,the HDPE/CNTs/PW-3:7 has promising potential value in the application of light-to-thermal conversion,electro-to-thermal conversion and thermal energy storage.展开更多
Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization.However,for organic solid-liquid PCMs,issues such as leakage,low th...Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization.However,for organic solid-liquid PCMs,issues such as leakage,low thermal conductivity,lack of efficient solar-thermal media,and flamma-bility have constrained their broad applications.Herein,we present an innova-tive class of versatile composite phase change materials(CPCMs)developed through a facile and environmentally friendly synthesis approach,leveraging the inherent anisotropy and unidirectional porosity of wood aerogel(nanowood)to support polyethylene glycol(PEG).The wood modification process involves the incorporation of phytic acid(PA)and MXene hybrid structure through an evaporation-induced assembly method,which could impart non-leaking PEG filling while concurrently facilitating thermal conduction,light absorption,and flame-retardant.Consequently,the as-prepared wood-based CPCMs showcase enhanced thermal conductivity(0.82 W m^(-1)K^(-1),about 4.6 times than PEG)as well as high latent heat of 135.5 kJ kg^(-1)(91.5%encapsula-tion)with thermal durability and stability throughout at least 200 heating and cooling cycles,featuring dramatic solar-thermal conversion efficiency up to 98.58%.In addition,with the synergistic effect of phytic acid and MXene,the flame-retardant performance of the CPCMs has been significantly enhanced,showing a self-extinguishing behavior.Moreover,the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs,relieving contemporary health hazards associated with electromagnetic waves.Overall,we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs,showcasing the operational principle through a proof-of-concept prototype system.展开更多
The development of miniaturized,flexible,and portable electronic devices has led to an increasing demand for multifunctional flexible films that can provide temperature regulation,electromagnetic interference(EMI)shie...The development of miniaturized,flexible,and portable electronic devices has led to an increasing demand for multifunctional flexible films that can provide temperature regulation,electromagnetic interference(EMI)shielding,and thermal management.In this study,a novel hierarchical multifunctional flexible composite film is presented.The first step involves the synthesis of phase change microcapsule(PCMC)latex through in-situ polymerization.Next,PCMC and waterborne polyurethane(WPU)latex were mixed and dried using a binary colloidal approach to produce a flexible composite phase change film(WPU/PCMC)with complete anti-leakage and satisfying melting enthalpy(147.86 J g^(-1)).To enhance the EMI performance and mechanical strength,a thin layer of antioxidant MXene@poly tannin acid(PTA)was directly sprayed onto the surface of WPU/PCMC,resulting in the WPU/PCMC/MXene@PTA film(WPM).Consequently,the WPM displays exceptional thermal management performance for multiple drives and outstanding EMI performance(56.86 dB),making it an ideal candidate for future multifunctional products.展开更多
Black phosphorus(BP),as one of the most promising fillers for flame retarding polymer,has been seriously limited in practical application,due to the agglomeration and poor structural stability challenges.Here,the BP w...Black phosphorus(BP),as one of the most promising fillers for flame retarding polymer,has been seriously limited in practical application,due to the agglomeration and poor structural stability challenges.Here,the BP was modified by MXene and polydopamine(PDA)via ultrasonication and dopamine modification strategy to improve the structural stability and dispersibility in the matrix.Then,the obtained(BP-MXene@PDA)nanohybrid was employed to promote the mechanical performance,thermal stability,and flame retardancy of thermoplastic polyurethane elastomer(TPU).The resultant TPU composite containing 2 wt.%of BP1-MXene2@PDA showed a 19.2%improvement in the tensile strength and a 13.8%increase in the elongation at break compared to those of the pure TPU.The thermogravimetric analysis suggested that BP-MXene@PDA clearly enhances the thermal stability of TPU composites.Furthermore,the introduction of the BP-MXene@PDA nanohybrids could considerably improve the flame retardancy of TPU composite,i.e.,64.2%and 27.3%decrease in peak heat release rate and total heat release,respectively.The flame-retardant mechanisms of TPU/BP-MXene@PDA in the gas phase and condensed phase were investigated systematically.This work provides a novel strategy to simultaneously enhance the fire safety and mechanical properties of TPU,thus expanding its industrial applications.展开更多
