Rechargeable aqueous zinc-ion batteries(AZIBs)exhibit appreciable potential in the domain of electrochemical energy storage.However,there are serious challenges for AZIBs,for instance zinc dendrite growth,hydrogen evo...Rechargeable aqueous zinc-ion batteries(AZIBs)exhibit appreciable potential in the domain of electrochemical energy storage.However,there are serious challenges for AZIBs,for instance zinc dendrite growth,hydrogen evolution reaction(HER),and corrosion side reactions.Herein,we propose a surface engineering modification strategy for coating the montmorillonite(MMT)layer onto the surface of the Zn anode to tackle these issues,thereby achieving high cycling stability for rechargeable AZIBs.The results reveal that the MMT layer on the surface of the Zn anode is able to provide ordered zincophilic channels for zinc ions migration,facilitating the reaction kinetics of zinc ions.Density functional theory(DFT)calculations and water contact angle(CA)tests prove that MMT@Zn anode exhibits superior adsorption capacity for Zn^(2+)and better hydrophobicity than the bare Zn anode,thereby achieving excellent cycling stability.Moreover,the MMT@Zn||MMT@Zn symmetric cell holds the stable cycling over 5600 h at 0.5 mA cm^(-2)and 0.125 m A h cm^(-2),even exceeding 1800 h long cycling under harsh conditions of 5 m A cm^(-2)and 1.25 m A h cm^(-2).The MMT@Zn||V_(2)O_(5)full cell reaches over 3000 cycles at 2 A g^(-1)with excellent rate capability.Therefore,this surface engineering modification strategy for enhancing the electrochemical performance of AZIBs represents a promising application.展开更多
Recent developments in the biochemical and medicinal industries have been heavily focused on producing affordable glucose biosensors due to the condi nuous annual increase of diabetic patients worldwide.The devel-opme...Recent developments in the biochemical and medicinal industries have been heavily focused on producing affordable glucose biosensors due to the condi nuous annual increase of diabetic patients worldwide.The devel-opment of a fast,accurate,and reliable glucose sensor will increase confidence in controlling di abetes mellitus and its assoclated health complications among the diabetic community.Electraspinning is a versatile method that can produce complex nanofbrous assemblies with attractiwe and functional characteristics from varlous polymers.Electrospun nanofibers demonstrated high efficiency in the immobilization of biological molecules,which can improve the sensing performance further.Integr ation of polymer electrospun nanofibers with metal nanoparticles,metal oxde or transition metal in producing nanobiocomposites is also a highly popul ar approach in the past few years.This report presents the current progress and research trends of the technique,focusing on varous ma-terials and fabrication strategies used to produce biosensing interfaces.This helps readers decide the suitable approach in designing highly sensitive,selective,fast,and inexpensive glucose sensors.展开更多
Wetting and spreading processes which involve surfactant solutions are widely used in numerous industrial and practical applications nowadays.The performance of different non-ionic surfactants may vary significantly a...Wetting and spreading processes which involve surfactant solutions are widely used in numerous industrial and practical applications nowadays.The performance of different non-ionic surfactants may vary significantly and so far superspreader solutions show the most promising spreading ability.The addition of trisiloxane surfactants to water was proven to enhance wetting,even on hydrophobic surfaces,on which conventional surfactants seem to have little or no effect.Although these extraordinary surfactants have been extensively studied over recent years,complete understanding of their underlying mechanisms and a suitable mathematical model are still lacking.Here we present a possible explanation for the impressive performance of trisiloxane,which is compared to wetting enhancement of a conventional surfactant.Additionally,we will explain why the hydrophobicity of the surface is a crucial factor for the spreading phenomenon.Light will be also shed on the effect of the pH of the solution to which surfactants are added.Finally,we will investigate long-term effects of the water environment on trisiloxane wetting ability and discuss if ageing may significantly affect their performance.展开更多
