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
In this study,the hydrogel network was reinforced by covalent-like hydrogen bonding,and the strong binding ability of boron-nitrogen coordination served as the main driving force.Among them,acrylamide(AM)and 3-acrylam...In this study,the hydrogel network was reinforced by covalent-like hydrogen bonding,and the strong binding ability of boron-nitrogen coordination served as the main driving force.Among them,acrylamide(AM)and 3-acrylamidophenylboronic acid(AAPBA)were the main body,and the numerous hydroxyl groups in the trehalose(Treh)molecule and other polymer groups formed strong hydrogen bonding interactions to improve the mechanical properties of the PAM/PAAPBA/Treh(PAAT)hydrogel and ensured the simplicity of the synthesis process.The hydrogel possessed high strain at break(1239%),stress(64.7 kPa),low hysteresis(100%to 500%strain,corresponding to dissipation energy from 1.37 to 7.80 kJ/m^(3)),and outstanding cycling stability(retained more than 90%of maximum stress after 200 ten-sile cycles).By integrating carbon nanotubes(CNTs)into PAAT hydrogel(PAATC),the PAATC hydrogel with excellent strain response performance was successfully constructed.The PAATC conductive hydro-gel exhibited high sensitivity(gauge factor(GF)=10.58 and sensitivity(S)=0.304 kPa^(-1)),wide strain response range(0.5%-1000%),fast response time(450 ms),and short recovery time(350 ms),excellent fatigue resistance,and strain response stability.Furthermore,the PAATC-based triboelectric nanogener-ator(TENG)displayed outstanding energy harvesting performance,which shows its potential for appli-cation in self-powered electronic devices.展开更多
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
Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power density.In the last decade,carbon and carbonaceous materials,conducting po...Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power density.In the last decade,carbon and carbonaceous materials,conducting polymers and transition metal oxide/hydroxide based electrode materials have been made to show a remarkable electrochemical performance.Rare-earth materials have attracted significant research attention as an electrode material for supercapacitor applications based on their physicochemical properties.In this review,rare earth metals,rare earth metal oxides/hydroxides,rare-earth metal chalcogenides,rare-earth metal/carbon composites and rare-earth metal/metal oxide composites based electrode materials are discussed for supercapacitors.We also discuss the energy chemistry of rare-earth metal-based materials.Besides the factors that affect the performance of the electrode materials,their evaluation methods and supercapacitor performances are discussed in details.Finally,the future outlook in rare-earth-based electrode materials is revealed towards its current developments for supercapacitor applications.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
Thin films of perovskite deposited from solution inevitably introduce large number of defects,which serve as recombination centers and are detrimental for solar cell performance.Although many small molecules and polym...Thin films of perovskite deposited from solution inevitably introduce large number of defects,which serve as recombination centers and are detrimental for solar cell performance.Although many small molecules and polymers have been delicately designed to migrate defects of perovskite films,exploiting credible passivation agents based on natural materials would offer an alternative approach.Here,an ecofriendly and cost-effective biomaterial,ploy-L-lysine(PLL),is identified to effectively passivate the defects of perovskite films prepared by blade-coating.It is found that incorporation of a small amount(2.5 mg mL^(-1))of PLL significantly boosts the performance of printed devices,yielding a high efficiency of 19.45% with an increase in open-circuit voltage by up to 100 mV.Density functional theory calculations combined with X-ray photoelectron spectroscopy reveal that the functional groups(-NH2,-COOH)of PLL effectively migrate the Pb-I antisite defects via Pb-N coordination and suppress the formation of metallic Pb in the blade-coated perovskite film.This work suggests a viable avenue to exploit passivation agents from natural materials for preparation of high-quality perovskite layers for optoelectronic applications.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
Herein, the authors review the self-regulation system secured by well-designed hybrid materials, composites, and complex system. As a broad concept, the self-regulated material/system has been defined in a wide resear...Herein, the authors review the self-regulation system secured by well-designed hybrid materials, composites, and complex system. As a broad concept, the self-regulated material/system has been defined in a wide research field and proven to be of great interest for use in a biomedical system, mechanical system, physical system, as the fact of something such as an organisation regulating itself without intervention from external perturbation. Here, they focus on the most recent discoveries of self-regulation phenomenon and progress in utilising the self-regulation design. This paper concludes by examining various practical applications of the remarkable materials and systems including manipulation of the oil/water interface, cell out-layer structure, radical activity, electron energy level, and mechanical structure of nanomaterials. From material science to bioengineering, self-regulation proves to be not only viable, but increasingly useful in many applications. As part of intelligent engineering, self-regulatory materials are expected to be more used as integrated intelligent components.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