Microencapsulation of phase change materials(MPCM)is an effective way to achieve solar energy management.However,the crystallization of phase change materials(PCMs)in microcapsules will produce supercooling,which will...Microencapsulation of phase change materials(MPCM)is an effective way to achieve solar energy management.However,the crystallization of phase change materials(PCMs)in microcapsules will produce supercooling,which will affect the energy storage efficiency of MPCM.The incorporation of TiO_(2)nanoparticles into MPCM can alleviate supercooling.In this work,octadecyltrimethoxysilane(ODTMS)was used to modify the solid nucleating agent TiO_(2)(m-TiO_(2))to improve its compatibility with n-Octadecane.Then,MPCM based on m-TiO_(2)nucleating agent,melamine-formaldehyde resin(MF)shell material,and n-Octadecane core material was prepared.Differential scanning calorimetry(DSC)results demonstrate that the supercooling degree(ΔT)of MPCM(MPCM-02)decreases to 0℃with a tiny level of 0.25 wt%m-TiO_(2),while the MPCM with unmodified TiO_(2)is 6.1℃and the MPCM without nucleating agent is 4.1℃.Besides,the phase change enthalpy(ΔHm)and encapsulation efficiency(E)of MPCM-02 remain at 183.7 J/g and 95.3%,respectively.Finally,phase change composite materials with photothermal conversion capabilities were constructed by MXenes,MPCM,and polyurethane acrylate(PUA).When 1 wt%MXenes and 30 wt%MPCM were incorporated into PUA matrix,the thermal conductivity and surface temperature after 1200s of infrared light irradiation were 48.8%and 8.2℃higher than pure PUA matrix.These results demonstrate the good solar energy storage capabilities of the MPCM,which possesses promising application potential in the field of solar energy thermal management and human thermal regulation.展开更多
Contemporary industrial sectors are experiencing a growing imperative for coatings that exhibit a multi-tude of functions.In this study,PBP-Ce(Ш)nanosheets,characterized by robust structural stability,were synthesize...Contemporary industrial sectors are experiencing a growing imperative for coatings that exhibit a multi-tude of functions.In this study,PBP-Ce(Ш)nanosheets,characterized by robust structural stability,were synthesized using a one-pot method and incorporated into waterborne epoxy resin(WEP)to formu-late nanocomposite coatings.The findings demonstrate that the coating,containing 0.6 wt.%PBP-Ce(Ш)nanosheets,exhibits superb anti-corrosion,flame-retardant,and wear-resistant properties.Upon 42 days of 3.5%NaCl solution immersion,the fb of the 6-PBTC coating was a mere 3.55 Hz,significantly lower than the 309.51 Hz measured for the pure WEP coating.Furthermore,the Peak heat release rate(PHRR)of the microscale combustion calorimeter(MCC)and the wear rate of the 6-PBTC coating were reduced by 41.63%and 84.65%,respectively,in comparison to the pure WEP coating.This work not only delves into the utilization of BP nanosheets but also presents a viable solution for advancing the development of multifunctional coatings.展开更多
Efficient thermal management and electromagnetic interference(EMI)shielding are critical challenges for the reliable operation of portable electronic devices.Herein,we report the design and fabrication of multifunctio...Efficient thermal management and electromagnetic interference(EMI)shielding are critical challenges for the reliable operation of portable electronic devices.Herein,we report the design and fabrication of multifunctional layered composite phase change materials(CPCMs)comprising alternating cellulose nanofiber/phase change capsule/sodium alginate(CNF/PCC/SA)layers and MXene/sodium alginate(MXene/SA)layers.The strong interfacial adhesion and controlled multilayer architecture enable the CPCM to achieve high electrical conductivity(up to 279.8 S/cm)and excellent EMI shielding effectiveness(up to 57.6 dB in the X-band).The layered structure enhances electromagnetic wave attenuation via multiple internal reflections and polarization losses,outperforming homogeneous composites.Moreover,the CPCMs exhibit superior light absorption(maximum nearly 100% for the optimized 5-layer structure)and efficient light-to-thermal conversion,achieving rapid temperature increases and uniform heat distribution under light irradiation.Additionally,the phase change capsules enable latent heat storage,ensuring thermal buffering and prolonged temperature regulation.This work provides novel insights into the rational design of multifunctional composites integrating wireless thermal management and EMI shielding,with promising applications in wearable electronics and smart thermal regulation.展开更多
In this study,BP@ZIF-67(BZ),a special heterostructural nanofiller,was innovatively constructed by growing ZIF-67 in situ on black phosphorus(BP)nanosheets,and introduced it into the waterborne epoxy resin(WEP)coating....In this study,BP@ZIF-67(BZ),a special heterostructural nanofiller,was innovatively constructed by growing ZIF-67 in situ on black phosphorus(BP)nanosheets,and introduced it into the waterborne epoxy resin(WEP)coating.In addition,only 0.4 wt.%BZ nanofiller needs to be introduced to give the WEP coating an excellent overall performance improvement.After 42-day of immersion in 3.5 wt.%NaCl solution,the impedance modulus of 4-BZ/WEP in the low frequency region of 0.01 Hz(|Z0.01 Hz|)jumped two orders of magnitude compared to the pure WEP coating,showing a strong corrosion protection barrier effect;The wear rate of the 4-BZ/WEP coating is greatly reduced by 89.98%compared to the blank WEP coating,and the wear resistance has been qualitatively improved.And compare with the blank WEP coating,the peak heat release rate(PHRR)of the 4-BZ/WEP coating is reduced by 10.22%,effectively improving the fire safety and thermal stability of the material.The strategy of using BP nanosheets and ZIF-67 to construct multifunctional nanofillers provides a promising new way for the development of high-performance waterborne epoxy composite coatings that integrate long-term corrosion protection,high wear resistance and good flame retardancy.展开更多
