The character of variations of the local electric resistance and magnetic susceptibility of film polymer composites with graded anisotropic structures on the basis of polyvinyl alcohol, graphite and nickel nano-powder...The character of variations of the local electric resistance and magnetic susceptibility of film polymer composites with graded anisotropic structures on the basis of polyvinyl alcohol, graphite and nickel nano-powders have been studied. Graded anisotropic structures are formed after orientation （stretching） in spatial conditions of thin polymer composites. Structure anisotropy leads to anisotropy both electrical conductivity and magnetic properties of these films. It is established that the changes of these parameters essentially depend on both initial shape of the films and on direction of their orientation. So, after orientation of the rectangle films parallel to it any side forms the film, electrical resistance of which in parallel and rectangle directions to orientation axis changes by Gauss low. The composites containing the magnetic particles after orientation are characterized with analogical regularity （extreme dependence of the magnetic susceptibility on the coordinates of the film along and perpendicular to stretching directions）. Gradient distribution of the local resistances and magnetic susceptibilities in the stretched films along and rectangle to stretching direction is due to gradient of local deformations in the same directions. In electronics these films can be useful for preparing of muitifunctional printed circuits of new generation.展开更多
The tribological characteristics of carbon fiber reinforced polymer composites under distilled-water-lubricated-sliding and dry-sliding against stainless steel were comparatively investigated. Scanning electron micros...The tribological characteristics of carbon fiber reinforced polymer composites under distilled-water-lubricated-sliding and dry-sliding against stainless steel were comparatively investigated. Scanning electron microscopy (SEM) was utilized to examine composite microstructures and modes of failure. The typical chemical states of elements of the transfer film on the stainless steel were examined with X-ray photoelectron spectroscopy (XPS). Wear testing and SEM analysis show that all the composites hold the lowered friction coefficient and show much better wear resistance under water lubricated sliding against stainless steel than those under dry sliding. The wear of composites is characterized by plastic deformation, scuffing, micro cracking, and spalling under both dry-sliding and water lubricated conditions. Plastic deformation, scuffing, micro cracking, and spalling, however, are significantly abated under water-lubricated condition. XPS analysis conforms that none of the materials produces transfer films on the stainless steel counterface with the type familiar from dry sliding, and the transfer of composites onto the counterpart ring surface is significantly hindered while the oxidation of the stainless steel is speeded under water lubrication. The composites hinder transfer onto the steel surface and the boundary lubricating action of water accounts for the much smaller wear rate under water lubrication compared with that under dry sliding. The easier transfer of the composite onto the counterpart steel surface accounts for the larger wear rate of the polymer composite under dry sliding.展开更多
Mesoporous silica films embedded with Ag nanoparticles were directly synthesized by a solgel dip-coating process, combining alkyl （ethylene oxide） surfactant as temple and tetraethoxysilane as inorganic precursor. T...Mesoporous silica films embedded with Ag nanoparticles were directly synthesized by a solgel dip-coating process, combining alkyl （ethylene oxide） surfactant as temple and tetraethoxysilane as inorganic precursor. The addition of Ag^＋ ion to the reaction sol was prior to the formation of films, followed by the heat treatment at 150℃ led to the creation ofAg nanoparticies. The formation ofAg nanoparticles and the change of its surface plasma resonance absorption were characterized by Uv-vis. The small angle XRD test indicated that the films had an ordered hexagonal mesoporous structure, of which the unit cell parameter was about 4.26 nm. The TEM images and EDS spectra of the samples have directly verified the presence of mono-dispersed Ag nanoparticles within the films, due to the confine effects of mesopores.展开更多
Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate （ EMA ）. With the polymerization of EMA monomer and the formation of europium and terbium coordi...Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate （ EMA ）. With the polymerization of EMA monomer and the formation of europium and terbium coordination polymers of pyridiae- 3-carboxylic acid, the transparent hybrid thick fihns composed of [ Eu（ NIC ）3 ]n （ [ Tb（ NIC）3 ]n ） and poly ethyl mettuwrylate （ PEMA ） have been prepared. The luminescence properties and energy transfer of these polymeric composites were studied with absorption spectra, fluorescent excitation trod emission spectra in detail. All the hybrid thick films composed of terbium coordination polymer show the characteristic strong green emission of terbium ions, which implies the same energy transfer mechanism as the pure complex and the hybrid composite film is a suitable sabstrate for the luminescence of terbium ions. In the range of camposing concentration of luminescent species （0.01,0.025,0.05,0.1 mmol /15 mL EMA ）, emission intensities increase with the increasing of corresponding composing concentration and the concentration quenching effect does not take place.展开更多