A non-isothermal injection molding process for a non-Newtonian viscous pseudoplastic fluid is simulated.A conservative interface capturing technique and the flow field solving method are coupled to perform a dynamic s...A non-isothermal injection molding process for a non-Newtonian viscous pseudoplastic fluid is simulated.A conservative interface capturing technique and the flow field solving method are coupled to perform a dynamic simulation.The validity of the numerical method is verified by a benchmark problem.The melt interface evolution versus time is captured and the physical quantities such as temperature,velocity and pressure at each time step are obtained with corresponding analysis.A"frozen skin"layer with the thickness increasing versus time during the injection process is found.The fact that the"frozen skin"layer can be reduced by increasing the injection velocity is numerically verified.The fountain flow phenomenon near the melt interface is also captured.Moreover,comparisons with the non-isothermal Newtonian case show that the curvatures of the interface arcs and the pressure contours near the horizontal mid-line of the cavity for the non-Newtonian pseudoplastic case is larger than that for the Newtonian case.The velocity profiles are different at different positions for the non-Newtonian pseudoplastic case,while in the case of Newtonian flow the velocity profiles are parabolic and almost the same at different positions.展开更多
The controllable construction of two-dimensional(2D)metal–organic framework(MOF)nanosheets with favorable electrochemical performances is greatly challenging for energy storage.Here,we design an in situ induced growt...The controllable construction of two-dimensional(2D)metal–organic framework(MOF)nanosheets with favorable electrochemical performances is greatly challenging for energy storage.Here,we design an in situ induced growth strategy to construct the ultrathin carboxylated carbon nanotubes(C-CNTs)interpenetrated nickel MOF(Ni-MOF/C-CNTs)nanosheets.The deliberate thickness and specific surface area of novel 2D hybrid nanosheets can be effectively tuned via finely controlling C-CNTs involvement.Due to the unique microstructure,the integrated 2D hybrid nanosheets are endowed with plentiful electroactive sites to promote the electrochemical performances greatly.The prepared Ni-MOF/C-CNTs nanosheets exhibit superior specific capacity of 680 C g^−1 at 1 A g^−1 and good capacity retention.The assembled hybrid device demonstrated the maximum energy density of 44.4 Wh kg^−1 at a power density of 440 W kg^−1.Our novel strategy to construct ultrathin 2D MOF with unique properties can be extended to synthesize various MOF-based functional materials for diverse 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
Designing a durable lithium metal anode for solid state batteries requires a controllable and uniform deposition of lithium, and the metal lithium layer should maintain a good interface contact with solid state electr...Designing a durable lithium metal anode for solid state batteries requires a controllable and uniform deposition of lithium, and the metal lithium layer should maintain a good interface contact with solid state electrolyte during cycles. In this work, we construct a robust functional interface layer on the modified LiB electrode which considerably improves the electrochemical stability of lithium metal electrode in solid state batteries. It is found that the functional interface layer consisting of polydioxolane, polyiodide ion and Li TFSI effectively restrains the growth of lithium dendrites through the redox shuttle reaction of I-/I3-and maintains a good contact between lithium anode and solid electrolyte during cycles. Benefit from these two advantages, the modified Li-B anode exhibits a remarkable cyclic performance in comparison with those of the bare Li-B anode.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
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
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 improve the strength of carbon fiber(CF) reinforced Polycaprolactam(PA6) composites, controlled amounts of carbon nanotubes(CNTs) were grafted onto the surface of CF to prepare the hybrid reinforcement(HR). We used...To improve the strength of carbon fiber(CF) reinforced Polycaprolactam(PA6) composites, controlled amounts of carbon nanotubes(CNTs) were grafted onto the surface of CF to prepare the hybrid reinforcement(HR). We used HR to fabricate laminate and H-sample to test the interfacial bonding strength(IBS) of the composites by means of a novel process called three-dimensional printed molding(3 D-PM). By using the melt drop printing method, we measured the contact angles between PA6 and CF(without sizing) and between PA6 and HR. The IBS and the mechanical properties of the composites were obtained by the tensile test. The experimental result indicated that CF grafted by 0.25% weight fraction of CNT or more could develop a special microstructure similar to the micro-pits on the surface of CF, which improved the wettability of CF and PA6 due to the increased surface area and the roughness of CF. When the weight fraction of CNT reached 0.25%, the IBS increased by 41.8%, the tensile strength by 130%, and the interfacial shear strength(IFSS) by 238%. The interfacial dimple fracture was observed by Scanning Electron Microscope(SEM), which revealed that the composites were able to absorb more deforming energy before fracture. The modified surface microstructure of CF would prevent crack propagation at the interface and increase the mechanical properties of thermoplastic composites(TPCs).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
Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially acces...Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially accessible internal spaces,and so forth.Dissimilar guest species(such as organic groups or metal nanoparticles)could be readily decorated onto the interfaces of the channels and pores,realizing the functionalization of dendritic mesoporous silica nanoparticles for targeted applications.As adsorbents and catalysts,dendritic mesoporous silica nanoparticles-based materials have experienced nonignorable development in CO_(2)capture and catalytic conversion.This comprehensive review provides a critical survey on this pregnant subject,summarizing the designed construction of novel dendritic mesoporous silica nanoparticles-based materials,the involved chemical reactions(such as CO_(2)methanation,dry reforming of CH_(4)),the value-added chemicals from CO_(2)(such as cyclic carbonates,2-oxazolidinones,quinazoline-2,4(1H,3H)-diones),and so on.The adsorptive and catalytic performances have been compared with traditional silica mesoporous materials(such as SBA-15 or MCM-41),and the corresponding reaction mechanisms have been thoroughly revealed.It is sincerely expected that the in-depth discussion could give materials scientists certain inspiration to design brand-new dendritic mesoporous silica nanoparticles-based materials with superior capabilities towards CO_(2)capture,utilization,and storage.展开更多
The continuous miniaturization and high-power development of electronic devices have given rise to severe interface thermal issues,which urgently demand highly thermally conductive thermal interface materials(TIMs)to ...The continuous miniaturization and high-power development of electronic devices have given rise to severe interface thermal issues,which urgently demand highly thermally conductive thermal interface materials(TIMs)to eliminate excessive heat accumulation and ensure the normal operation of devices[1].展开更多
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the financial support from the National Natural Science Foundation of China (52002356)the China Postdoctoral Science Foundation (2020M672269)the National Key R&D program of China (2019YFA0706802)
文摘In this study,the hydrogel network was reinforced by covalent-like hydrogen bonding,and the strong binding ability of boron-nitrogen coordination served as the main driving force.Among them,acrylamide(AM)and 3-acrylamidophenylboronic acid(AAPBA)were the main body,and the numerous hydroxyl groups in the trehalose(Treh)molecule and other polymer groups formed strong hydrogen bonding interactions to improve the mechanical properties of the PAM/PAAPBA/Treh(PAAT)hydrogel and ensured the simplicity of the synthesis process.The hydrogel possessed high strain at break(1239%),stress(64.7 kPa),low hysteresis(100%to 500%strain,corresponding to dissipation energy from 1.37 to 7.80 kJ/m^(3)),and outstanding cycling stability(retained more than 90%of maximum stress after 200 ten-sile cycles).By integrating carbon nanotubes(CNTs)into PAAT hydrogel(PAATC),the PAATC hydrogel with excellent strain response performance was successfully constructed.The PAATC conductive hydro-gel exhibited high sensitivity(gauge factor(GF)=10.58 and sensitivity(S)=0.304 kPa^(-1)),wide strain response range(0.5%-1000%),fast response time(450 ms),and short recovery time(350 ms),excellent fatigue resistance,and strain response stability.Furthermore,the PAATC-based triboelectric nanogener-ator(TENG)displayed outstanding energy harvesting performance,which shows its potential for appli-cation in self-powered electronic devices.
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the funding for this project through the National Nature Science Foundations of China(Grant No.51873083)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2018-4-27)+1 种基金Key University Science Research Project of Jiangsu Province(18KJA130001)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX18_0759,SJCX19_0584)。
文摘Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power density.In the last decade,carbon and carbonaceous materials,conducting polymers and transition metal oxide/hydroxide based electrode materials have been made to show a remarkable electrochemical performance.Rare-earth materials have attracted significant research attention as an electrode material for supercapacitor applications based on their physicochemical properties.In this review,rare earth metals,rare earth metal oxides/hydroxides,rare-earth metal chalcogenides,rare-earth metal/carbon composites and rare-earth metal/metal oxide composites based electrode materials are discussed for supercapacitors.We also discuss the energy chemistry of rare-earth metal-based materials.Besides the factors that affect the performance of the electrode materials,their evaluation methods and supercapacitor performances are discussed in details.Finally,the future outlook in rare-earth-based electrode materials is revealed towards its current developments for supercapacitor applications.