With the rapid development of new generations of miniaturized,integrated,and high-power electronic devices,it is particularly important to develop advanced composite materials with efficient thermal management capabil...With the rapid development of new generations of miniaturized,integrated,and high-power electronic devices,it is particularly important to develop advanced composite materials with efficient thermal management capability and excellent electromagnetic interference(EMI)shielding performance.Herein,an innovative biomass/MXene-derived conductive hybrid scaffold,cellulose nanocrystal(CNC)-konjac glucomannan(KGM)/MXene(CKM),was prepared by freeze-drying and thermal annealing,and then paraffin wax(PW)was encapsulated in CKM using vacuum impregnation method to obtain CNC-KGM/MXene@PW phase change composites(CKMPCCs).The results show that the obtained CKMPCCs possess considerable reusable stabilities,excellent EMI shielding properties,and thermal energy management capacities.Among them,the CKMPCC-6 with 2.3 wt.%MXene exhibits excellent solar-thermal and electro-thermal conversion capabilities.In addition,the EMI shielding effectiveness value is as high as 45.0 dB at 8.2–12.4 GHz and the corresponding melting enthalpy value is 215.7 J/g(relative enthalpy efficiency of 99.9%).In conclusion,the synthesized multifunctional phase change composites provide great potential for integrating outstanding EMI shielding and advanced thermal energy management applications.展开更多
Design and exploitation of flame retardant polymers with high electrical conductivity are desired for polymer applications in electronics.Herein,a novel phosphorus-nitrogen intumescent flame retardant was synthesized ...Design and exploitation of flame retardant polymers with high electrical conductivity are desired for polymer applications in electronics.Herein,a novel phosphorus-nitrogen intumescent flame retardant was synthesized from pentaerythritol octahydrogen tetraphosphate,phenylphosphonyl dichloride,and aniline.Low-density polyethylene was combined with the flame retardant and multi-walled carbon nanotubes to form a nanocomposite material via a ball-milling and hot-pressing method.The electrical conductivity,mechanical properties,thermal performance,and flame retardancy of the composites were investigated using a four-point probe instrument,universal tensile machine,thermogravimetric analysis,and cone calorimeter tests,respectively.It was found that the addition of multi-walled carbon nanotubes can significantly improve the electrical conductivity and mechanical properties of the low-density polyethylene composites.Furthermore,the combination of multi-walled carbon nanotubes and phosphorus–nitrogen flame retardant remarkably enhances the flame retardancy of matrixes with an observed decrease of the peak heat release rate and total heat release of 49.8%and 51.9%,respectively.This study provides a new and effective methodology to substantially enhance the electrical conductivity and flame retardancy of polymers with an attractive prospect for polymer applications in electrical equipment.展开更多
Reversible addition-fragmentation chain transfer(RAFT)-mediated polymerization-induced self-assembly(PISA)of star block copolymer and linear block copolymer using a binary mixture of a star-like macro-RAFT agent and a...Reversible addition-fragmentation chain transfer(RAFT)-mediated polymerization-induced self-assembly(PISA)of star block copolymer and linear block copolymer using a binary mixture of a star-like macro-RAFT agent and a linear macro-RAFT agent is reported.With this formulation,star block copolymer and diblock copolymer were formed simultaneously to generate colloidally stable star/linear block copolymer assemblies.Size exclusion chromatography(SEC)analysis confirmed the presence of two types of polymers in the final samples.The molar ratio of the star-like macro-RAFT agent and the linear macro-RAFT agent has a significant impact on the morphology of polymer assemblies.It was found that increasing the amount of star-like macro-RAFT agent facilitated the formation of higher-order morphologies.Additionally,effects of other reaction parameters including the length/number of the arm of the star-like macro-RAFT agent,degree of polymer(DP),monomer concentration on the morphology of star/linear block copolymer assemblies were also investigated.We expect that this work will offer new possibilities for the scalable preparation of polymer assemblies with unique structures and functions.展开更多
基金supports from the Science and Technology Program of Guangzhou(No.2024A04J3710)the National Natural Science Foundation of China(No.22268025).