Electrospinning is a popular method for generating long and continuous nanofibers due to its simplicity and versatility.However,conventional electrospun products have weak strength and low availability,which restrict ...Electrospinning is a popular method for generating long and continuous nanofibers due to its simplicity and versatility.However,conventional electrospun products have weak strength and low availability,which restrict their functionality in complex applications.Hierarchical morphology introduces additional and distinctive structural layers onto electrospun fibers.This requires either an extra fabrication step or controlling electrospinning parameters to achieve the desired morphology.Hierarchical morphology can improve the properties of electrospun nanofibers while also mitigating the undesired characteristics.This review discusses the primary and secondary hierarchical structures of electrospun nanomaterials.Hierarchical structures were found to enhance the functionality of nanomaterials and improve pore connectivity and surface areas of electrospun nanofibers.A further advantage is the ability to impart multiple functionalities on nanostructures.With a better understanding of some of the dominant hierarchical structures,nanomaterials applications in drug delivery,tissue engineering,catalysis,and energy devices industries can be improved.展开更多
Fine finishing of tungsten alloy is required to improve the surface quality of molds and precision instruments. Nevertheless, it is difficult to obtain high-quality surfaces as a result of grain boundary steps attribu...Fine finishing of tungsten alloy is required to improve the surface quality of molds and precision instruments. Nevertheless, it is difficult to obtain high-quality surfaces as a result of grain boundary steps attributed to differences in properties of two-phase microstructures. This paper presents a theoretical and experimental investigation on chemical mechanical polishing of W–Ni–Fe alloy. The mechanism of the boundary step generation is illustrated and a model of grain boundary step formation is proposed. The mechanism reveals the effects of mechanical and chemical actions in both surface roughness and material removal. The model was verified by the experiments and the results show that appropriately balancing the mechanical and chemical effects restrains the generation of boundary steps and leads to a fine surface quality with a high removal rate by citric acid-based slurry.展开更多
The electrical conductivity of sintered Cr2O3 mixed with 2% and 5% （in molar fraction） TiO2 or CuO was investigated in the temperature range 500-900℃ in air and in At/4 vol. pct H2 atmospheres. The effect of differ...The electrical conductivity of sintered Cr2O3 mixed with 2% and 5% （in molar fraction） TiO2 or CuO was investigated in the temperature range 500-900℃ in air and in At/4 vol. pct H2 atmospheres. The effect of different Mn-oxides on the electrical conductivity of Cr2O3 was also studied under the same conditions. From the conductivity measurements it is established that additions of TiO2 change the defect structure of Cr2O3 and the effect of TiO2 on the electrical conductivity is controlled by TiO2 concentration as well as temperature and O2 partial pressure of the surrounding atmosphere. The conductivity of Cr2O3 increased in air and decreased in the At/H2 atmosphere by CuO additions. The effect of CuO was discussed with possible changes in the defect concentration in Cr2O3. Mixing of Cr2O3 with different Mn-oxides at the same Mn to metal atom fraction decreased the conductivity in air and in Ar/H2 atmospheres. No clear correlation between the spinel fraction and the changes in conductivity could be found.展开更多
Nanomanufacturing(NM),developed over the past three decades,bridges nanosciencediscoveries tonanotechnology products by scaled-up,reliable,and cost-effective manufacturing materials,structures,devices,and systems at t...Nanomanufacturing(NM),developed over the past three decades,bridges nanosciencediscoveries tonanotechnology products by scaled-up,reliable,and cost-effective manufacturing materials,structures,devices,and systems at the nanoscale(1-100 nm).At this scale,physical and chemical properties of the materials and tools have been dominated by classical Newtonian mechanics,although quantum confinementeffects become increasinglyobservable.Anumber of top-down and bottom-up approaches were developed,including nanomechanical machining,nanolithography,energy beam machining,deposition and etching,nanoprinting,nano assembly,nano replication,etc.[1].These techniques enabled a range of applications from medical imaging and renewable energy to sensor devices and quantum computing.展开更多
This paper introduces a series of approaches in the modelling of composites with complex multiscale structures and features.Fundamental theory underlying multiscale structures are brought to light and discussed.There ...This paper introduces a series of approaches in the modelling of composites with complex multiscale structures and features.Fundamental theory underlying multiscale structures are brought to light and discussed.There can be considerable benefit in the representative application of multiscale modelling techniques to civil aircraft design and this aim of this paper is to provide essential perspectives from several fields of research that may be beneficial to aerospace composites modelling methodologies if applied appropriately.展开更多
