On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient ...On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient and eco-friendly process,mild conditions,and simple post-treatment.The experimental results reveal that a homogeneous deposited film(Cu NCs/CCS nanocomposite film)is generated on the Cu plate(the anode)after electrodeposition,which exhibits an obvious red florescence.The results from TEM observation suggest there are nanoparticles(with the average particle size of 2.3 nm)in the deposited film.Spectral analysis results both demonstrate the existence of Cu NCs in the deposited film.Moreover,the Cu NCs/CCS film modified electrode is directly created through electrodeposition of CCS,which enables promising application in the electrochemical sensing.By means of fluorescence properties of Cu NCs,the Cu NCs/CCS film also owns the potential in fluorescence detection.Therefore,this work builds a novel method for the green synthesis of Cu NCs,meanwhile it offers a convenient and new electrodeposition strategy to prepare polysaccharide-based Cu NCs nanocomposites for uses in functional nanocomposites and bioelectronic devices.展开更多
Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and super...Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and superparamagnetic properties.When the substrate temperature increases from room temperature to 400℃,Co particles gradually grow,and the degree of Co oxidation significantly decreases.Consequently,the saturation magnetization increases from 0.13 to 0.43 T at the same Co content by increasing the substrate temperature from room temperature to 400℃.At a high substrate temperature,conductive pathways form among some of the clustered Co particles.Thus,resistivity rapidly declines from 1600 to 76μΩ·m.The magnetoresistive characteristic of Co−TiO2 films is achieved even at resistivity of as low as 76μΩ·m.These results reveal that the obtained nanocomposite films have low Co oxidation,high magnetization and magnetoresistance at room temperature.展开更多
A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an impl...A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an implantation dose of 3 × 10^15 atoms.cm-2 and then annealed in air at 450℃ for 2 h. The morphology was observed by scanning electron microscopy. The microstructure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic degradation of methylene blue solution was carried out under ultraviolet light. The corrosion resistance of the stainless steel was evaluated in NaCl solution （3.5 wt%） by electrochemical polarization curves. It is found that the Ti ions depth profile resembles a Gaussian distribution in the implanted layer. The nanostructured Fe203/TiO2 composite film exhibits a remarkable enhancement in photocatalytic activity referenced to the mechanically polished specimen and anodized specimen. Meanwhile, the annealed Ti-implanted specimen remains good corrosion resistance.展开更多
The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS）...The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.展开更多
Carboxymethylated cellulose nanofibril(CMCNF)is an effective green dispersant to prepare well-dispersed monolayer montmorillonites(MMTs)in water,thereby facilitating the preparation of a high-performance MMT/polymer n...Carboxymethylated cellulose nanofibril(CMCNF)is an effective green dispersant to prepare well-dispersed monolayer montmorillonites(MMTs)in water,thereby facilitating the preparation of a high-performance MMT/polymer nanocomposite film.However,not enough attention has been paid to correlating the degree of substitution(DS)of CMCNFs with the mechanical and optical properties of the final nanocomposite films.In this study,a series of homogeneous monolayer MMT nanoplatelet dispersions was prepared initially using CMCNFs with different DS as a dispersant,and the as-prepared CMCNF-dispersed MMT dispersions were then mixed with sodium carboxymethyl cellulose(CMC-Na)to fabricate nacre-like nanocomposite films with different contents of MMTs through self-assembly.The layered nanostructure and optical and mechanical properties of the asprepared CMCNF-dispersed MMT/CMC-Na nanocomposite films were investigated,which demonstrated that CMCNFs with lower DS have a positive effect on their optical and mechanical properties.This study sheds light on the preparation of MMT-based nanocomposite films with superior optical and mechanical properties.展开更多
The nanocomposite films were prepared by direct intercalation of poly(ethylene oxide) and PEO into MoO 3 xerogel via sol-gel route.The electrochromic behavior and the chemical conditions of Li + ions were investigat...The nanocomposite films were prepared by direct intercalation of poly(ethylene oxide) and PEO into MoO 3 xerogel via sol-gel route.The electrochromic behavior and the chemical conditions of Li + ions were investigated by cyclic voltammograms,UV-visible spectral transmittance and XPS.The results show that the cycling efficiency and the reversibility of insertion/extraction of Li + ions in (PEO) 1MoO 3·nH 2O nanocomposite film were improved.The intercalation of PEO into MoO 3 xerogel modulated the wavelength range of electrochromism and enhanced the electrochromic efficiency.Two different chemical conditions of Li + ions existing in the interlayer and interstitial positions of MoO 3 lattice were observed in MoO 3 xerogel and (PEO) 1MoO 3·nH 2O nanocomposite films.展开更多
