The morphological distribution of absorbent in composites is equally important with absorbents for the overall electromagnetic properties,but it is often ignored.Herein,a comprehensive consideration including electrom...The morphological distribution of absorbent in composites is equally important with absorbents for the overall electromagnetic properties,but it is often ignored.Herein,a comprehensive consideration including electromagnetic component regulation,layered arrangement structure,and gradient concentration distribution was used to optimize impedance matching and enhance electromagnetic loss.On the microscale,the incorporation of magnetic Ni nanoparticles into MXene nanosheets(Ni@MXene)endows suitable intrinsic permittivity and permeability.On the macroscale,the layered arrangement of Ni@MXene increases the effective interaction area with electromagnetic waves,inducing multiple reflection/scattering effects.On this basis,according to the analysis of absorption,reflection,and transmission(A-R-T)power coefficients of layered composites,the gradient concentration distribution was constructed to realize the impedance matching at low-concentration surface layer,electromagnetic loss at middle concentration interlayer and microwave reflection at high-concentration bottom layer.Consequently,the layered gradient composite(LG5-10-15)achieves complete absorption coverage of X-band at thickness of 2.00-2.20 mm with RL_(min) of-68.67 dB at 9.85 GHz in 2.05 mm,which is 199.0%,12.6%,and 50.6%higher than non-layered,layered and layered descending gradient composites,respectively.Therefore,this work confirms the importance of layered gradient structure in improving absorption performance and broadens the design of high-performance microwave absorption materials.展开更多
With the rapid development of wearable electronic skin technology, flexible strain sensors have shown great application prospects in the fields of human motion and physiological signal detection, medical diagnostics, ...With the rapid development of wearable electronic skin technology, flexible strain sensors have shown great application prospects in the fields of human motion and physiological signal detection, medical diagnostics, and human-computer interaction owing to their outstanding sensing performance. This paper reports a strain sensor with synergistic conductive network, consisting of stable carbon nanotube dispersion (CNT) layer and brittle MXene layer by dip-coating and electrostatic self-assembly method, and breathable three-dimensional (3D) flexible substrate of thermoplastic polyurethane (TPU) fibrous membrane prepared through electrospinning technology. The MXene/CNT@PDA-TPU (MC@p-TPU) flexible strain sensor had excellent air permeability, wide operating range (0–450 %), high sensitivity (Gauge Factor, GFmax = 8089.7), ultra-low detection limit (0.05 %), rapid response and recovery times (40 ms/60 ms), and excellent cycle stability and durability (10,000 cycles). Given its superior strain sensing capabilities, this sensor can be applied in physiological signals detection, human motion pattern recognition, and driving exoskeleton robots. In addition, MC@p-TPU fibrous membrane also exhibited excellent photothermal conversion performance and can be used as a wearable photo-heater, which has far-reaching application potential in the photothermal therapy of human joint diseases.展开更多
As living standards improve,the energy consumption for regulating indoor temperature keeps increasing.Windows,in particular,enhance indoor brightness but also lead to increased energy loss,especially in sunny weather....As living standards improve,the energy consumption for regulating indoor temperature keeps increasing.Windows,in particular,enhance indoor brightness but also lead to increased energy loss,especially in sunny weather.Developing a product that can maintain indoor brightness while reducing energy consumption is a challenge.We developed a facile,spectrally selective transparent ultrahigh-molecular-weight polyethylene composite film to address this trade-off.It is based on a blend of antimony-doped tin oxide and then spin-coated hydrophobic fumed silica,achieving a high visible light transmittance(>70%)and high shielding rates for ultraviolet(>90%)and near-infrared(>70%).When applied to the acrylic window of containers and placed outside,this film can cause a 10℃ temperature drop compared to a pure polymer film.Moreover,in building energy simulations,the annual energy savings could be between 14.1%~31.9%per year.The development of energy-efficient and eco-friendly transparent films is crucial for reducing energy consumption and promoting sustainability in the window environment.展开更多
Two-dimensional transition metal carbon/nitrides(MXenes)have emerged as prominent materials in the development of high-performance electromagnetic interference(EMI)shielding films owing to their ex-ceptional electrica...Two-dimensional transition metal carbon/nitrides(MXenes)have emerged as prominent materials in the development of high-performance electromagnetic interference(EMI)shielding films owing to their ex-ceptional electrical conductivity,special layered structure,and chemically active surfaces.Substantial ef-forts have been devoted to addressing the poor mechanical strength and limited functionality of pure MXene films through structural design and interfacial reinforcement.However,there is a notable lack of a systematic review of the research on MXene-based EMI shielding films with multi-layer structures,which could provide a theoretical foundation and technical guidance for the development and application of shielding films.This review aims to summarize the recent advancements in MXene-based layered films for EMI shielding.First,the structure and properties of MXene nanosheets are systematically introduced.Next,the optimization of layered structures and interfacial reinforcement strategies in MXene-based EMI shielding films are objectively reviewed,followed by a discussion of their multifunctional compatibility.Finally,future prospects and challenges for MXene-based layered EMI shielding films are highlighted.展开更多