文摘The rapid development of industrialization requires the advancement of multifunctional coatings.In this study,successful self-assembly of iron porphyrin on BP nanosheets resulted in the synthesis of IBP nanosheets with a sandwich structure.Characterization tests including SEM,XPS,SPM,and XRD confirmed the successful preparation of IBP nanosheets with robust structural stability and antioxidation.Subsequently,a water-based epoxy resin(WEP)coating containing IBP nanosheets was prepared.Test results revealed that the composite coating containing 0.4 wt.%IBP nanosheets exhibited outstanding anti-corrosion,wear-resistant,and flame-retardant properties.After 42 days of immersion in a 3.5 wt.%NaCl solution,the Rct value of the 4-IBP/WEP coating was 1.79×10^(9)Ωcm^(2),surpassing the Pure WEP coating by more than 3 orders of magnitude.Additionally,the peak heat release rate(PHRR)and wear rate of the 4-IBP/WEP coating decreased by 19.29%and 90.97%compared to the Pure WEP coating.This research presents a novel idea for the utilization of BP nanosheets in multifunctional coatings.
基金financially supported by the National Natural Science Foundation of China(No.52436003)the Science and Technology Program of Guangzhou(No.2024A04J3710).
文摘The traditional inflexible electromagnetic interference(EMI)shielding materials have poor adaptability to wearable and portable flexible electronic devices due to their shortcomings such as brittleness and difficulty in machinability.As an optimized alternative,the conductive polymer composites(CPCs)constructed by integrating MXene and polymer have become one of the most promising EMI shielding materials.To cope with the more harsh application conditions,the processing-structure-property relationship of MXene/polymer EMI shielding composites urgently needs to be clarified.In this review,the EMI shielding mechanism and theory of CPCs are first outlined.Then,the recent advances in processing strategies for MXene/polymer EMI shielding composites with different structures are comprehensively summarized,including layered structure,segregated structure,and porous structure.Next,the multifunctionality of MXene/polymer EMI shielding composites in hydrophobicity,flame retardancy,thermal conductivity,infrared thermal camouflage,electrothermal conversion,photothermal conversion,and sensing function,is systematically introduced.Finally,the prospects and challenges for the future development and application of multifunctional MXene/polymer EMI shielding composites are discussed.This review aims to put forward effective guidance for fabricating intelligent,adaptable,and integrated MXene/polymer EMI shielding composites,thus promoting the upgrading of advanced MXene-based CPCs.
基金supported by the National Natural Science Foundation of China(No.22268025)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011985)the Applied Basic Research Program of Yunnan Province(Nos.202201AT070115,202201BE070001–031).
文摘The miniaturization and high-power density of electronic devices presents new challenges in thermal management.The precise control of microstructure arrangement,particularly in boron nitride nanosheets(BNNS),is essential for achieving efficient heat dissipation in highly thermally conductive composites within electrically insulating package.In this work,manganese ferrite was hydrothermally synthesized on BNNS,creating a layered structure in a magnetically responsive nanohybrid material named BNNS@M.This material was then integrated into a waterborne polyurethane(WPU)solution and shaped under a magnetic field to produce thermally conductive film.By altering the magnetic field direction,the mi-crostructure orientation of BNNS@M was controlled,resulting in anisotropic thermally conductive com-posite films with horizontal and vertical orientations.Specifically,under a vertical magnetic field,the film 30-Ve-BNNS@WPU,containing 30 wt.%BNNS@M,achieved a through-plane thermal conductivity of 8.5 W m^(−1)K^(−1)and an in-plane thermal conductivity of 1.8 W m^(−1)K^(−1),showcasing significant anisotropic thermal conductivity.Meanwhile,these films demonstrated excellent thermal stability,mechanical per-formance,and flame retardancy.Furthermore,employing Foygel’s theory elucidated the impact of filler arrangement on thermal conductivity mechanisms and the actual application of 5 G device chips and LED lamps emphasizing the potential of these thermally conductive films in thermal management appli-cations.This investigation contributes valuable design concepts and foundations for the development of anisotropic thermally conductive composites suitable for electron thermal management.
基金supported by the Science and Tech-nology Program of Guangzhou(No.2024A04J3710)the Na-tional Natural Science Foundation of China(No.22268025).