Electrospinning is widely accepted as a technique for the fabrication of nanofibrous three-dimensional(3D)scaffolds which mimic extracellular matrix(ECM)microenvironment for tissue engineering(TE).Unlike normal densel...Electrospinning is widely accepted as a technique for the fabrication of nanofibrous three-dimensional(3D)scaffolds which mimic extracellular matrix(ECM)microenvironment for tissue engineering(TE).Unlike normal densely-packed two-dimensional(2D)nanofibrous membranes,3D electrospun nanofiber scaffolds are dedicated to more precise spatial control,endowing the scaffolds with a sufficient porosity and 3D environment similar to the in vivo settings as well as optimizing the properties,including injectability,compressibility,and bioactivity.Moreover,the 3D morphology regulates cellular interaction and mediates growth,migration,and differentiation of cell for matrix remodeling.The variation among scaffold structures,functions and applications depends on the selection of electrospinning materials and methods as well as on the post-processing of electrospun scaffolds.This review summarizes the recent new forms for building electrospun 3D nanofiber scaffolds for TE applications.A variety of approaches aimed at the fabrication of 3D electrospun scaffolds,such as multilay-ering electrospinning,sacrificial agent electrospinning,wet electrospinning,ultrasound-enhanced electrospinning as well as post-processing techniques,including gas foaming,ultrasonication,short fiber assembly,3D printing,electrospraying,and so on are discussed,along with their advantages,limitations and applications.Meanwhile,the current challenges and prospects of 3D electrospun scaffolds are rationally discussed,providing an insight into developing the vibrant fields of biomedicine.展开更多
Ammonia is the second most produced chemical worldwide that makes up 80%of nitrogen-based fertilisers,which have supported approximately 27%of the world’s population over the last century.The Haber–Bosch process,wh...Ammonia is the second most produced chemical worldwide that makes up 80%of nitrogen-based fertilisers,which have supported approximately 27%of the world’s population over the last century.The Haber–Bosch process,which is the main process for producing ammonia,is extremely energy intensive and consumes around 1%of the world’s energy.Additionally,it requires hydrogen gas as a reactant that is produced via steam reforming which emits carbon dioxide as a by-product.Over 500 million tonnes of ammonia are produced per year via industrial processes which required 3–5%of total natural gas consumption worldwide and also accounted for 2%global energy usage.Therefore,more sustainable processes,such as electrocatalysis and photocatalysis,using electrons and the transfer of protons has been investigated.This review covers the most state-of-the-art technologies used to produce ammonia via electrocatalysis and photocatalysis by comparing different electrolyte systems and electrocatalysts as well as discussing issues with these methods and possible solutions.In addition,substantial improvements to electrocatalysts and photocatalysts as well as methods to prevent both the promotion of the hydrogen evolution reaction and the decomposition of ammonia at higher temperatures are reviewed.Challenges and perspectives are discussed.展开更多
Smart materials have demonstrated significant potential for enhancing thermal efficiency and regulating light infiltration within the context of architectural energy management[1].Recent advancements have focused on i...Smart materials have demonstrated significant potential for enhancing thermal efficiency and regulating light infiltration within the context of architectural energy management[1].Recent advancements have focused on incorporating thermochromic materials into transparent elements like windows and skylights,facilitating autonomous control of radiative heat transfer in response to external environmental changes and eliminating the need for external energy sources[2].Considerable efforts have been made to enhance the functionality of existing thermochromic materials through the restructuring of smart window architectures[3]and the design of multifunctional coatings[4],leading to a series of notable advancements.However,the practical deployment of such materials is constrained by significant challenges related to cost-effectiveness,sustainability,and operational lifespan[5,6].These limitations underscore the need for a new class of thermochromic materials that are cost-saving,scalable,non-toxic,and highly stable.In a recent publication in Joule,Pulickel M.Ajayan and co-workers[7]proposed an innovative methodology for thermochromic materials applicable to smart windows,utilizing an easily manufacturable and stable polymer blend system.This system exhibits high transmittance,substantial solar modulation,remarkable reversibility and durability within an accessible temperature range.展开更多