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.
基金supported by the National Natural Science Foundation of China(Grant No.61705090,11804117)Natural Science Foundation of Guangdong Province(2020A1515010853)。
文摘Thin films of perovskite deposited from solution inevitably introduce large number of defects,which serve as recombination centers and are detrimental for solar cell performance.Although many small molecules and polymers have been delicately designed to migrate defects of perovskite films,exploiting credible passivation agents based on natural materials would offer an alternative approach.Here,an ecofriendly and cost-effective biomaterial,ploy-L-lysine(PLL),is identified to effectively passivate the defects of perovskite films prepared by blade-coating.It is found that incorporation of a small amount(2.5 mg mL^(-1))of PLL significantly boosts the performance of printed devices,yielding a high efficiency of 19.45% with an increase in open-circuit voltage by up to 100 mV.Density functional theory calculations combined with X-ray photoelectron spectroscopy reveal that the functional groups(-NH2,-COOH)of PLL effectively migrate the Pb-I antisite defects via Pb-N coordination and suppress the formation of metallic Pb in the blade-coated perovskite film.This work suggests a viable avenue to exploit passivation agents from natural materials for preparation of high-quality perovskite layers for optoelectronic applications.
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This publication was made possible by funding from the NIMHD-RCMI Grant no. 5G12MD007595, the National Institute of Minority Health, Health Disparities, and the NIGMS-BUILD Grant no. 8UL1GM118967, and the National Science Foundation （Grant no. 1700429）. This publication was also made possible by the Louisiana Cancer Research Consortium. The contents axe solely the responsibility of the authors and do not necessarily represent the official views of the NIMHD. The authors appreciate the support of Nanhu Scholars Program for Young Scholars of Xinyang Normal University and the Science and Technology Development Plan （No. J17KA006） from Shandong Provincial Education Department as well. Z.H., K.L and D.H. axe equally contributed to this work.
文摘Herein, the authors review the self-regulation system secured by well-designed hybrid materials, composites, and complex system. As a broad concept, the self-regulated material/system has been defined in a wide research field and proven to be of great interest for use in a biomedical system, mechanical system, physical system, as the fact of something such as an organisation regulating itself without intervention from external perturbation. Here, they focus on the most recent discoveries of self-regulation phenomenon and progress in utilising the self-regulation design. This paper concludes by examining various practical applications of the remarkable materials and systems including manipulation of the oil/water interface, cell out-layer structure, radical activity, electron energy level, and mechanical structure of nanomaterials. From material science to bioengineering, self-regulation proves to be not only viable, but increasingly useful in many applications. As part of intelligent engineering, self-regulatory materials are expected to be more used as integrated intelligent components.
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Supported by the National Natural Science Foundation of China（10871159） the National Basic Research Program of China（2005CB321704）
文摘A non-isothermal injection molding process for a non-Newtonian viscous pseudoplastic fluid is simulated.A conservative interface capturing technique and the flow field solving method are coupled to perform a dynamic simulation.The validity of the numerical method is verified by a benchmark problem.The melt interface evolution versus time is captured and the physical quantities such as temperature,velocity and pressure at each time step are obtained with corresponding analysis.A"frozen skin"layer with the thickness increasing versus time during the injection process is found.The fact that the"frozen skin"layer can be reduced by increasing the injection velocity is numerically verified.The fountain flow phenomenon near the melt interface is also captured.Moreover,comparisons with the non-isothermal Newtonian case show that the curvatures of the interface arcs and the pressure contours near the horizontal mid-line of the cavity for the non-Newtonian pseudoplastic case is larger than that for the Newtonian case.The velocity profiles are different at different positions for the non-Newtonian pseudoplastic case,while in the case of Newtonian flow the velocity profiles are parabolic and almost the same at different positions.