文摘The rapid development of industrialization necessitates advancements in nanomaterials.Black phospho-rus(BP)nanosheets have garnered extensive attention due to their highly anisotropic optoelectronic properties,high carrier mobility,and excellent mechanical properties.These unique attributes make BP nanosheets advantageous in various research fields.Combining BP nanosheets with polymers results in functional coatings and films with flame retardancy,antibacterial properties,wear resistance,and cor-rosion resistance.In this review,we first introduce various preparation methods for BP nanosheets.We discuss the degradation mechanisms of BP nanosheets and the passivation techniques employed to en-hance their environmental stability.Subsequently,we provide a detailed and comprehensive review of the applications of BP nanosheets in polymer coatings and films.Finally,we outline the development challenges and future research opportunities for BP-based polymer coatings and films.This article aims to summarize existing research and provide objective insights,serving as a constructive reference for the advancement of modern multifunctional polymer coatings and films.
基金supported by the National Natural Science Foundation of China(Grant No.51908031)the China Scholarship Council for a graduate fellowship(201906150013)+2 种基金the support from Guangdong Special Support Program(Grant No.2017TX04N371)ERC Enercapsule project(647969)Royal Society project IECR2202163。
文摘In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functional GO(fGO)used as nano-fillers for anti-corrosion enhancement of waterborne epoxy(WEP)coatings.Scanning electronic microscopy(SEM)images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics.UV-vis profiles demonstrate that fGO has p H-controlled release function.Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings.Modulus at lowest frequency(1.42×10^(5)Ωcm^(2))after 30 days immersion in 3.5 wt.%Na Cl solution revealed 2 orders of magnitude higher that of blank WEP(1.17×10^(7)Ωcm^(2)).With artificial cracks on its coatings,fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion.We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better,longer-lasting performance for shipping,oil drilling or bridge maintenance.
基金support from the National Natural Science Foundation of China(Grant Nos.21908031 and 51903092)the China Postdoctoral Science Foundation funded project(Grant No.2019M652884)support from Guangdong Special Support Program(Grant No.2017TX04N371)。
文摘The effect of Ti3C2 MXene nanosheets on the intumescent flame retardant(IFR)poly(lactic acid)(PLA)composites was investigated among a series of PLA/IFR/MXene,which were prepared by melt blending 0-2.0 wt%MXene,10.0 wt%-12.0 wt%IFR and PLA together.The results of limiting oxygen index(LOI)and vertical burning(UL-94)discover that the combination of 0.5 wt%MXene and 11.5 wt%IFR synergistically improves the fire safety of PLA to reach UL-94 V-0 rating with LOI value of 33.0%.The PLA/IFR/MXene composites perform an obvious reduction in peak of heat release rate(HRR)in cone calorimeter tests(CCTs).Furthermore,the carbon residues after CCTs were characterized by scanning electron microscope(SEM),laser Raman spectroscopy(LRS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).It is demonstrated that both the titanium composition of the MXene structure and the characteristics of the two-dimensional material enhance the PLA/IFR/MXene composite materials’ability to produce a dense barrier layer to resist burnout during thermal degradation.
基金supported by the National Natural Science Foundation of China(Grant No.51903092)support from Guangdong Special Support Program(Grant No.2017TX04N371)。
文摘The risk of leakage and low thermal conductivity severely hinder the wide application of phase change materials(PCMs).In this work,the high-density polyethylene/carbon nanotubes(HDPE/CNTs)porous scaffolds were successfully fabricated via a sacrificial template method followed by the general melt blending and water solvent etching.Subsequently,a series of paraffin wax HDPE/CNTs/PW composite PCMs were obtained combined with the simple vacuum impregnation method.The obtained HDPE/CNTs porous scaffolds can effectively avoid the leakage of PW,meanwhile,the thermal conductivity and electrical conductivity of HDPE/CNTs/PW-3:7 are increased by 2.94 times and 13 orders of magnitude compared with the HDPE/PW-3:7 respectively,also,it exhibits high phase change enthalpy(153.95 J/g for melting enthalpy and 152.82 J/g for crystallization enthalpy).From the above perspectives,the HDPE/CNTs/PW-3:7 has promising potential value in the application of light-to-thermal conversion,electro-to-thermal conversion and thermal energy storage.
基金funding from the National Natural Science Foundation of China(No.22268025)China Postdoctoral Science Foundation(NO.2022MD713757)+2 种基金Yunnan Provincial Postdoctoral Science Foundation(NO.34Y2022)Yunnan Province Joint Special Project for Enterprise Fundamental Research and Applied Basic Research(No.202101BC070001-016)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011985).