CO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO2. Membrane gas separation is a fast growing CO2 capture technique, particularly gas ...CO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO2. Membrane gas separation is a fast growing CO2 capture technique, particularly gas separation by composite membranes. The separation of CO2 by a membrane is not just a process to physically sieve out of CO2 through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb CO2. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of CO2 in pure and composite membranes to explore the complete understanding of diffusion and solubility of CO2 through membranes. Pure cellulose acetate（CA） and cellulose acetatetitania nanoparticle（CA-TiO2） composite membranes were fabricated and characterised using SEM and FTIR analysis. The results indicated that the blended CA-TiO2 membrane adsorbed more quantity of CO2 gas as compared to pure CA membrane. The high CO2 adsorption capacity may enhance the diffusion and solubility of CO2 in the CA-TiO2 composite membrane, which results in a better CO2 separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion models.According to correlation factor R2, the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.展开更多
The morphology of linear polybutadiene physisorbed on freshly cleaved mica from a dilute polymer solution is investigated through atomic force microscopy.A fine-structure study shows that the monolayer morphology in a...The morphology of linear polybutadiene physisorbed on freshly cleaved mica from a dilute polymer solution is investigated through atomic force microscopy.A fine-structure study shows that the monolayer morphology in air(after rapid solvent evaporation)depends strongly on the molecular weight(Mw)of the linear polymer,the adsorbed amount,and the conformation adopted by the adsorbed polymer chains under good solvent conditions.The dependence of the observed polymer structure on Mw is most significant for samples with high surface density,where the intermolecular interactions among the adsorbed polymers are important.For high surface density,the adsorbed polymers tend to aggregate and minimize unfavorable contacts with air for all of the different Mw samples,leading to an isotropic structural pattern.These structural phenomena with increasing surface density are explained on the basis of the intermolecular interactions of the adsorbed polymers under good solvent conditions,and after the abrupt solvent evaporation corresponding to poor solvent conditions.The experimental observations are further discussed using the results obtained from molecular dynamics simulations of a simple coarse-grained model.展开更多
基金National Natural Science Foundation of China(Grant No.22005318,22379152)Western Young Scholars Foundations of Chinese Academy of Sciences+4 种基金Lanzhou Youth Science and Technology Talent Innovation Project(Grant No.2023-NQ-86,No.2023-QN-96)Lanzhou Chengguan District Science and Technology Plan Project(Grant No.2023-rc-4,2022-rc-4)Collaborative Innovation Alliance Fund for Young Science and Technology Worker(Grant No.HZJJ23-7)National Nature Science Foundations of Gansu Province(Grant No.21JR11RA020)Fundamental Research Funds for the Central Universities(Grant No.31920220073,31920230128)。
文摘Rechargeable aqueous zinc-ion batteries(AZIBs)exhibit appreciable potential in the domain of electrochemical energy storage.However,there are serious challenges for AZIBs,for instance zinc dendrite growth,hydrogen evolution reaction(HER),and corrosion side reactions.Herein,we propose a surface engineering modification strategy for coating the montmorillonite(MMT)layer onto the surface of the Zn anode to tackle these issues,thereby achieving high cycling stability for rechargeable AZIBs.The results reveal that the MMT layer on the surface of the Zn anode is able to provide ordered zincophilic channels for zinc ions migration,facilitating the reaction kinetics of zinc ions.Density functional theory(DFT)calculations and water contact angle(CA)tests prove that MMT@Zn anode exhibits superior adsorption capacity for Zn^(2+)and better hydrophobicity than the bare Zn anode,thereby achieving excellent cycling stability.Moreover,the MMT@Zn||MMT@Zn symmetric cell holds the stable cycling over 5600 h at 0.5 mA cm^(-2)and 0.125 m A h cm^(-2),even exceeding 1800 h long cycling under harsh conditions of 5 m A cm^(-2)and 1.25 m A h cm^(-2).The MMT@Zn||V_(2)O_(5)full cell reaches over 3000 cycles at 2 A g^(-1)with excellent rate capability.Therefore,this surface engineering modification strategy for enhancing the electrochemical performance of AZIBs represents a promising application.