We present a new and practical approach for preparing submicro-textured silver and aluminum （Ag/Al） double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structu...We present a new and practical approach for preparing submicro-textured silver and aluminum （Ag/Al） double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structured layers was performed by increasing the deposition temperature of the Al layers to 270℃. The highly submicro-textured silver and aluminum double-structured layers were prepared by thermal evaporation on quartz glasses and their surface microstructure, light scattering properties, and thermal stability were investigated. Results showed that the highly submicro-textured Ag/Al composite films prepared at low substrate temperatures used as back reflectors not only can enhance the light scattering and have good thermal stability, but also have good adhesion properties. In addition, their fabrication is low cost and readily carried out.展开更多
Stable thin films made from polyionic complex 2C12N+PVS- with incorporated Hb on PG electrodes were characterized by electrochemistry. The electron transfer between Hb and PG electrodes was greatly facilitated in micr...Stable thin films made from polyionic complex 2C12N+PVS- with incorporated Hb on PG electrodes were characterized by electrochemistry. The electron transfer between Hb and PG electrodes was greatly facilitated in microenvironment of 2C12N+PVS- films. The Hb-2C12N+PVS-films could be used to catalytically reduce trichloroacetic acid.展开更多
New polymer film materials with good properties are reported. The difference between positive and negative coronas is also given. The films have good transmittance, excellent thermal and long-term stability, low diele...New polymer film materials with good properties are reported. The difference between positive and negative coronas is also given. The films have good transmittance, excellent thermal and long-term stability, low dielectric constant, and high glass transition temperature.展开更多
A new polymer composite thin film DMACB/PEK-c is reported. After poling of the film, the refractive indices n t and n n, that is the in-film-plane and the normal-to-film-plane refractive indices at 633 nm and the thic...A new polymer composite thin film DMACB/PEK-c is reported. After poling of the film, the refractive indices n t and n n, that is the in-film-plane and the normal-to-film-plane refractive indices at 633 nm and the thickness d were determined using the quasi-waveguide m -line method. The results of measurement and calculation are: n t=1.657 3±0.001 7, n n=1.627 8±0.001 9, and d =1.427 8±0.003 1 μm.展开更多
Organic memristors with low power consumption,fast write/erasure speed,and complementary metal-oxide-semiconductor(CMOS)compatibility have attracted tremendous attention to mimic biological synapses to realize neuromo...Organic memristors with low power consumption,fast write/erasure speed,and complementary metal-oxide-semiconductor(CMOS)compatibility have attracted tremendous attention to mimic biological synapses to realize neuromorphic computation in recent years.In this paper,organic resistive switching memory(ORSM)based on(Z)-3-(naphthalen-2-yl)-2-(4-nitrophenyl)acrylonitrile(NNA)and polymer poly(N-vinylcarbazole)(PVK)composite film was prepared by spin-coating method.Device performance based on NNA:PVK composite films with different mass fractions of NNA were systematically investigated.The ORSM based on PVK:40%(mass fraction)NNA composite film exhibited non-volatile and bipolar memory properties with a switching ratio(Ion/Ioff)of 24.1,endurance of 68 times and retention time of 104 s,a“SET”voltage(Vset)of−0.55 V and a“RESET”voltage(Vreset)of 2.35 V.The resistive switching was ascribed to the filling and vacant process of the charge traps induced by NNA and the inherent traps in PVK bulk.The holes trapping and de-trapping process occurred when the device was applied with a negative or positive bias,which caused the transforming of the conductive way of charges,that is the resistive behaviors in the macroscopic.This study provides a promising platform for the fabrication of ORSM with high performance.展开更多
The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately ...The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.展开更多