文摘Phase change materials(PCMs)offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization.However,for organic solid-liquid PCMs,issues such as leakage,low thermal conductivity,lack of efficient solar-thermal media,and flamma-bility have constrained their broad applications.Herein,we present an innova-tive class of versatile composite phase change materials(CPCMs)developed through a facile and environmentally friendly synthesis approach,leveraging the inherent anisotropy and unidirectional porosity of wood aerogel(nanowood)to support polyethylene glycol(PEG).The wood modification process involves the incorporation of phytic acid(PA)and MXene hybrid structure through an evaporation-induced assembly method,which could impart non-leaking PEG filling while concurrently facilitating thermal conduction,light absorption,and flame-retardant.Consequently,the as-prepared wood-based CPCMs showcase enhanced thermal conductivity(0.82 W m^(-1)K^(-1),about 4.6 times than PEG)as well as high latent heat of 135.5 kJ kg^(-1)(91.5%encapsula-tion)with thermal durability and stability throughout at least 200 heating and cooling cycles,featuring dramatic solar-thermal conversion efficiency up to 98.58%.In addition,with the synergistic effect of phytic acid and MXene,the flame-retardant performance of the CPCMs has been significantly enhanced,showing a self-extinguishing behavior.Moreover,the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs,relieving contemporary health hazards associated with electromagnetic waves.Overall,we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs,showcasing the operational principle through a proof-of-concept prototype system.
基金the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011985)the National Natural Science Foundation of China(No.U20A20299)the Scientific and Technological Innovation Strategy Program of Guangdong Province:Guangdong-Hong Kong-Macao Technology Cooperation Funding Scheme(No.2022A0505030026).
文摘The development of miniaturized,flexible,and portable electronic devices has led to an increasing demand for multifunctional flexible films that can provide temperature regulation,electromagnetic interference(EMI)shielding,and thermal management.In this study,a novel hierarchical multifunctional flexible composite film is presented.The first step involves the synthesis of phase change microcapsule(PCMC)latex through in-situ polymerization.Next,PCMC and waterborne polyurethane(WPU)latex were mixed and dried using a binary colloidal approach to produce a flexible composite phase change film(WPU/PCMC)with complete anti-leakage and satisfying melting enthalpy(147.86 J g^(-1)).To enhance the EMI performance and mechanical strength,a thin layer of antioxidant MXene@poly tannin acid(PTA)was directly sprayed onto the surface of WPU/PCMC,resulting in the WPU/PCMC/MXene@PTA film(WPM).Consequently,the WPM displays exceptional thermal management performance for multiple drives and outstanding EMI performance(56.86 dB),making it an ideal candidate for future multifunctional products.
基金supported by the National Natural Science Foundation of China(No.21908031)Scientific Research Funds of Yunnan Education Department(No.2021Y111)。
文摘Black phosphorus(BP),as one of the most promising fillers for flame retarding polymer,has been seriously limited in practical application,due to the agglomeration and poor structural stability challenges.Here,the BP was modified by MXene and polydopamine(PDA)via ultrasonication and dopamine modification strategy to improve the structural stability and dispersibility in the matrix.Then,the obtained(BP-MXene@PDA)nanohybrid was employed to promote the mechanical performance,thermal stability,and flame retardancy of thermoplastic polyurethane elastomer(TPU).The resultant TPU composite containing 2 wt.%of BP1-MXene2@PDA showed a 19.2%improvement in the tensile strength and a 13.8%increase in the elongation at break compared to those of the pure TPU.The thermogravimetric analysis suggested that BP-MXene@PDA clearly enhances the thermal stability of TPU composites.Furthermore,the introduction of the BP-MXene@PDA nanohybrids could considerably improve the flame retardancy of TPU composite,i.e.,64.2%and 27.3%decrease in peak heat release rate and total heat release,respectively.The flame-retardant mechanisms of TPU/BP-MXene@PDA in the gas phase and condensed phase were investigated systematically.This work provides a novel strategy to simultaneously enhance the fire safety and mechanical properties of TPU,thus expanding its industrial applications.
基金supported by the National Natural Science Foundation of China(No.U20A20299)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011985)the support from the Scientific and Technological Innovation Strategy Program of Guangdong Province:Guangdong-Hong Kong-Macao Technology Cooperation Funding Scheme(No.2022A0505030026).