Tensile deformation and fracture characteristics of polyimide/montmorillonite nanocomposite films are investigated to enhance the particular mechanical properties and understand the effective factors in dominating the...Tensile deformation and fracture characteristics of polyimide/montmorillonite nanocomposite films are investigated to enhance the particular mechanical properties and understand the effective factors in dominating the mechanical properties of nanocomposites, such as the nanolayer, matrix and nanolayer/matrix interface. How to contribute to the mechanical properties of nanocomposite film is a very complex problem. In this paper, these factors are analyzed based on the addition amount and fracture mechanics. The results indicate that the specimen at 20 wt% MMT breaks prematurely with a fracture strength （σb = 78 MPa） much lower than that （σb = 128 MPa） at the 1 wt% MMT. However, the Young＇s modulus （3.2 GPa） of the former is higher than that （1.9 GPa） of the latter. Fractography also indicates that the brittle cracking formed in high content addition is the main cause of failure but microscopically ductile fracture morphology still exists locally. And for the trace element addition, the smaller threading slipping veins are evenly distributed on the entire fracture section of these films. Therefore, these characteristics would presumably be associated with both the concentration effects of size of nanocomposite sheets and the increasing deformation harmony in nanolayers.展开更多
In this paper analysis of constant-intensity approximation of nonlinear interaction of the second-harmonic generation in ZnO/PMMA nanocomposite films for different concentrations of ZnO was carried out with regard to ...In this paper analysis of constant-intensity approximation of nonlinear interaction of the second-harmonic generation in ZnO/PMMA nanocomposite films for different concentrations of ZnO was carried out with regard to the losses and phase changes of all the interacting waves. The investigated samples were manufactured on the basis of ZnO nanoparticles embedded into polyvinylchloride polymeric matrix （PMMA） by the method of electrochemical deposition. The main goal of work is the exploration of the ZnO morphology and parameters of the second order susceptibilities. It is verified that the surface effects in ZnO/PMMA structures will give a larger contribution than the volume effects. The factors restricting the efficiency of the process of frequency conversion have been analyzed.展开更多
To impart polymers with high electrical conductivity and satisfactory electromagnetic interference shielding efficiency,it is crucial to efficiently construct interconnecting networks of conductive nanofillers in poly...To impart polymers with high electrical conductivity and satisfactory electromagnetic interference shielding efficiency,it is crucial to efficiently construct interconnecting networks of conductive nanofillers in polymer matrices.Herein,on the basis of the three-dimensional(3D)skeleton and volume-exclusion effect of silane-modified tetra-needle ZnO(ST-ZnO)whiskers and the high conductivity of two-dimensional MXene nanosheets,multifunctional MXene/ST-ZnO/waterborne polyurethane(MTW)nanocomposite films are fabricated by coating of MXene on ST-ZnO followed by compounding with waterborne polyurethane.The 3D four-needles of the whiskers facilitate the formation of an interconnecting network in the waterborne polyurethane matrix,while the coating of MXene efficiently makes the interconnecting network of the whiskers conductive at a low amount of the MXene.The resultant MTW ternary nanocomposite film exhibits not only a high electrical conductivity of 4.8×10^(4)S/m,but also an excellent electromagnetic interference shielding effectiveness of over 70 dB in the X-band at a low thickness of 100µm.In addition,the ternary film also exhibits outstanding Joule heating performances with an equilibrium temperature of 113℃at a low driving voltage of 3 V.The multifunctional nanocomposite films are promising for applications in portable and wearable electronics and flexible electromagnetic interference shielding devices.展开更多
Designing super-broadband transparent conductors is challenging because of the exclusive nature of conductivity and infrared transmittance.Here,using a one-step process,we created vertically aligned nanocomposite cond...Designing super-broadband transparent conductors is challenging because of the exclusive nature of conductivity and infrared transmittance.Here,using a one-step process,we created vertically aligned nanocomposite conducting films with high transparency across a super-broad wavelength range.Vertically aligned transparent Ba_(3)V_(2)O_(8)nanocolumns with lateral-100-nm widths enable high transmittance(>50%,even at a 4-μm wavelength)for all incident light and outperform that of Sn-doped In_(2)O_(3),while the conducting SrVO_(3)matrix retains low resistivity(<0.56 mΩcm at room temperature).A combined study of scanning transmission electron microscopy,scattering scanning nearfield infrared microscopy,and X-ray diffraction revealed that spontaneous phase separation of Ba_(3)V_(2)O_(8)nanocolumns in a SrVO_(3)matrix film occurs via self-assembled epitaxial nucleation.Our vertically aligned nanocomposite films provide a fertile platform for next-generation optoelectronics.展开更多