基金supported by National Natural Science Foundation of China(21878062)
文摘The controllable construction of two-dimensional(2D)metal–organic framework(MOF)nanosheets with favorable electrochemical performances is greatly challenging for energy storage.Here,we design an in situ induced growth strategy to construct the ultrathin carboxylated carbon nanotubes(C-CNTs)interpenetrated nickel MOF(Ni-MOF/C-CNTs)nanosheets.The deliberate thickness and specific surface area of novel 2D hybrid nanosheets can be effectively tuned via finely controlling C-CNTs involvement.Due to the unique microstructure,the integrated 2D hybrid nanosheets are endowed with plentiful electroactive sites to promote the electrochemical performances greatly.The prepared Ni-MOF/C-CNTs nanosheets exhibit superior specific capacity of 680 C g^−1 at 1 A g^−1 and good capacity retention.The assembled hybrid device demonstrated the maximum energy density of 44.4 Wh kg^−1 at a power density of 440 W kg^−1.Our novel strategy to construct ultrathin 2D MOF with unique properties can be extended to synthesize various MOF-based functional materials for diverse 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. 21805113)the Fundamental Research Funds for the Central Universities (NO. 11618410 and NO. 11619103)the China Postdoctoral Science Foundation (NO. 2019M653271)。
文摘Designing a durable lithium metal anode for solid state batteries requires a controllable and uniform deposition of lithium, and the metal lithium layer should maintain a good interface contact with solid state electrolyte during cycles. In this work, we construct a robust functional interface layer on the modified LiB electrode which considerably improves the electrochemical stability of lithium metal electrode in solid state batteries. It is found that the functional interface layer consisting of polydioxolane, polyiodide ion and Li TFSI effectively restrains the growth of lithium dendrites through the redox shuttle reaction of I-/I3-and maintains a good contact between lithium anode and solid electrolyte during cycles. Benefit from these two advantages, the modified Li-B anode exhibits a remarkable cyclic performance in comparison with those of the bare Li-B anode.
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Sponsored by the National Natural Science Foundation of China(Grant No.51373048)the National Key Research and Development Program of China(Grant Nos.U1604253 and 2016YFB0101602)
文摘To improve the strength of carbon fiber(CF) reinforced Polycaprolactam(PA6) composites, controlled amounts of carbon nanotubes(CNTs) were grafted onto the surface of CF to prepare the hybrid reinforcement(HR). We used HR to fabricate laminate and H-sample to test the interfacial bonding strength(IBS) of the composites by means of a novel process called three-dimensional printed molding(3 D-PM). By using the melt drop printing method, we measured the contact angles between PA6 and CF(without sizing) and between PA6 and HR. The IBS and the mechanical properties of the composites were obtained by the tensile test. The experimental result indicated that CF grafted by 0.25% weight fraction of CNT or more could develop a special microstructure similar to the micro-pits on the surface of CF, which improved the wettability of CF and PA6 due to the increased surface area and the roughness of CF. When the weight fraction of CNT reached 0.25%, the IBS increased by 41.8%, the tensile strength by 130%, and the interfacial shear strength(IFSS) by 238%. The interfacial dimple fracture was observed by Scanning Electron Microscope(SEM), which revealed that the composites were able to absorb more deforming energy before fracture. The modified surface microstructure of CF would prevent crack propagation at the interface and increase the mechanical properties of thermoplastic composites(TPCs).
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supported by the National Key R&D program of China(2019YFA0706802)National Natural Science Foundation of China(52063029)+2 种基金Natural Science Basic Research Program of Shaanxi(2022JM-200,2021JQ-716)China Postdoctoral Science Foundation(2020M672269)Doctoral Research Program of Yan’an University(YDBK2019-02)
文摘Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially accessible internal spaces,and so forth.Dissimilar guest species(such as organic groups or metal nanoparticles)could be readily decorated onto the interfaces of the channels and pores,realizing the functionalization of dendritic mesoporous silica nanoparticles for targeted applications.As adsorbents and catalysts,dendritic mesoporous silica nanoparticles-based materials have experienced nonignorable development in CO_(2)capture and catalytic conversion.This comprehensive review provides a critical survey on this pregnant subject,summarizing the designed construction of novel dendritic mesoporous silica nanoparticles-based materials,the involved chemical reactions(such as CO_(2)methanation,dry reforming of CH_(4)),the value-added chemicals from CO_(2)(such as cyclic carbonates,2-oxazolidinones,quinazoline-2,4(1H,3H)-diones),and so on.The adsorptive and catalytic performances have been compared with traditional silica mesoporous materials(such as SBA-15 or MCM-41),and the corresponding reaction mechanisms have been thoroughly revealed.It is sincerely expected that the in-depth discussion could give materials scientists certain inspiration to design brand-new dendritic mesoporous silica nanoparticles-based materials with superior capabilities towards CO_(2)capture,utilization,and storage.
文摘The continuous miniaturization and high-power development of electronic devices have given rise to severe interface thermal issues,which urgently demand highly thermally conductive thermal interface materials(TIMs)to eliminate excessive heat accumulation and ensure the normal operation of devices[1].