The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials.However,the pursuit of sustained antibacter...The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials.However,the pursuit of sustained antibacterial efficacy remains a formidable challenge.In this context,we proposed a novel strategy that leverages swelling and erosion mechanisms to facilitate drug release of drug-loaded ultrahigh molecular weight polyethylene(UHMWPE),thereby ensuring its long-lasting antibacterial performance.Polyethylene oxide(PEO),a hydrophilic polymer with fast hydrating ability and high swelling capacity,was incorporated in UHMWPE alongside the antibacterial tea polyphenol(epigallocatechin gallate,EGCG as representative).The swelling of PEO enhanced water infiltration into the matrix,while the erosion of PEO balanced the release of the encapsulated EGCG,resulting in a steady release.The behavior was supported by the EGCG release profiles and the corresponding fitted release kinetic models.As demonstrated by segmented antibacterial assessments,the antibacterial efficiency was enhanced 2to 3 times in the PEO/EGCG/UHMWPE composite compared to that of EGCG/UHMWPE.Additionally,the PEO/EGCG/UHMWPE composite exhibited favorable biocompatibility and mechanical performance,making it a potential candidate for the development of drug-releasing joint implants to combat prosthetic bacterial infections.展开更多
The service life and properties of Carbon fiber reinforced polycarbonate (CF/PC) composites are seriously affected by ultraviolet radiation from outdoor exposure during aging. In this work, the changes of structure an...The service life and properties of Carbon fiber reinforced polycarbonate (CF/PC) composites are seriously affected by ultraviolet radiation from outdoor exposure during aging. In this work, the changes of structure and solid particle erosion resistance for CF/PC composites after ultraviolet irradiation were studied. It was shown that ultraviolet irradiation causes photo-oxygen aging and photo-fries re-arrangement of the composite, and the result was confirmed by FTIR. We correlated the solid particle erosion resistance with aging time, and found that the solid particle erosion resistance of CF/PC composites greatly decreased by UVB irradiation during 15 hours. Furthermore, the eroded material surface was analyzed using scanning electron microscope (SEM). It suggests that ultraviolet aging leads to plasticization and degradation, resulting in reduction of erosion resistance of the composite.展开更多
The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot.Here,the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of mela...The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot.Here,the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of melamine foam(MF)through electrostatic self-assembly and dip-coating adsorption process,realizing the integration of microwave absorption,infrared stealth,and flame retardant.Remarkably,the Ni/MXene-MF achieves a minimum reflection loss(RLmin)of−62.7 dB with a corresponding effective absorption bandwidth(EAB)of 6.24 GHz at 2 mm and an EAB of 6.88 GHz at 1.8 mm.Strong electromagnetic wave absorption is attributed to the three-dimensional magnetic/conductive networks,which provided excellent impedance matching,dielectric loss,magnetic loss,interface polarization,and multiple attenuations.In addition,the Ni/MXene-MF endows low density,excellent heat insulation,infrared stealth,and flame-retardant functions.This work provided a new development strategy for the design of multifunctional and efficient electromagnetic wave absorbing materials.展开更多
With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel(CA) with highly enhanced thermal conductivity(TC) in vertical...With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel(CA) with highly enhanced thermal conductivity(TC) in vertical planes was successfully obtained by constructing a vertically aligned silicon carbide nanowires(SiC NWs)/boron nitride(BN) network via the ice template-assisted strategy. The unique network structure of SiC NWs connected to BN ensures that the TC of the composite in the vertical direction reaches 2.21 W m^(-1) K^(-1) at a low hybrid filler loading of 16.69 wt%, which was increased by 890% compared to pure epoxy(EP). In addition, relying on unique porous network structure of CA, EP-based composite also showed higher TC than other comparative samples in the horizontal direction. Meanwhile, the composite exhibits good electrically insulating with a volume electrical resistivity about 2.35 × 10^(11) Ω cm and displays excellent electromagnetic wave absorption performance with a minimum reflection loss of-21.5 dB and a wide effective absorption bandwidth(<-10 dB) from 8.8 to 11.6 GHz. Therefore, this work provides a new strategy for manufacturing polymer-based composites with excellent multifunctional performances in microelectronic packaging applications.展开更多
Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost ...Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost catalysts for OER process is essential as the conventional catalysts still rely on precious metals.Transition metal-based compounds have been widely investigated as active OER catalysts,and renewed interest in the high valence metals engineered compounds has been achieved for superior catalytic activity and stability.However,an in-depth understanding of the construction strategies and induced effects for the high valence metals engineered catalysts is still lacking and desired.In this review,we have summarized the construction strategies of high valence metals as dopants or formed heterostructures with the iron/cobalt/nickel(Fe/Co/Ni)-based catalysts.Then the induced effects on Fe/Co/Ni-based catalysts by incorporating high valence metals,e.g.,accelerating the surface reconstruction,forming amorphous structure,generating vacancies/defects,and acting as stabilizers,are highlighted.The impacts of high valence metals on OER performance are elucidated based on different elements,including molybdenum(Mo),tungsten(W),cerium(Ce),vanadium(V),chromium(Cr),manganese(Mn),niobium(Nb),zirconium(Zr).The correlations of construction strategies,induced effects,catalytic activity and OER reaction pathways are elaborated.Finally,the remaining challenges for further enhancements of OER performance induced by high valence metals are presented.展开更多
Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,t...Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,there is still a lack of a green and facile way to prepare PLA oil-water separation materials.In this work,a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported.The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight.In addition,it could also be applicated as a filter with excellent efficiency(50.9 m^3 m^(-2) h^(-1)).展开更多
With the discovery of the two-dimensional(2D) MXene, it shows a great application potential in the field of electromagnetic interference(EMI) shielding, but the mechanical brittleness and easy oxidation of MXene limit...With the discovery of the two-dimensional(2D) MXene, it shows a great application potential in the field of electromagnetic interference(EMI) shielding, but the mechanical brittleness and easy oxidation of MXene limit its wide application. For this reason, a double crosslinking strategy is provided to solve the above problems in a nacre-like “brick-mortar” layered MXene/cellulose nanofiber(MXene/CNF) film.Typically, the film was firstly suffered by dopamine modification, then was further reinforced by secondary Ca^(2+)bridging, so as to obtain excellent mechanical properties and antioxidative EMI shielding performance. Comparing with the single crosslinking, the double crosslinking strategy reveals a higher efficiency in improving the mechanical property. The mechanical strength and toughness of the double crosslinking MXene/CNF film can increase to 142.2 MPa and 9.48 MJ/m^(3), respectively. More importantly, while achieving good mechanical properties, the MXene composite film still holds a very stable EMI shielding performance of more than 44.6 dB when suffering from the oxidation treatment of hightemperature annealing, showing excellent anti-oxidation ability and environment tolerance. Therefore,this work provides a universal but effective double crosslinking strategy to solve the mechanical brittleness and easy oxidation of MXene-based composites, thus showing a huge potential in flexible EMI shielding applications.展开更多
Ultra-thin flexible films have attracted wide attention because of their excellent ductility and potential versatility.In particular,the energy-harvesting films(EHFs)have become a research hotspot because of the indis...Ultra-thin flexible films have attracted wide attention because of their excellent ductility and potential versatility.In particular,the energy-harvesting films(EHFs)have become a research hotspot because of the indispensability of power source in various devices.However,the design and fabrication of such films that can capture or transform di erent types of energy from environments for multiple usages remains a challenge.Herein,the multifunctional flexible EHFs with e ective electro-/photo-thermal abilities are proposed by successive spraying Ag microparticles and MXene suspension between on waterborne polyurethane films,supplemented by a hot-pressing.The optimal coherent film exhibits a high electrical conductivity(1.17×10^(4)S m^(-1)),excellent Joule heating performance(121.3℃)at 2 V,and outstanding photo-thermal performance(66.2℃ within 70 s under 100 mW cm^(-1)).In addition,the EHFs-based single-electrode triboelectric nanogenerators(TENG)give short-circuit transferred charge of 38.9 nC,open circuit voltage of 114.7 V,and short circuit current of 0.82μA.More interestingly,the output voltage of TENG can be further increased via constructing the double triboelectrification layers.The comprehensive ability for harvesting various energies of the EHFs promises their potential to satisfy the corresponding requirements.展开更多
Flexible pressure sensors have attracted wide attention due to their applications to electronic skin,health monitoring,and human-machine interaction.However,the tradeoff between their high sensitivity and wide respons...Flexible pressure sensors have attracted wide attention due to their applications to electronic skin,health monitoring,and human-machine interaction.However,the tradeoff between their high sensitivity and wide response range remains a challenge.Inspired by human skin,we select commercial silicon carbide sandpaper as a template to fabricate carbon nanotube(CNT)/polydimethylsiloxane(PDMS)composite film with a hierarchical structured surface(h-CNT/PDMS)through solution blending and blade coating and then assemble the h-CNT/PDMS composite film with interdigitated electrodes and polyurethane(PU)scotch tape to obtain an h-CNT/PDMS-based flexible pressure sensor.Based on in-situ optical images and finite element analysis,the significant compressive contact effect between the hierarchical structured surface of h-CNT/PDMS and the interdigitated electrode leads to enhanced pressure sensitivity and a wider response range(0.1661 kPa^(-1),0.4574 kPa^(-1)and 0.0989 kPa^(-1)in the pressure range of 0–18 kPa,18–133 kPa and 133–300 kPa)compared with planar CNT/PDMS composite film(0.0066 kPa^(-1)in the pressure range of 0–240 kPa).The prepared pressure sensor displays rapid response/recovery time,excellent stability,durability,and stable response to different loading modes(bending and torsion).In addition,our pressure sensor can be utilized to accurately monitor and discriminate various stimuli ranging from human motions to pressure magnitude and spatial distribution.This study supplies important guidance for the fabrication of flexible pressure sensors with superior sensing performance in next-generation wearable electronic devices.展开更多
Aqueous zinc-ion batteries(ZIBs) are attracting considerable attention because of their low cost,high safety and abundant anode material resources.However,the major challenge faced by aqueous ZIBs is the lack of stabl...Aqueous zinc-ion batteries(ZIBs) are attracting considerable attention because of their low cost,high safety and abundant anode material resources.However,the major challenge faced by aqueous ZIBs is the lack of stable and high capacity cathode materials due to their complicated reaction mechanism and slow Zn-ion transport kinetics.This study reports a unique 3 D ’flower-like’ zinc cobaltite(ZnCo_(2)O_(4-x)) with enriched oxygen vacancies as a new cathode material for aqueous ZIBs.Computational calculations reveal that the presence of oxygen vacancies significantly enhances the electronic conductivity and accelerates Zn^(2+) diffusion by providing enlarged channels.The as-fabricated batteries present an impressive specific capacity of 148.3 mAh g^(-1) at the current density of 0.05 A g^(-1),high energy(2.8 Wh kg^(-1)) and power densities(27.2 W kg^(-1)) based on the whole device,which outperform most of the reported aqueous ZIBs.Moreover,a flexible solid-state pouch cell was demonstrated,which delivers an extremely stable capacity under bending states.This work demonstrates that the performance of Zn-ion storage can be effectively enhanced by tailoring the atomic structure of cathode materials,guiding the development of low-cost and eco-friendly energy storage materials.展开更多