nc-Ti C/a-C：H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C_2H_2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray ph...nc-Ti C/a-C：H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C_2H_2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray photoelectron spectroscopy（XPS）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）,Raman spectroscopy, nanoindentation, and ball-on-disc tribometry. The films show a nanocomposite structure in which Ti C crystallites are embedded in the amorphous matrix of a-C：H phase. C content in films increases with the flow ratio of C_2H_2/Ar, simultaneously, the crystallite size of TiC decreases. Contrary to the nc-Ti C/a-C：H films deposited by magnetron sputtering in which the sp3 C content increases with C_2H_2 flow rate, the increase of C_2H_2 flow rate leads to the increase of sp2 C content in films deposited by filtered cathodic arc technique. The nc-Ti C/a-C：H films deposited by cathodic arc technique have a pronounced hardness maximum of 30 GPa under the C_2H_2/Ar flow ratio of 12. Tribological performance of films is controlled by the sp2 content in films. Higher sp2 content promotes the formation of graphite-like transfer layer during sliding,and results in lower wear rate and friction coefficient.展开更多
A Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite film with high performance of photogenerated cathodic protection was prepared by hydrothermal and photoreduction methods.The results showed that when the CuFe_(2)O_(4) hydrothe...A Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite film with high performance of photogenerated cathodic protection was prepared by hydrothermal and photoreduction methods.The results showed that when the CuFe_(2)O_(4) hydrothermal reaction time was 6 h and the AgNO_(3) concentration was 0.1 M,the Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite material performed the best cathodic protection capability for 304 stainless steel(304SS).In this case,the protective potential achieved-930 mV(versus SCE)associated with the photocurrent density of 475μA/cm^(2),which was 14.8 times that of pure TiO_(2) nanowires.In the dark,the nanocomposite provided cathodic protection of up to 485 mV for 304SS.Due to the heterogeneous junctions at the two interfaces among the three kinds of nanocomposite materials,the build-in electric field was fabricated,which promoted the separation efficiency of photogenerated electrons and holes and effectively improved the photochemical cathodic protection of 304SS.展开更多
A new technique to synthesize poly（diphenylsilylenemethylene） （PDPhSM） matrix nanocomposite thin films containing metal nanoparticles such as Ni, AI, Zn, and W produced by pulsed laser ablation has been developed....A new technique to synthesize poly（diphenylsilylenemethylene） （PDPhSM） matrix nanocomposite thin films containing metal nanoparticles such as Ni, AI, Zn, and W produced by pulsed laser ablation has been developed. First, 1,1,3,3-tetra- phenyl-1,3-disilacyclobutane （TPDC） films were deposited on 4 cm2 silicon substrates cut from c-Si wafers by conventional vacuum evaporation under a pressure of 4.0×10^-3 Pa; then metal nanoparticles were deposited onto the TPDC films by pulsed laser ablation; finally the TPDC films with metal nanoparticles were heated in an electric furnace in an air atmosphere at 553 K for 10 rain to induce ring-opening polymerization of TPDC. The results indicate that it is easy to synthesize metal/ PDPhSM nanocomposite thin films by pulsed laser ablation. The morphologies and size of metal nanoparticles are closely related to the kinds of metal. Also, the polymerization efficiency depends on the kinds of metal nanoparticles deposited on the TPDC monomer films by pulsed laser ablation. In addition, The laser ablated metal nanoparticles penetrate into the TPDC monomer films during pulsed laser ablation while the DC sputtered metal nanoparticles just lay on the surface of TPDC films.展开更多
Polyaniline/indium oxide （PANI/In2O3） nanocomposite thin films have been prepared in water-dispersed medium with the presence of different surfactants by an in-situ self-assembly technique. A cationic surfactant TT...Polyaniline/indium oxide （PANI/In2O3） nanocomposite thin films have been prepared in water-dispersed medium with the presence of different surfactants by an in-situ self-assembly technique. A cationic surfactant TTAB （tetradecyltrimethyl-ammonium bromide） and a non-ionic surfactant tween-20 （poly （ethylene oxide） （20） sorbitan monolaurate） are used as additives. The nanocomposites and thin films are characterized by Fourier transform infrared （FTIR）, transmission electron microscopy （TEM）, and scanning electron microscopy （SEM）, respectively. The optical properties reveal the interaction between PANI/In2O3 nanocomposites and surfactants, and PANI/In2O3 thin films prepared in the presence of surfactants exhibits the finer nanofiber than the surfactants free PANI/In2O3 thin film. The ammonia （NH3） gas-sensing characteristic of PANI/In2O3 thin films and the effect of different surfactants on the gas-sensing property are studied. The results indicated that the film processed in the presence of TTAB has the highest gas sensitivity among all the prepared films.展开更多