文摘Microencapsulation of phase change materials(MPCM)is an effective way to achieve solar energy management.However,the crystallization of phase change materials(PCMs)in microcapsules will produce supercooling,which will affect the energy storage efficiency of MPCM.The incorporation of TiO_(2)nanoparticles into MPCM can alleviate supercooling.In this work,octadecyltrimethoxysilane(ODTMS)was used to modify the solid nucleating agent TiO_(2)(m-TiO_(2))to improve its compatibility with n-Octadecane.Then,MPCM based on m-TiO_(2)nucleating agent,melamine-formaldehyde resin(MF)shell material,and n-Octadecane core material was prepared.Differential scanning calorimetry(DSC)results demonstrate that the supercooling degree(ΔT)of MPCM(MPCM-02)decreases to 0℃with a tiny level of 0.25 wt%m-TiO_(2),while the MPCM with unmodified TiO_(2)is 6.1℃and the MPCM without nucleating agent is 4.1℃.Besides,the phase change enthalpy(ΔHm)and encapsulation efficiency(E)of MPCM-02 remain at 183.7 J/g and 95.3%,respectively.Finally,phase change composite materials with photothermal conversion capabilities were constructed by MXenes,MPCM,and polyurethane acrylate(PUA).When 1 wt%MXenes and 30 wt%MPCM were incorporated into PUA matrix,the thermal conductivity and surface temperature after 1200s of infrared light irradiation were 48.8%and 8.2℃higher than pure PUA matrix.These results demonstrate the good solar energy storage capabilities of the MPCM,which possesses promising application potential in the field of solar energy thermal management and human thermal regulation.
基金the National Natural Science Foundation of China(No.22268025)the Science and Tech-nology Program of Guangzhou(No.2024A04J3710)the Sci-entific and Technological Innovation Strategy Program of Guang-dong Province:Guangdong-Hong Kong-Macao Technology Cooper-ation Funding Scheme(No.2022A0505030026).
文摘Contemporary industrial sectors are experiencing a growing imperative for coatings that exhibit a multi-tude of functions.In this study,PBP-Ce(Ш)nanosheets,characterized by robust structural stability,were synthesized using a one-pot method and incorporated into waterborne epoxy resin(WEP)to formu-late nanocomposite coatings.The findings demonstrate that the coating,containing 0.6 wt.%PBP-Ce(Ш)nanosheets,exhibits superb anti-corrosion,flame-retardant,and wear-resistant properties.Upon 42 days of 3.5%NaCl solution immersion,the fb of the 6-PBTC coating was a mere 3.55 Hz,significantly lower than the 309.51 Hz measured for the pure WEP coating.Furthermore,the Peak heat release rate(PHRR)of the microscale combustion calorimeter(MCC)and the wear rate of the 6-PBTC coating were reduced by 41.63%and 84.65%,respectively,in comparison to the pure WEP coating.This work not only delves into the utilization of BP nanosheets but also presents a viable solution for advancing the development of multifunctional coatings.
基金the National Natural Science Foundation of China(No.52436003)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011985).
文摘Efficient thermal management and electromagnetic interference(EMI)shielding are critical challenges for the reliable operation of portable electronic devices.Herein,we report the design and fabrication of multifunctional layered composite phase change materials(CPCMs)comprising alternating cellulose nanofiber/phase change capsule/sodium alginate(CNF/PCC/SA)layers and MXene/sodium alginate(MXene/SA)layers.The strong interfacial adhesion and controlled multilayer architecture enable the CPCM to achieve high electrical conductivity(up to 279.8 S/cm)and excellent EMI shielding effectiveness(up to 57.6 dB in the X-band).The layered structure enhances electromagnetic wave attenuation via multiple internal reflections and polarization losses,outperforming homogeneous composites.Moreover,the CPCMs exhibit superior light absorption(maximum nearly 100% for the optimized 5-layer structure)and efficient light-to-thermal conversion,achieving rapid temperature increases and uniform heat distribution under light irradiation.Additionally,the phase change capsules enable latent heat storage,ensuring thermal buffering and prolonged temperature regulation.This work provides novel insights into the rational design of multifunctional composites integrating wireless thermal management and EMI shielding,with promising applications in wearable electronics and smart thermal regulation.
基金support from the Key Technology R&D Program of Yunnan Province(No.202403AA080008)Science and Technology Program of Guangzhou(No.2024A04J3710)。
文摘In this study,BP@ZIF-67(BZ),a special heterostructural nanofiller,was innovatively constructed by growing ZIF-67 in situ on black phosphorus(BP)nanosheets,and introduced it into the waterborne epoxy resin(WEP)coating.In addition,only 0.4 wt.%BZ nanofiller needs to be introduced to give the WEP coating an excellent overall performance improvement.After 42-day of immersion in 3.5 wt.%NaCl solution,the impedance modulus of 4-BZ/WEP in the low frequency region of 0.01 Hz(|Z0.01 Hz|)jumped two orders of magnitude compared to the pure WEP coating,showing a strong corrosion protection barrier effect;The wear rate of the 4-BZ/WEP coating is greatly reduced by 89.98%compared to the blank WEP coating,and the wear resistance has been qualitatively improved.And compare with the blank WEP coating,the peak heat release rate(PHRR)of the 4-BZ/WEP coating is reduced by 10.22%,effectively improving the fire safety and thermal stability of the material.The strategy of using BP nanosheets and ZIF-67 to construct multifunctional nanofillers provides a promising new way for the development of high-performance waterborne epoxy composite coatings that integrate long-term corrosion protection,high wear resistance and good flame retardancy.