The original version of this article unfortunately contained some mistakes.The corrections are updated as follows:Error 1:We found that Equations 3,4 and 6 were wrong in the published paper:Error 2:In the page 7,“Sin...The original version of this article unfortunately contained some mistakes.The corrections are updated as follows:Error 1:We found that Equations 3,4 and 6 were wrong in the published paper:Error 2:In the page 7,“Since N Ni/MXene-MF possessed numer-ous heterogeneous interfaces and abundant functional groups,the dielectric loss mechanism was explored.”展开更多
A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetrae...A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination;the MXene@c-MWCNT_(x:y)films are prepared by vacuum filtration tech-nology.In particular,the SNM and MXene@c-MWCNT_(6:4)as one unit layer(SMC_(1))are bonded together with 5 wt%polyvinyl alcohol(PVA)solution,which exhibits low thermal conductivity(0.066 W m^(-1)K^(-1))and good electromagnetic interference(EMI)shielding performance(average EMI SE_(T),37.8 dB).With the increase in func-tional unit layer,the overall thermal insulation performance of the whole composite film(SMC_(x))remains stable,and EMI shielding performance is greatly improved,especially for SMC_(3)with three unit layers,the average EMI SET is as high as 55.4 dB.In addition,the organic combination of rigid SNM and tough MXene@c-MWCNT_(6:4)makes SMC_(x)exhibit good mechanical tensile strength.Importantly,SMC_(x)exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment.Therefore,this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.展开更多
Alzheimer’s disease(AD)is a progressive and fatal neurodegenerative condition and the most prevalent cause of dementia.This disease is characterized by progressive cognitive impairment.The prevalence of AD is current...Alzheimer’s disease(AD)is a progressive and fatal neurodegenerative condition and the most prevalent cause of dementia.This disease is characterized by progressive cognitive impairment.The prevalence of AD is currently affecting more than 35 million people and is rising worldwide.No efficient therapy is currently available due to low drug potency and a number of various obstacles to delivery.Recent nanotechnological advancements have the potential to offer promising therapeutic options.Progress on nanomaterials as well as their applications in biomedicine is receiving increasing attention,especially the advantages of nanomaterial-based drug delivery systems.The aim of this review is to comprehensively summarize the latest developments in nanomaterial-based strategies for AD treatment,including nanoparticles,liposomes and other options for the delivery of therapeutic compounds and scaffolds for cell delivery strategies.Future research directions are also proposed.We hope this review can provide important information to guide the future development of nanomaterials in AD treatment.展开更多
Poly(vinyl alcohol)(PVA)/reduced graphene oxide(rGO)nanocomposites is prepared by the immersion of PVA/graphene oxide(GO)nanocomposites in the reducing agent aqueous solution.The PVA/graphene nanocomposites can be use...Poly(vinyl alcohol)(PVA)/reduced graphene oxide(rGO)nanocomposites is prepared by the immersion of PVA/graphene oxide(GO)nanocomposites in the reducing agent aqueous solution.The PVA/graphene nanocomposites can be used as scaffold after treatment by chemical crosslinking agents.The surface hydrophilicity of the nanocomposite scaffolds decreased with the addition of GO or rGO by measuring the contact angles of scaffolds.The electrical conductivity of PVA/rGO nanocomposite scaffold increased with rGO content increased.The highest conductivity of PVA/rGO nanocomposite scaffolds with 10 wt%rGO could reach to 12.16×10^(−3)S/m.The NIH-3T3 fibroblasts attach and grow well on the surface of PVA/rGO nanocomposite scaffolds with increasing the content of rGO.The number of cells obviously increases on the PVA/rGO nanocomposite scaffolds,especially,at 5 wt%and 10 wt%rGO.Furthermore,a good level of conductivity and a variation in the surface property of the PVA/rGO nanocomposite scaffolds have affected NIH-3T3 fibroblasts grow.展开更多
To address the ever-increasing CO_(2)concentration problem in the atmospheric air arisen by massive consumption of fossil fuels,electrocatalytic technologies that reduce CO_(2)to generate high value-added products hav...To address the ever-increasing CO_(2)concentration problem in the atmospheric air arisen by massive consumption of fossil fuels,electrocatalytic technologies that reduce CO_(2)to generate high value-added products have been gaining increasing interest.Cu-based CO_(2)reduction catalysts have attracted widespread attention owing to their capability of generating C1 and C_(2+)products.However,Cu-based catalysts are highly challenged by their low product selectivity.Recently,Cu-based bimetallic catalysts have been found the unique catalytical activity and selectivity in CO_(2)reduction reactions(CO_(2)RR).The incorporation of other metals can change the electronic circumstance of Cu-based catalysts,promoting the adsorption ability of the intermediate products and consequently leading to high selectivity.In this minireview,we intend to summarize recent advances of Cu-based bimetallic catalysts in producing C1 and C_(2+)products,involving designing heterostructure,alloy,defects and surface modification engineering.We pay special attention to the regulation of electronic structure of the composite catalysts,as well as insights into the relationship between electronic property and catalytical performance for Cu-based bimetallic catalysts.展开更多
基金support for this work by Key Research and Development Project of Henan Province(Grant.No.241111232300)the National Natural Science Foundation of China(Grant.No.52273085 and 52303113)the Open Fund of Yaoshan Laboratory(Grant.No.2024003).