A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characteri...A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characterized by transmission electron micrograph （TEM）, ultraviolet-visible absorption spectra （UV-Vis） and fluorescence spectra （FS）. It was found that the fluorescence intensity of methyl orange （MO） was enhanced by 5 times in the aqueous composite system doped with silver nanoparticles whereas it was reduced by 15% and 20% in composite films with co-mixing and coating structures, respectively. The results indicate that the properties of functional molecules can be greatly improved in composite film with supra molecular structure and that the procedure presented here is effective.展开更多
The Ni-TiN nanocomposite film was successfully electrodeposited on brass copper substrates.The microstructures of the Ni-TiN nanocomposite film were investigated using scanning electron microscopy（SEM） and transmiss...The Ni-TiN nanocomposite film was successfully electrodeposited on brass copper substrates.The microstructures of the Ni-TiN nanocomposite film were investigated using scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.Its average grain size was analyzed through X-ray diffraction（XRD）,and its anti-corrosion property was studied through potentiodynamic scanning curves and electrochemical impedance spectroscopy（EIS）.The results show that the morphology of Ni-TiN composite film is sensitively dependent on the electroplating current density,TiN nanoparticle concentration,solution stirring speed,bath temperature and pH value of solution.The average grain size of the optimized nanocomposite film is about 50 nm.Meanwhile,the Ni-TiN nanocomposite films are much more resistant to corrosion than pure Ni coatings.展开更多
Nanocomposite films based on poly (3,4-ethylenedioxy thiophene) (PEDOT), functionalized single-walled carbon nanotubes and different dopants were studied. It was fabricated by a simple oxidative electropolymerization ...Nanocomposite films based on poly (3,4-ethylenedioxy thiophene) (PEDOT), functionalized single-walled carbon nanotubes and different dopants were studied. It was fabricated by a simple oxidative electropolymerization method. The dopant substances used were SDS (Sodium dodecyl sulfate) and tiron (1,2-Dihydroxybenzene-3,5-disulfonic acid disodium salt hydrate). These nano-composite films were grown electrochemically from aqueous solutions such that constituents were deposited simultaneously onto substrate electrode. The synthetic, morphological and electrical properties of the nanocomposite films obtained were compared. Scanning electron microscopy (SEM) revealed that the composite films consisted of nanoporous networks of SWCNTS (single-walled carbon nanotubes) coated with polymeric film. Cyclic voltammetry (CV), electro-chemical impedance spectroscopy (EIS) and FT-IR spectroscopy demonstrated that these composite films had similar electrochemical response rates to pure polymeric films but a lower resistance and much improved mechanical integrity. The negatively charged functionalized carbon nano-tubes (CNTSF) served as anionic dopant during the electropolymerization to synthesize polymer/CNTSF composite films. The specific electrochemical capacitance of the composite films is a significantly higher value than that for pure polymer films prepared similarly. Using these composite films, the modified electrodes with improved properties were obtained. (In this paper, for simplicity, the SWANTs-COOH group will be noted CNTsF which means functionalized carbon nanotubes.)展开更多
Lightweight,high-efficiency and low reflection electromagnetic interference(EMI)shielding polymer composites are greatly desired for addressing the challenge of ever-increasing electromagnetic pollution.Lightweight la...Lightweight,high-efficiency and low reflection electromagnetic interference(EMI)shielding polymer composites are greatly desired for addressing the challenge of ever-increasing electromagnetic pollution.Lightweight layered foam/film PVDF nanocomposites with efficient EMI shielding effectiveness and ultralow reflection power were fabricated by physical foaming.The unique layered foam/film structure was composed of PVDF/SiCnw/MXene(Ti_(3)C_(2)Tx)composite foam as absorption layer and highly conductive PVDF/MWCNT/GnPs composite film as a reflection layer.The foam layer with numerous heterogeneous interfaces developed between the SiC nanowires(SiCnw)and 2D MXene nanosheets imparted superior EM wave attenuation capability.Furthermore,the microcellular structure effectively tuned the impedance matching and prolonged the wave propagating path by internal scattering and multiple reflections.Meanwhile,the highly conductive PVDF/MWCNT/GnPs composite(~220 S m^(−1))exhibited superior reflectivity(R)of 0.95.The tailored structure in the layered foam/film PVDF nanocomposite exhibited an EMI SE of 32.6 dB and a low reflection bandwidth of 4 GHz(R<0.1)over the Kuband(12.4-18.0 GHz)at a thickness of 1.95 mm.A peak SER of 3.1×10^(-4) dB was obtained which corresponds to only 0.0022% reflection efficiency.In consequence,this study introduces a feasible approach to develop lightweight,high-efficiency EMI shielding materials with ultralow reflection for emerging applications.展开更多