PVA(1-x)PSx (x = 0.0, 0.25, 0.50, 0.75 and 1.0) polymer blend films were prepared by simple solution cast method using mixer of dimethyl sulphoxide (DMSO) and double distilled water (DDW) as a common solvent. Gamma ir...PVA(1-x)PSx (x = 0.0, 0.25, 0.50, 0.75 and 1.0) polymer blend films were prepared by simple solution cast method using mixer of dimethyl sulphoxide (DMSO) and double distilled water (DDW) as a common solvent. Gamma irradiation studies have been carried out to investigate the potential for improvements in the electrical properties of pure and blend polymer film. The induced changes in the dielectric constant (εr), dielectric loss (tanδ) and AC conductivity (σac) properties for the unirradiated and irradiated films were studied, in the frequency range 50 Hz - 5 MHz at room temperature (27°C). Further, it was seen that the frequency dependent dielectric constant, dielectric loss and AC conductivity were found to increase with increasing γ irradiation dose for all the PVA(1-x)PSx (x = 0.0, 0.25, 0.50, 0.75 and 1.0) polymer blends. The maximum σac at 1 kHz frequency was observed to be 2.4421 × 10-6 s/m (at room temperature) for PVA film irradiated at 1.5 kGy.展开更多
Achieving high strength,deformability and toughness in polymers is important for practical industrial applications.This has remained challenging because of the mutually opposing effects of improvements to each of thes...Achieving high strength,deformability and toughness in polymers is important for practical industrial applications.This has remained challenging because of the mutually opposing effects of improvements to each of these properties.Here,a self-assembling nacre-like polymer composite is designed to achieve ex-tremely tough with increasing strength.This special design significantly improved polymer’s mechanical properties,including an ultra-high fracture strain of 1180%,a tensile strength of 55.4 MPa and a toughness of 506.9 MJ/m^(3),which far exceed the highest values previously reported for polymer composites.This ex-cellent combination of properties can be attributed to a novel toughening mechanism,achieved by the synergy of the domain-limiting effect of metallic glass fragments with the strain-gradient-induced orien-tation and crystallisation within the polymer during stretching.Our approach opens a promising avenue for designing robust polymer materials in armour and aerospace engineering for a range of innovative applications.展开更多
The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on acti...The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.展开更多
文摘The character of variations of the local electric resistance and magnetic susceptibility of film polymer composites with graded anisotropic structures on the basis of polyvinyl alcohol, graphite and nickel nano-powders have been studied. Graded anisotropic structures are formed after orientation （stretching） in spatial conditions of thin polymer composites. Structure anisotropy leads to anisotropy both electrical conductivity and magnetic properties of these films. It is established that the changes of these parameters essentially depend on both initial shape of the films and on direction of their orientation. So, after orientation of the rectangle films parallel to it any side forms the film, electrical resistance of which in parallel and rectangle directions to orientation axis changes by Gauss low. The composites containing the magnetic particles after orientation are characterized with analogical regularity （extreme dependence of the magnetic susceptibility on the coordinates of the film along and perpendicular to stretching directions）. Gradient distribution of the local resistances and magnetic susceptibilities in the stretched films along and rectangle to stretching direction is due to gradient of local deformations in the same directions. In electronics these films can be useful for preparing of muitifunctional printed circuits of new generation.
基金Project(59925513) supported by theNational Natural Science Foundation of China Project(9905) supported by the State Key Laboratory of Fluid Power Transmission and Control of Zhejiang University, China
文摘The tribological characteristics of carbon fiber reinforced polymer composites under distilled-water-lubricated-sliding and dry-sliding against stainless steel were comparatively investigated. Scanning electron microscopy (SEM) was utilized to examine composite microstructures and modes of failure. The typical chemical states of elements of the transfer film on the stainless steel were examined with X-ray photoelectron spectroscopy (XPS). Wear testing and SEM analysis show that all the composites hold the lowered friction coefficient and show much better wear resistance under water lubricated sliding against stainless steel than those under dry sliding. The wear of composites is characterized by plastic deformation, scuffing, micro cracking, and spalling under both dry-sliding and water lubricated conditions. Plastic deformation, scuffing, micro cracking, and spalling, however, are significantly abated under water-lubricated condition. XPS analysis conforms that none of the materials produces transfer films on the stainless steel counterface with the type familiar from dry sliding, and the transfer of composites onto the counterpart ring surface is significantly hindered while the oxidation of the stainless steel is speeded under water lubrication. The composites hinder transfer onto the steel surface and the boundary lubricating action of water accounts for the much smaller wear rate under water lubrication compared with that under dry sliding. The easier transfer of the composite onto the counterpart steel surface accounts for the larger wear rate of the polymer composite under dry sliding.