文摘The morphological distribution of absorbent in composites is equally important with absorbents for the overall electromagnetic properties,but it is often ignored.Herein,a comprehensive consideration including electromagnetic component regulation,layered arrangement structure,and gradient concentration distribution was used to optimize impedance matching and enhance electromagnetic loss.On the microscale,the incorporation of magnetic Ni nanoparticles into MXene nanosheets(Ni@MXene)endows suitable intrinsic permittivity and permeability.On the macroscale,the layered arrangement of Ni@MXene increases the effective interaction area with electromagnetic waves,inducing multiple reflection/scattering effects.On this basis,according to the analysis of absorption,reflection,and transmission(A-R-T)power coefficients of layered composites,the gradient concentration distribution was constructed to realize the impedance matching at low-concentration surface layer,electromagnetic loss at middle concentration interlayer and microwave reflection at high-concentration bottom layer.Consequently,the layered gradient composite(LG5-10-15)achieves complete absorption coverage of X-band at thickness of 2.00-2.20 mm with RL_(min) of-68.67 dB at 9.85 GHz in 2.05 mm,which is 199.0%,12.6%,and 50.6%higher than non-layered,layered and layered descending gradient composites,respectively.Therefore,this work confirms the importance of layered gradient structure in improving absorption performance and broadens the design of high-performance microwave absorption materials.
基金supported by the National Natural Science Foundation of China(Nos.52373093 and 12072325)the Outstanding Youth Fund of Henan Province(No.242300421062)+1 种基金National Key R&D Program of China(No.2019YFA0706802)the 111 project(No.D18023).
文摘With the rapid development of wearable electronic skin technology, flexible strain sensors have shown great application prospects in the fields of human motion and physiological signal detection, medical diagnostics, and human-computer interaction owing to their outstanding sensing performance. This paper reports a strain sensor with synergistic conductive network, consisting of stable carbon nanotube dispersion (CNT) layer and brittle MXene layer by dip-coating and electrostatic self-assembly method, and breathable three-dimensional (3D) flexible substrate of thermoplastic polyurethane (TPU) fibrous membrane prepared through electrospinning technology. The MXene/CNT@PDA-TPU (MC@p-TPU) flexible strain sensor had excellent air permeability, wide operating range (0–450 %), high sensitivity (Gauge Factor, GFmax = 8089.7), ultra-low detection limit (0.05 %), rapid response and recovery times (40 ms/60 ms), and excellent cycle stability and durability (10,000 cycles). Given its superior strain sensing capabilities, this sensor can be applied in physiological signals detection, human motion pattern recognition, and driving exoskeleton robots. In addition, MC@p-TPU fibrous membrane also exhibited excellent photothermal conversion performance and can be used as a wearable photo-heater, which has far-reaching application potential in the photothermal therapy of human joint diseases.
基金financially supported by the Natural Science Foundation of Henan(242300421010)National Natural Science Foundation of China(52403055).
文摘As living standards improve,the energy consumption for regulating indoor temperature keeps increasing.Windows,in particular,enhance indoor brightness but also lead to increased energy loss,especially in sunny weather.Developing a product that can maintain indoor brightness while reducing energy consumption is a challenge.We developed a facile,spectrally selective transparent ultrahigh-molecular-weight polyethylene composite film to address this trade-off.It is based on a blend of antimony-doped tin oxide and then spin-coated hydrophobic fumed silica,achieving a high visible light transmittance(>70%)and high shielding rates for ultraviolet(>90%)and near-infrared(>70%).When applied to the acrylic window of containers and placed outside,this film can cause a 10℃ temperature drop compared to a pure polymer film.Moreover,in building energy simulations,the annual energy savings could be between 14.1%~31.9%per year.The development of energy-efficient and eco-friendly transparent films is crucial for reducing energy consumption and promoting sustainability in the window environment.
基金supported by the Key Research and Development Project of Henan Province of China(No.241111232300)the National Natural Science Foundation of China(Nos.52303113 and 5227308)the Open Project Program of Yaoshan Laboratory(No.2024003).
文摘Two-dimensional transition metal carbon/nitrides(MXenes)have emerged as prominent materials in the development of high-performance electromagnetic interference(EMI)shielding films owing to their ex-ceptional electrical conductivity,special layered structure,and chemically active surfaces.Substantial ef-forts have been devoted to addressing the poor mechanical strength and limited functionality of pure MXene films through structural design and interfacial reinforcement.However,there is a notable lack of a systematic review of the research on MXene-based EMI shielding films with multi-layer structures,which could provide a theoretical foundation and technical guidance for the development and application of shielding films.This review aims to summarize the recent advancements in MXene-based layered films for EMI shielding.First,the structure and properties of MXene nanosheets are systematically introduced.Next,the optimization of layered structures and interfacial reinforcement strategies in MXene-based EMI shielding films are objectively reviewed,followed by a discussion of their multifunctional compatibility.Finally,future prospects and challenges for MXene-based layered EMI shielding films are highlighted.
基金the National Natural Science Foundation of China(No.5220031085)the Postdoctoral Research Project in Henan Province(No.HN2022054)+2 种基金the Key Scientific Research Projects of Colleges and Universities in Henan Province(No.23A430009)the State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-4-03)the Key Technologies R&D Program of Henan Province(No.242102230131)。
文摘The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials.However,the pursuit of sustained antibacterial efficacy remains a formidable challenge.In this context,we proposed a novel strategy that leverages swelling and erosion mechanisms to facilitate drug release of drug-loaded ultrahigh molecular weight polyethylene(UHMWPE),thereby ensuring its long-lasting antibacterial performance.Polyethylene oxide(PEO),a hydrophilic polymer with fast hydrating ability and high swelling capacity,was incorporated in UHMWPE alongside the antibacterial tea polyphenol(epigallocatechin gallate,EGCG as representative).The swelling of PEO enhanced water infiltration into the matrix,while the erosion of PEO balanced the release of the encapsulated EGCG,resulting in a steady release.The behavior was supported by the EGCG release profiles and the corresponding fitted release kinetic models.As demonstrated by segmented antibacterial assessments,the antibacterial efficiency was enhanced 2to 3 times in the PEO/EGCG/UHMWPE composite compared to that of EGCG/UHMWPE.Additionally,the PEO/EGCG/UHMWPE composite exhibited favorable biocompatibility and mechanical performance,making it a potential candidate for the development of drug-releasing joint implants to combat prosthetic bacterial infections.