基金the National Natural Science Foundation of China(No.U20A20299)Y.C.acknowledges the support from Guangdong Special Support Program(No.2017TX04N371).
文摘With the rapid development of new generations of miniaturized,integrated,and high-power electronic devices,it is particularly important to develop advanced composite materials with efficient thermal management capability and excellent electromagnetic interference(EMI)shielding performance.Herein,an innovative biomass/MXene-derived conductive hybrid scaffold,cellulose nanocrystal(CNC)-konjac glucomannan(KGM)/MXene(CKM),was prepared by freeze-drying and thermal annealing,and then paraffin wax(PW)was encapsulated in CKM using vacuum impregnation method to obtain CNC-KGM/MXene@PW phase change composites(CKMPCCs).The results show that the obtained CKMPCCs possess considerable reusable stabilities,excellent EMI shielding properties,and thermal energy management capacities.Among them,the CKMPCC-6 with 2.3 wt.%MXene exhibits excellent solar-thermal and electro-thermal conversion capabilities.In addition,the EMI shielding effectiveness value is as high as 45.0 dB at 8.2–12.4 GHz and the corresponding melting enthalpy value is 215.7 J/g(relative enthalpy efficiency of 99.9%).In conclusion,the synthesized multifunctional phase change composites provide great potential for integrating outstanding EMI shielding and advanced thermal energy management applications.
基金the National Natural Science Foundation of China(Grant Nos.21663015,21908031 and 51603096)Scientific Research Funds of Yunnan Education Department(Grant No.2021Y111).
文摘Design and exploitation of flame retardant polymers with high electrical conductivity are desired for polymer applications in electronics.Herein,a novel phosphorus-nitrogen intumescent flame retardant was synthesized from pentaerythritol octahydrogen tetraphosphate,phenylphosphonyl dichloride,and aniline.Low-density polyethylene was combined with the flame retardant and multi-walled carbon nanotubes to form a nanocomposite material via a ball-milling and hot-pressing method.The electrical conductivity,mechanical properties,thermal performance,and flame retardancy of the composites were investigated using a four-point probe instrument,universal tensile machine,thermogravimetric analysis,and cone calorimeter tests,respectively.It was found that the addition of multi-walled carbon nanotubes can significantly improve the electrical conductivity and mechanical properties of the low-density polyethylene composites.Furthermore,the combination of multi-walled carbon nanotubes and phosphorus–nitrogen flame retardant remarkably enhances the flame retardancy of matrixes with an observed decrease of the peak heat release rate and total heat release of 49.8%and 51.9%,respectively.This study provides a new and effective methodology to substantially enhance the electrical conductivity and flame retardancy of polymers with an attractive prospect for polymer applications in electrical equipment.
基金financially supported by the National Natural Science Foundation of China(U20A20299)Guangzhou Science and Technology Planning Project(202103000042)+3 种基金Guangdong Basic and Applied Basic Research Foundation(2019A1515011379)Guangdong Special Support Program(2017TX04N371)S&T Special Projects(SRPG22-020)Guangdong Enterprise Sci-tech Commissioner(GDKTP2020013400)。
基金the National Natural Science Foundation of China(Grant 22171055,52222301,and 21971047)the Guangdong Natural Science Foundation for Distinguished Young Scholar(Grant 2022B1515020078)the Science and Technology Program of Guangzhou(Grant SL2023A04J00142).
文摘Reversible addition-fragmentation chain transfer(RAFT)-mediated polymerization-induced self-assembly(PISA)of star block copolymer and linear block copolymer using a binary mixture of a star-like macro-RAFT agent and a linear macro-RAFT agent is reported.With this formulation,star block copolymer and diblock copolymer were formed simultaneously to generate colloidally stable star/linear block copolymer assemblies.Size exclusion chromatography(SEC)analysis confirmed the presence of two types of polymers in the final samples.The molar ratio of the star-like macro-RAFT agent and the linear macro-RAFT agent has a significant impact on the morphology of polymer assemblies.It was found that increasing the amount of star-like macro-RAFT agent facilitated the formation of higher-order morphologies.Additionally,effects of other reaction parameters including the length/number of the arm of the star-like macro-RAFT agent,degree of polymer(DP),monomer concentration on the morphology of star/linear block copolymer assemblies were also investigated.We expect that this work will offer new possibilities for the scalable preparation of polymer assemblies with unique structures and functions.