基金the National Natural Science Foundation of China(No.50272048)
文摘Mesoporous silica films embedded with Ag nanoparticles were directly synthesized by a solgel dip-coating process, combining alkyl （ethylene oxide） surfactant as temple and tetraethoxysilane as inorganic precursor. The addition of Ag^＋ ion to the reaction sol was prior to the formation of films, followed by the heat treatment at 150℃ led to the creation ofAg nanoparticies. The formation ofAg nanoparticles and the change of its surface plasma resonance absorption were characterized by Uv-vis. The small angle XRD test indicated that the films had an ordered hexagonal mesoporous structure, of which the unit cell parameter was about 4.26 nm. The TEM images and EDS spectra of the samples have directly verified the presence of mono-dispersed Ag nanoparticles within the films, due to the confine effects of mesopores.
文摘Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate （ EMA ）. With the polymerization of EMA monomer and the formation of europium and terbium coordination polymers of pyridiae- 3-carboxylic acid, the transparent hybrid thick fihns composed of [ Eu（ NIC ）3 ]n （ [ Tb（ NIC）3 ]n ） and poly ethyl mettuwrylate （ PEMA ） have been prepared. The luminescence properties and energy transfer of these polymeric composites were studied with absorption spectra, fluorescent excitation trod emission spectra in detail. All the hybrid thick films composed of terbium coordination polymer show the characteristic strong green emission of terbium ions, which implies the same energy transfer mechanism as the pure complex and the hybrid composite film is a suitable sabstrate for the luminescence of terbium ions. In the range of camposing concentration of luminescent species （0.01,0.025,0.05,0.1 mmol /15 mL EMA ）, emission intensities increase with the increasing of corresponding composing concentration and the concentration quenching effect does not take place.
基金the National Natural Science Foundation of China(Grant No.60977028)the Key Project Foundation of Shanghai,China(Grant No.09JC1413800)
文摘We present a new and practical approach for preparing submicro-textured silver and aluminum （Ag/Al） double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structured layers was performed by increasing the deposition temperature of the Al layers to 270℃. The highly submicro-textured silver and aluminum double-structured layers were prepared by thermal evaporation on quartz glasses and their surface microstructure, light scattering properties, and thermal stability were investigated. Results showed that the highly submicro-textured Ag/Al composite films prepared at low substrate temperatures used as back reflectors not only can enhance the light scattering and have good thermal stability, but also have good adhesion properties. In addition, their fabrication is low cost and readily carried out.
文摘Stable thin films made from polyionic complex 2C12N+PVS- with incorporated Hb on PG electrodes were characterized by electrochemistry. The electron transfer between Hb and PG electrodes was greatly facilitated in microenvironment of 2C12N+PVS- films. The Hb-2C12N+PVS-films could be used to catalytically reduce trichloroacetic acid.
基金The National Natural Science Foundation of China!(No. 69688005 and No. 69890230)
文摘New polymer film materials with good properties are reported. The difference between positive and negative coronas is also given. The films have good transmittance, excellent thermal and long-term stability, low dielectric constant, and high glass transition temperature.
文摘A new polymer composite thin film DMACB/PEK-c is reported. After poling of the film, the refractive indices n t and n n, that is the in-film-plane and the normal-to-film-plane refractive indices at 633 nm and the thickness d were determined using the quasi-waveguide m -line method. The results of measurement and calculation are: n t=1.657 3±0.001 7, n n=1.627 8±0.001 9, and d =1.427 8±0.003 1 μm.
基金supported by the Ji Hua Laboratory Science Program,China (No.X190251UZ190)the Foundation of Shanxi Datong University Doctoral Research,the Graduate Education Innovation Project of Shanxi Province,China (No.2022Y761)the Graduate Education Innovation Project of Shanxi Datong University,China (Nos.22CX02,22CX16).