文摘The service life and properties of Carbon fiber reinforced polycarbonate (CF/PC) composites are seriously affected by ultraviolet radiation from outdoor exposure during aging. In this work, the changes of structure and solid particle erosion resistance for CF/PC composites after ultraviolet irradiation were studied. It was shown that ultraviolet irradiation causes photo-oxygen aging and photo-fries re-arrangement of the composite, and the result was confirmed by FTIR. We correlated the solid particle erosion resistance with aging time, and found that the solid particle erosion resistance of CF/PC composites greatly decreased by UVB irradiation during 15 hours. Furthermore, the eroded material surface was analyzed using scanning electron microscope (SEM). It suggests that ultraviolet aging leads to plasticization and degradation, resulting in reduction of erosion resistance of the composite.
基金The authors thank National Natural Science Foundation of China(51803190)National Key R&D Program of China(2019YFA0706802)financial support.
文摘The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot.Here,the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of melamine foam(MF)through electrostatic self-assembly and dip-coating adsorption process,realizing the integration of microwave absorption,infrared stealth,and flame retardant.Remarkably,the Ni/MXene-MF achieves a minimum reflection loss(RLmin)of−62.7 dB with a corresponding effective absorption bandwidth(EAB)of 6.24 GHz at 2 mm and an EAB of 6.88 GHz at 1.8 mm.Strong electromagnetic wave absorption is attributed to the three-dimensional magnetic/conductive networks,which provided excellent impedance matching,dielectric loss,magnetic loss,interface polarization,and multiple attenuations.In addition,the Ni/MXene-MF endows low density,excellent heat insulation,infrared stealth,and flame-retardant functions.This work provided a new development strategy for the design of multifunctional and efficient electromagnetic wave absorbing materials.
基金financial support from National Natural Science Foundation of China(21704096,51703217)the China Postdoctoral Science Foundation(Grant No.2019M662526)financial support from Taif University Researchers Supporting Project Number(TURSP-2020/135),Taif University,Taif,Saudi Arabia。
文摘With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel(CA) with highly enhanced thermal conductivity(TC) in vertical planes was successfully obtained by constructing a vertically aligned silicon carbide nanowires(SiC NWs)/boron nitride(BN) network via the ice template-assisted strategy. The unique network structure of SiC NWs connected to BN ensures that the TC of the composite in the vertical direction reaches 2.21 W m^(-1) K^(-1) at a low hybrid filler loading of 16.69 wt%, which was increased by 890% compared to pure epoxy(EP). In addition, relying on unique porous network structure of CA, EP-based composite also showed higher TC than other comparative samples in the horizontal direction. Meanwhile, the composite exhibits good electrically insulating with a volume electrical resistivity about 2.35 × 10^(11) Ω cm and displays excellent electromagnetic wave absorption performance with a minimum reflection loss of-21.5 dB and a wide effective absorption bandwidth(<-10 dB) from 8.8 to 11.6 GHz. Therefore, this work provides a new strategy for manufacturing polymer-based composites with excellent multifunctional performances in microelectronic packaging applications.
基金supported by the Australian Research Council(ARC)through the Discovery Project(DP180102297)the Future Fellow Project(FT180100705)+2 种基金the support from the Open Project of State Key Laboratory of Advanced Special Steelthe Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS 2021-**)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200,20511107700)。
文摘Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost catalysts for OER process is essential as the conventional catalysts still rely on precious metals.Transition metal-based compounds have been widely investigated as active OER catalysts,and renewed interest in the high valence metals engineered compounds has been achieved for superior catalytic activity and stability.However,an in-depth understanding of the construction strategies and induced effects for the high valence metals engineered catalysts is still lacking and desired.In this review,we have summarized the construction strategies of high valence metals as dopants or formed heterostructures with the iron/cobalt/nickel(Fe/Co/Ni)-based catalysts.Then the induced effects on Fe/Co/Ni-based catalysts by incorporating high valence metals,e.g.,accelerating the surface reconstruction,forming amorphous structure,generating vacancies/defects,and acting as stabilizers,are highlighted.The impacts of high valence metals on OER performance are elucidated based on different elements,including molybdenum(Mo),tungsten(W),cerium(Ce),vanadium(V),chromium(Cr),manganese(Mn),niobium(Nb),zirconium(Zr).The correlations of construction strategies,induced effects,catalytic activity and OER reaction pathways are elaborated.Finally,the remaining challenges for further enhancements of OER performance induced by high valence metals are presented.
基金National Natural Science Foundation of China(Nos.51803190,11432003,11572290)National Key Research and Development Program of China(No.2016YFB0101602)+2 种基金China Postdoctoral Science Foundation(Nos.2018M642779,2019M652573,2019T120643)International Postdoctoral Exchange Fellowship Program,University Key Research Project of Henan Province(No.18A430031)Guangdong Province Pearl River Scholar Funded Scheme(2016)for financial support。
文摘Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,there is still a lack of a green and facile way to prepare PLA oil-water separation materials.In this work,a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported.The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight.In addition,it could also be applicated as a filter with excellent efficiency(50.9 m^3 m^(-2) h^(-1)).