基金the Faculty of Chemical Engineering and University Teknologi MARA for the funding through grants 600-IRMI 5/3/GIP(070/2019),600-IRMI/DANA 5/3/BESTARI(115/2018),and 600 IRMI MYRA 5/3 BESTARI(021/2017).
文摘Recent developments in the biochemical and medicinal industries have been heavily focused on producing affordable glucose biosensors due to the condi nuous annual increase of diabetic patients worldwide.The devel-opment of a fast,accurate,and reliable glucose sensor will increase confidence in controlling di abetes mellitus and its assoclated health complications among the diabetic community.Electraspinning is a versatile method that can produce complex nanofbrous assemblies with attractiwe and functional characteristics from varlous polymers.Electrospun nanofibers demonstrated high efficiency in the immobilization of biological molecules,which can improve the sensing performance further.Integr ation of polymer electrospun nanofibers with metal nanoparticles,metal oxde or transition metal in producing nanobiocomposites is also a highly popul ar approach in the past few years.This report presents the current progress and research trends of the technique,focusing on varous ma-terials and fabrication strategies used to produce biosensing interfaces.This helps readers decide the suitable approach in designing highly sensitive,selective,fast,and inexpensive glucose sensors.
文摘Wetting and spreading processes which involve surfactant solutions are widely used in numerous industrial and practical applications nowadays.The performance of different non-ionic surfactants may vary significantly and so far superspreader solutions show the most promising spreading ability.The addition of trisiloxane surfactants to water was proven to enhance wetting,even on hydrophobic surfaces,on which conventional surfactants seem to have little or no effect.Although these extraordinary surfactants have been extensively studied over recent years,complete understanding of their underlying mechanisms and a suitable mathematical model are still lacking.Here we present a possible explanation for the impressive performance of trisiloxane,which is compared to wetting enhancement of a conventional surfactant.Additionally,we will explain why the hydrophobicity of the surface is a crucial factor for the spreading phenomenon.Light will be also shed on the effect of the pH of the solution to which surfactants are added.Finally,we will investigate long-term effects of the water environment on trisiloxane wetting ability and discuss if ageing may significantly affect their performance.
文摘Electrospinning is a popular method for generating long and continuous nanofibers due to its simplicity and versatility.However,conventional electrospun products have weak strength and low availability,which restrict their functionality in complex applications.Hierarchical morphology introduces additional and distinctive structural layers onto electrospun fibers.This requires either an extra fabrication step or controlling electrospinning parameters to achieve the desired morphology.Hierarchical morphology can improve the properties of electrospun nanofibers while also mitigating the undesired characteristics.This review discusses the primary and secondary hierarchical structures of electrospun nanomaterials.Hierarchical structures were found to enhance the functionality of nanomaterials and improve pore connectivity and surface areas of electrospun nanofibers.A further advantage is the ability to impart multiple functionalities on nanostructures.With a better understanding of some of the dominant hierarchical structures,nanomaterials applications in drug delivery,tissue engineering,catalysis,and energy devices industries can be improved.
基金supported by National Key Research and Development Program (No. 2018YFA0702900)National Natural Science Foundation of China (No. 51975096)+1 种基金Science Challenge Project (No. TZ2018006-0101-01)Liao Ning Revitalization Talents Program (No. XLYC1807230)。
文摘Fine finishing of tungsten alloy is required to improve the surface quality of molds and precision instruments. Nevertheless, it is difficult to obtain high-quality surfaces as a result of grain boundary steps attributed to differences in properties of two-phase microstructures. This paper presents a theoretical and experimental investigation on chemical mechanical polishing of W–Ni–Fe alloy. The mechanism of the boundary step generation is illustrated and a model of grain boundary step formation is proposed. The mechanism reveals the effects of mechanical and chemical actions in both surface roughness and material removal. The model was verified by the experiments and the results show that appropriately balancing the mechanical and chemical effects restrains the generation of boundary steps and leads to a fine surface quality with a high removal rate by citric acid-based slurry.