A new thermal ring-opening polymerization technique for 1, 1, 3, 3-tetra-ph enyl-1, 3-disilacyclobutane （TPDC） based on the use of metal nanoparticles produced by pulsed laser ablation was investigated. This method ...A new thermal ring-opening polymerization technique for 1, 1, 3, 3-tetra-ph enyl-1, 3-disilacyclobutane （TPDC） based on the use of metal nanoparticles produced by pulsed laser ablation was investigated. This method facilitates the synthesis of polydiphenysilylenemethyle （PDPhSM） thin film, which is difficult to make by conventional methods because of its insolubility and high melting point. TPDC was first evaporated on silicon substrates and then exposed to metal nanoparticles deposition by pulsed laser ablation prior to heat treatment.The TPDC films with metal nanoparticles were heated in an electric furnace in air atmosphere to induce ring-opening polymerization of TPDC. The film thicknesses before and after polymerization were measured by a stylus profilometer. Since the polymerization process competes with re-evaporation of TPDC during the heating, the thickness ratio of the polymer to the monomer was defined as the polymerization efficiency, which depends greatly on the technology conditions. Therefore, a well trained radial base function neural network model was constructed to approach the complex nonlinear relationship. Moreover, a particle swarm algorithm was firstly introduced to search for an optimum technology directly from RBF neural network model. This ensures that the fabrication of thin film with appropriate properties using pulsed laser ablation requires no in-depth understanding of the entire behavior of the technology conditions.展开更多
Imparting electro-conductive properties to nanocellulose-based products may render them suitable for applications in electronics, optoelectronics, and energy storage devices. In the present work, an electro...Imparting electro-conductive properties to nanocellulose-based products may render them suitable for applications in electronics, optoelectronics, and energy storage devices. In the present work, an electro-conductive nanocrystalline cellulose （NCC） film filled with TiO2-reduced-graphene oxide （TiO2-RGO） was developed. Initially, graphene oxide （GO） was prepared using the modified Hummers method and thereafter photocatalytically reduced using TiO2 as a catalyst. Subsequently, an electro-conductive NCC film was prepared via vacuum filtration with the as-prepared TiO2-RGO nanocomposite as a functional filler. The TiO2-RGO nanocomposite and the NCC/TiO2-RGO film were systematically characterized. The results showed that the obtained TiO2-RGO nanocomposite exhibited reduced oxygen-containing group content and enhanced electro-conductivity as compared with those of GO. Moreover, the NCC flm flled with TiO2-RGO nanocomposite displayed an electro-conductivity of up to 9.3 S/m and improved mechanical properties compared with that of the control. This work could provide a route for producing electro-conductive NCC flms, which may hold signifcant potential as transparent ？exible substrates for future electronic device applications.展开更多
基金Funded by the National Natural Science Foundation of China(No.51873167)the Fundamental Research Funds for the Central Universities(WUT:2022-CL-A1-04)。
文摘On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient and eco-friendly process,mild conditions,and simple post-treatment.The experimental results reveal that a homogeneous deposited film(Cu NCs/CCS nanocomposite film)is generated on the Cu plate(the anode)after electrodeposition,which exhibits an obvious red florescence.The results from TEM observation suggest there are nanoparticles(with the average particle size of 2.3 nm)in the deposited film.Spectral analysis results both demonstrate the existence of Cu NCs in the deposited film.Moreover,the Cu NCs/CCS film modified electrode is directly created through electrodeposition of CCS,which enables promising application in the electrochemical sensing.By means of fluorescence properties of Cu NCs,the Cu NCs/CCS film also owns the potential in fluorescence detection.Therefore,this work builds a novel method for the green synthesis of Cu NCs,meanwhile it offers a convenient and new electrodeposition strategy to prepare polysaccharide-based Cu NCs nanocomposites for uses in functional nanocomposites and bioelectronic devices.