文摘Organic memristors with low power consumption,fast write/erasure speed,and complementary metal-oxide-semiconductor(CMOS)compatibility have attracted tremendous attention to mimic biological synapses to realize neuromorphic computation in recent years.In this paper,organic resistive switching memory(ORSM)based on(Z)-3-(naphthalen-2-yl)-2-(4-nitrophenyl)acrylonitrile(NNA)and polymer poly(N-vinylcarbazole)(PVK)composite film was prepared by spin-coating method.Device performance based on NNA:PVK composite films with different mass fractions of NNA were systematically investigated.The ORSM based on PVK:40%(mass fraction)NNA composite film exhibited non-volatile and bipolar memory properties with a switching ratio(Ion/Ioff)of 24.1,endurance of 68 times and retention time of 104 s,a“SET”voltage(Vset)of−0.55 V and a“RESET”voltage(Vreset)of 2.35 V.The resistive switching was ascribed to the filling and vacant process of the charge traps induced by NNA and the inherent traps in PVK bulk.The holes trapping and de-trapping process occurred when the device was applied with a negative or positive bias,which caused the transforming of the conductive way of charges,that is the resistive behaviors in the macroscopic.This study provides a promising platform for the fabrication of ORSM with high performance.
基金supported by the Natural Science Foundation of Chongqing City(Grant Nos.CSTB2022NSCQ-MSX0751 and cstc2021jcyj-msxmX0500)the Education Department Project of Jilin Province(Grant No.JJKH20220726KJ)+1 种基金the Science and Technology Department Project of Jilin Province(Grant No.20200201077JC)the National Natural Science Foundation of China(Grant No.U2141239).
文摘The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.
文摘PVA(1-x)PSx (x = 0.0, 0.25, 0.50, 0.75 and 1.0) polymer blend films were prepared by simple solution cast method using mixer of dimethyl sulphoxide (DMSO) and double distilled water (DDW) as a common solvent. Gamma irradiation studies have been carried out to investigate the potential for improvements in the electrical properties of pure and blend polymer film. The induced changes in the dielectric constant (εr), dielectric loss (tanδ) and AC conductivity (σac) properties for the unirradiated and irradiated films were studied, in the frequency range 50 Hz - 5 MHz at room temperature (27°C). Further, it was seen that the frequency dependent dielectric constant, dielectric loss and AC conductivity were found to increase with increasing γ irradiation dose for all the PVA(1-x)PSx (x = 0.0, 0.25, 0.50, 0.75 and 1.0) polymer blends. The maximum σac at 1 kHz frequency was observed to be 2.4421 × 10-6 s/m (at room temperature) for PVA film irradiated at 1.5 kGy.
基金This work was financially supported by the Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shen-zhen Park Project(No.HZQB-KCZYB-2020030)the RGC Gen-eral Research Fund(No.AoE/M-402/20,CityU 11209918)+1 种基金the RGC Theme-based Research Scheme(No.T13-402/17-N)the Ma-jor Program of Changsha Science and Technology Project(No.kh2003023).
文摘Achieving high strength,deformability and toughness in polymers is important for practical industrial applications.This has remained challenging because of the mutually opposing effects of improvements to each of these properties.Here,a self-assembling nacre-like polymer composite is designed to achieve ex-tremely tough with increasing strength.This special design significantly improved polymer’s mechanical properties,including an ultra-high fracture strain of 1180%,a tensile strength of 55.4 MPa and a toughness of 506.9 MJ/m^(3),which far exceed the highest values previously reported for polymer composites.This ex-cellent combination of properties can be attributed to a novel toughening mechanism,achieved by the synergy of the domain-limiting effect of metallic glass fragments with the strain-gradient-induced orien-tation and crystallisation within the polymer during stretching.Our approach opens a promising avenue for designing robust polymer materials in armour and aerospace engineering for a range of innovative applications.
基金Project(5227010679)supported by the National Natural Science Foundation of China。
文摘The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.
基金Supported by National Natural Science Foundation of China (50741003)Key Project of Science and Technology of Ministry of Education of China (107066)Anhui Provincial Natural Science Foundation (070414181)