文摘The electrical conductivity of sintered Cr2O3 mixed with 2% and 5% （in molar fraction） TiO2 or CuO was investigated in the temperature range 500-900℃ in air and in At/4 vol. pct H2 atmospheres. The effect of different Mn-oxides on the electrical conductivity of Cr2O3 was also studied under the same conditions. From the conductivity measurements it is established that additions of TiO2 change the defect structure of Cr2O3 and the effect of TiO2 on the electrical conductivity is controlled by TiO2 concentration as well as temperature and O2 partial pressure of the surrounding atmosphere. The conductivity of Cr2O3 increased in air and decreased in the At/H2 atmosphere by CuO additions. The effect of CuO was discussed with possible changes in the defect concentration in Cr2O3. Mixing of Cr2O3 with different Mn-oxides at the same Mn to metal atom fraction decreased the conductivity in air and in Ar/H2 atmospheres. No clear correlation between the spinel fraction and the changes in conductivity could be found.
文摘Nanomanufacturing(NM),developed over the past three decades,bridges nanosciencediscoveries tonanotechnology products by scaled-up,reliable,and cost-effective manufacturing materials,structures,devices,and systems at the nanoscale(1-100 nm).At this scale,physical and chemical properties of the materials and tools have been dominated by classical Newtonian mechanics,although quantum confinementeffects become increasinglyobservable.Anumber of top-down and bottom-up approaches were developed,including nanomechanical machining,nanolithography,energy beam machining,deposition and etching,nanoprinting,nano assembly,nano replication,etc.[1].These techniques enabled a range of applications from medical imaging and renewable energy to sensor devices and quantum computing.
文摘This paper introduces a series of approaches in the modelling of composites with complex multiscale structures and features.Fundamental theory underlying multiscale structures are brought to light and discussed.There can be considerable benefit in the representative application of multiscale modelling techniques to civil aircraft design and this aim of this paper is to provide essential perspectives from several fields of research that may be beneficial to aerospace composites modelling methodologies if applied appropriately.
基金The authors would like to thank the financial support from National Nature Science Foundation of China(No.32050410286)Science and Technology Commission of Shanghai Municipality(No.20S31900900,20DZ2254900)+2 种基金Sino German Science Foundation Research Exchange Center(M-0263)National Advanced Functional Fiber Innovation Center(2021-fx020301)International Cooperation of 2021-2022 China and Poland Science and Technology Personnel Exchange Program(No.17).
文摘Electrospinning is widely accepted as a technique for the fabrication of nanofibrous three-dimensional(3D)scaffolds which mimic extracellular matrix(ECM)microenvironment for tissue engineering(TE).Unlike normal densely-packed two-dimensional(2D)nanofibrous membranes,3D electrospun nanofiber scaffolds are dedicated to more precise spatial control,endowing the scaffolds with a sufficient porosity and 3D environment similar to the in vivo settings as well as optimizing the properties,including injectability,compressibility,and bioactivity.Moreover,the 3D morphology regulates cellular interaction and mediates growth,migration,and differentiation of cell for matrix remodeling.The variation among scaffold structures,functions and applications depends on the selection of electrospinning materials and methods as well as on the post-processing of electrospun scaffolds.This review summarizes the recent new forms for building electrospun 3D nanofiber scaffolds for TE applications.A variety of approaches aimed at the fabrication of 3D electrospun scaffolds,such as multilay-ering electrospinning,sacrificial agent electrospinning,wet electrospinning,ultrasound-enhanced electrospinning as well as post-processing techniques,including gas foaming,ultrasonication,short fiber assembly,3D printing,electrospraying,and so on are discussed,along with their advantages,limitations and applications.Meanwhile,the current challenges and prospects of 3D electrospun scaffolds are rationally discussed,providing an insight into developing the vibrant fields of biomedicine.