基金financially supported by the National Key R&D Program of China(No.2019YFA0706802)the National Natural Science Foundation of China(Nos.51903223 and 12072325)the Key Technologies R&D Program of Henan Province(No.212102210302)。
文摘With the discovery of the two-dimensional(2D) MXene, it shows a great application potential in the field of electromagnetic interference(EMI) shielding, but the mechanical brittleness and easy oxidation of MXene limit its wide application. For this reason, a double crosslinking strategy is provided to solve the above problems in a nacre-like “brick-mortar” layered MXene/cellulose nanofiber(MXene/CNF) film.Typically, the film was firstly suffered by dopamine modification, then was further reinforced by secondary Ca^(2+)bridging, so as to obtain excellent mechanical properties and antioxidative EMI shielding performance. Comparing with the single crosslinking, the double crosslinking strategy reveals a higher efficiency in improving the mechanical property. The mechanical strength and toughness of the double crosslinking MXene/CNF film can increase to 142.2 MPa and 9.48 MJ/m^(3), respectively. More importantly, while achieving good mechanical properties, the MXene composite film still holds a very stable EMI shielding performance of more than 44.6 dB when suffering from the oxidation treatment of hightemperature annealing, showing excellent anti-oxidation ability and environment tolerance. Therefore,this work provides a universal but effective double crosslinking strategy to solve the mechanical brittleness and easy oxidation of MXene-based composites, thus showing a huge potential in flexible EMI shielding applications.
基金National Natural Science Foundation of China(51803190)National Key R&D Program of China(2019YFA0706802)for financial support。
文摘Ultra-thin flexible films have attracted wide attention because of their excellent ductility and potential versatility.In particular,the energy-harvesting films(EHFs)have become a research hotspot because of the indispensability of power source in various devices.However,the design and fabrication of such films that can capture or transform di erent types of energy from environments for multiple usages remains a challenge.Herein,the multifunctional flexible EHFs with e ective electro-/photo-thermal abilities are proposed by successive spraying Ag microparticles and MXene suspension between on waterborne polyurethane films,supplemented by a hot-pressing.The optimal coherent film exhibits a high electrical conductivity(1.17×10^(4)S m^(-1)),excellent Joule heating performance(121.3℃)at 2 V,and outstanding photo-thermal performance(66.2℃ within 70 s under 100 mW cm^(-1)).In addition,the EHFs-based single-electrode triboelectric nanogenerators(TENG)give short-circuit transferred charge of 38.9 nC,open circuit voltage of 114.7 V,and short circuit current of 0.82μA.More interestingly,the output voltage of TENG can be further increased via constructing the double triboelectrification layers.The comprehensive ability for harvesting various energies of the EHFs promises their potential to satisfy the corresponding requirements.
基金supported by the National Natural Science Foundation of China(NO:51803191,12072325,52103100)the National Key R&D Program of China(2019YFA0706802)+1 种基金the 111 project(D18023)the Key Scientific and Technological Project of Henan Province(202102210038).
文摘Flexible pressure sensors have attracted wide attention due to their applications to electronic skin,health monitoring,and human-machine interaction.However,the tradeoff between their high sensitivity and wide response range remains a challenge.Inspired by human skin,we select commercial silicon carbide sandpaper as a template to fabricate carbon nanotube(CNT)/polydimethylsiloxane(PDMS)composite film with a hierarchical structured surface(h-CNT/PDMS)through solution blending and blade coating and then assemble the h-CNT/PDMS composite film with interdigitated electrodes and polyurethane(PU)scotch tape to obtain an h-CNT/PDMS-based flexible pressure sensor.Based on in-situ optical images and finite element analysis,the significant compressive contact effect between the hierarchical structured surface of h-CNT/PDMS and the interdigitated electrode leads to enhanced pressure sensitivity and a wider response range(0.1661 kPa^(-1),0.4574 kPa^(-1)and 0.0989 kPa^(-1)in the pressure range of 0–18 kPa,18–133 kPa and 133–300 kPa)compared with planar CNT/PDMS composite film(0.0066 kPa^(-1)in the pressure range of 0–240 kPa).The prepared pressure sensor displays rapid response/recovery time,excellent stability,durability,and stable response to different loading modes(bending and torsion).In addition,our pressure sensor can be utilized to accurately monitor and discriminate various stimuli ranging from human motions to pressure magnitude and spatial distribution.This study supplies important guidance for the fabrication of flexible pressure sensors with superior sensing performance in next-generation wearable electronic devices.
基金supported by the National Natural Science Foundation of China(Nos.51873198,51503184 and 21703248)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB20000000)+1 种基金the Engineering and Physical Sciences Research Council(EPSRC,EP/R023581/1)the RSC Mobility Grant(M19-7656)and the STFC Batteries Network(ST/R006873/1)。
文摘Aqueous zinc-ion batteries(ZIBs) are attracting considerable attention because of their low cost,high safety and abundant anode material resources.However,the major challenge faced by aqueous ZIBs is the lack of stable and high capacity cathode materials due to their complicated reaction mechanism and slow Zn-ion transport kinetics.This study reports a unique 3 D ’flower-like’ zinc cobaltite(ZnCo_(2)O_(4-x)) with enriched oxygen vacancies as a new cathode material for aqueous ZIBs.Computational calculations reveal that the presence of oxygen vacancies significantly enhances the electronic conductivity and accelerates Zn^(2+) diffusion by providing enlarged channels.The as-fabricated batteries present an impressive specific capacity of 148.3 mAh g^(-1) at the current density of 0.05 A g^(-1),high energy(2.8 Wh kg^(-1)) and power densities(27.2 W kg^(-1)) based on the whole device,which outperform most of the reported aqueous ZIBs.Moreover,a flexible solid-state pouch cell was demonstrated,which delivers an extremely stable capacity under bending states.This work demonstrates that the performance of Zn-ion storage can be effectively enhanced by tailoring the atomic structure of cathode materials,guiding the development of low-cost and eco-friendly energy storage materials.