文摘Ammonia is the second most produced chemical worldwide that makes up 80%of nitrogen-based fertilisers,which have supported approximately 27%of the world’s population over the last century.The Haber–Bosch process,which is the main process for producing ammonia,is extremely energy intensive and consumes around 1%of the world’s energy.Additionally,it requires hydrogen gas as a reactant that is produced via steam reforming which emits carbon dioxide as a by-product.Over 500 million tonnes of ammonia are produced per year via industrial processes which required 3–5%of total natural gas consumption worldwide and also accounted for 2%global energy usage.Therefore,more sustainable processes,such as electrocatalysis and photocatalysis,using electrons and the transfer of protons has been investigated.This review covers the most state-of-the-art technologies used to produce ammonia via electrocatalysis and photocatalysis by comparing different electrolyte systems and electrocatalysts as well as discussing issues with these methods and possible solutions.In addition,substantial improvements to electrocatalysts and photocatalysts as well as methods to prevent both the promotion of the hydrogen evolution reaction and the decomposition of ammonia at higher temperatures are reviewed.Challenges and perspectives are discussed.
文摘Smart materials have demonstrated significant potential for enhancing thermal efficiency and regulating light infiltration within the context of architectural energy management[1].Recent advancements have focused on incorporating thermochromic materials into transparent elements like windows and skylights,facilitating autonomous control of radiative heat transfer in response to external environmental changes and eliminating the need for external energy sources[2].Considerable efforts have been made to enhance the functionality of existing thermochromic materials through the restructuring of smart window architectures[3]and the design of multifunctional coatings[4],leading to a series of notable advancements.However,the practical deployment of such materials is constrained by significant challenges related to cost-effectiveness,sustainability,and operational lifespan[5,6].These limitations underscore the need for a new class of thermochromic materials that are cost-saving,scalable,non-toxic,and highly stable.In a recent publication in Joule,Pulickel M.Ajayan and co-workers[7]proposed an innovative methodology for thermochromic materials applicable to smart windows,utilizing an easily manufacturable and stable polymer blend system.This system exhibits high transmittance,substantial solar modulation,remarkable reversibility and durability within an accessible temperature range.
基金supported by Higher Education Commission (HEC) Pakistan
文摘CO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO2. Membrane gas separation is a fast growing CO2 capture technique, particularly gas separation by composite membranes. The separation of CO2 by a membrane is not just a process to physically sieve out of CO2 through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb CO2. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of CO2 in pure and composite membranes to explore the complete understanding of diffusion and solubility of CO2 through membranes. Pure cellulose acetate（CA） and cellulose acetatetitania nanoparticle（CA-TiO2） composite membranes were fabricated and characterised using SEM and FTIR analysis. The results indicated that the blended CA-TiO2 membrane adsorbed more quantity of CO2 gas as compared to pure CA membrane. The high CO2 adsorption capacity may enhance the diffusion and solubility of CO2 in the CA-TiO2 composite membrane, which results in a better CO2 separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion models.According to correlation factor R2, the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.
基金the EPSRCDTA and the Institute of Materials and Processes,School of Engineering at the University of Edinburgh.
文摘The morphology of linear polybutadiene physisorbed on freshly cleaved mica from a dilute polymer solution is investigated through atomic force microscopy.A fine-structure study shows that the monolayer morphology in air(after rapid solvent evaporation)depends strongly on the molecular weight(Mw)of the linear polymer,the adsorbed amount,and the conformation adopted by the adsorbed polymer chains under good solvent conditions.The dependence of the observed polymer structure on Mw is most significant for samples with high surface density,where the intermolecular interactions among the adsorbed polymers are important.For high surface density,the adsorbed polymers tend to aggregate and minimize unfavorable contacts with air for all of the different Mw samples,leading to an isotropic structural pattern.These structural phenomena with increasing surface density are explained on the basis of the intermolecular interactions of the adsorbed polymers under good solvent conditions,and after the abrupt solvent evaporation corresponding to poor solvent conditions.The experimental observations are further discussed using the results obtained from molecular dynamics simulations of a simple coarse-grained model.