文摘The original version of this article unfortunately contained some mistakes.The corrections are updated as follows:Error 1:We found that Equations 3,4 and 6 were wrong in the published paper:Error 2:In the page 7,“Since N Ni/MXene-MF possessed numer-ous heterogeneous interfaces and abundant functional groups,the dielectric loss mechanism was explored.”
基金the China Scholarship Council(2021)the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-249-03”.
文摘A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination;the MXene@c-MWCNT_(x:y)films are prepared by vacuum filtration tech-nology.In particular,the SNM and MXene@c-MWCNT_(6:4)as one unit layer(SMC_(1))are bonded together with 5 wt%polyvinyl alcohol(PVA)solution,which exhibits low thermal conductivity(0.066 W m^(-1)K^(-1))and good electromagnetic interference(EMI)shielding performance(average EMI SE_(T),37.8 dB).With the increase in func-tional unit layer,the overall thermal insulation performance of the whole composite film(SMC_(x))remains stable,and EMI shielding performance is greatly improved,especially for SMC_(3)with three unit layers,the average EMI SET is as high as 55.4 dB.In addition,the organic combination of rigid SNM and tough MXene@c-MWCNT_(6:4)makes SMC_(x)exhibit good mechanical tensile strength.Importantly,SMC_(x)exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment.Therefore,this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.
基金financially supported by Hunan Provincial Key Laboratory of Micro&Nano Materials Interface Sciencethe National Natural Science Foundation of China(Nos.81603670,81873169,21773311,21972169)+1 种基金Hunan Provincial Natural Science Foundation of China(Nos.2017JJ3459,2020JJ4803)the Hunan Provincial Science and Technology Plan Project,China(No.2019TP1001)。
文摘Alzheimer’s disease(AD)is a progressive and fatal neurodegenerative condition and the most prevalent cause of dementia.This disease is characterized by progressive cognitive impairment.The prevalence of AD is currently affecting more than 35 million people and is rising worldwide.No efficient therapy is currently available due to low drug potency and a number of various obstacles to delivery.Recent nanotechnological advancements have the potential to offer promising therapeutic options.Progress on nanomaterials as well as their applications in biomedicine is receiving increasing attention,especially the advantages of nanomaterial-based drug delivery systems.The aim of this review is to comprehensively summarize the latest developments in nanomaterial-based strategies for AD treatment,including nanoparticles,liposomes and other options for the delivery of therapeutic compounds and scaffolds for cell delivery strategies.Future research directions are also proposed.We hope this review can provide important information to guide the future development of nanomaterials in AD treatment.
基金financially supported by the Wisconsin Institute for Discovery(WID)at the University of Wisconsin-Madison and the China Scholarship Council.
文摘Poly(vinyl alcohol)(PVA)/reduced graphene oxide(rGO)nanocomposites is prepared by the immersion of PVA/graphene oxide(GO)nanocomposites in the reducing agent aqueous solution.The PVA/graphene nanocomposites can be used as scaffold after treatment by chemical crosslinking agents.The surface hydrophilicity of the nanocomposite scaffolds decreased with the addition of GO or rGO by measuring the contact angles of scaffolds.The electrical conductivity of PVA/rGO nanocomposite scaffold increased with rGO content increased.The highest conductivity of PVA/rGO nanocomposite scaffolds with 10 wt%rGO could reach to 12.16×10^(−3)S/m.The NIH-3T3 fibroblasts attach and grow well on the surface of PVA/rGO nanocomposite scaffolds with increasing the content of rGO.The number of cells obviously increases on the PVA/rGO nanocomposite scaffolds,especially,at 5 wt%and 10 wt%rGO.Furthermore,a good level of conductivity and a variation in the surface property of the PVA/rGO nanocomposite scaffolds have affected NIH-3T3 fibroblasts grow.
基金supported by Hunan Provincial Key Laboratory of Micro&Nano Materials Interface Science,China,the National Natural Science Foundation of China(Nos.21773311,21972169)the Hunan Provincial Science and Technology Plan Project,China(No.2019TP1001)the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,China.
文摘To address the ever-increasing CO_(2)concentration problem in the atmospheric air arisen by massive consumption of fossil fuels,electrocatalytic technologies that reduce CO_(2)to generate high value-added products have been gaining increasing interest.Cu-based CO_(2)reduction catalysts have attracted widespread attention owing to their capability of generating C1 and C_(2+)products.However,Cu-based catalysts are highly challenged by their low product selectivity.Recently,Cu-based bimetallic catalysts have been found the unique catalytical activity and selectivity in CO_(2)reduction reactions(CO_(2)RR).The incorporation of other metals can change the electronic circumstance of Cu-based catalysts,promoting the adsorption ability of the intermediate products and consequently leading to high selectivity.In this minireview,we intend to summarize recent advances of Cu-based bimetallic catalysts in producing C1 and C_(2+)products,involving designing heterostructure,alloy,defects and surface modification engineering.We pay special attention to the regulation of electronic structure of the composite catalysts,as well as insights into the relationship between electronic property and catalytical performance for Cu-based bimetallic catalysts.