基金Project(2016YFE0205700)supported by the National Key Research and Development Program of ChinaProject(18JCYBJC18000)supported by the Natural Science Foundation of Tianjin City,China。
文摘Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and superparamagnetic properties.When the substrate temperature increases from room temperature to 400℃,Co particles gradually grow,and the degree of Co oxidation significantly decreases.Consequently,the saturation magnetization increases from 0.13 to 0.43 T at the same Co content by increasing the substrate temperature from room temperature to 400℃.At a high substrate temperature,conductive pathways form among some of the clustered Co particles.Thus,resistivity rapidly declines from 1600 to 76μΩ·m.The magnetoresistive characteristic of Co−TiO2 films is achieved even at resistivity of as low as 76μΩ·m.These results reveal that the obtained nanocomposite films have low Co oxidation,high magnetization and magnetoresistance at room temperature.
基金financially supported by the National Natural Science Foundation of China (Nos. 50771075 and51171133)the Program for New Century Excellent Talents in Universities (No. NCET-07-0650)The Cooperation Project in Industry,Education and Research of Guangdong Province and the Ministry of Education of China (No. 2011B090400334)
文摘A simple surface treatment was used to develop photocatalytic activity for stainless steel. AISI 304 stainless steel specimens after anodization were implanted by Ti ions at an extracting voltage of 50 kV with an implantation dose of 3 × 10^15 atoms.cm-2 and then annealed in air at 450℃ for 2 h. The morphology was observed by scanning electron microscopy. The microstructure was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic degradation of methylene blue solution was carried out under ultraviolet light. The corrosion resistance of the stainless steel was evaluated in NaCl solution （3.5 wt%） by electrochemical polarization curves. It is found that the Ti ions depth profile resembles a Gaussian distribution in the implanted layer. The nanostructured Fe203/TiO2 composite film exhibits a remarkable enhancement in photocatalytic activity referenced to the mechanically polished specimen and anodized specimen. Meanwhile, the annealed Ti-implanted specimen remains good corrosion resistance.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51337002,51077028,51502063 and 51307046the Foundation of Harbin Science and Technology Bureau of Heilongjiang Province under Grant No RC2014QN017034
文摘The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.
基金We would like to thank for the financial support from the National Natural Science Foundation of China(21978103)the Natural Science Foundation of Guangdong Province(2020B1515020021)+2 种基金the Pearl River S&T Nova Program of Guangzhou(201806010141)the Foundation of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education/Shandong Province of China(KF201812)the Fundamental Research Funds for the Central Universities(2019MS083).
文摘Carboxymethylated cellulose nanofibril(CMCNF)is an effective green dispersant to prepare well-dispersed monolayer montmorillonites(MMTs)in water,thereby facilitating the preparation of a high-performance MMT/polymer nanocomposite film.However,not enough attention has been paid to correlating the degree of substitution(DS)of CMCNFs with the mechanical and optical properties of the final nanocomposite films.In this study,a series of homogeneous monolayer MMT nanoplatelet dispersions was prepared initially using CMCNFs with different DS as a dispersant,and the as-prepared CMCNF-dispersed MMT dispersions were then mixed with sodium carboxymethyl cellulose(CMC-Na)to fabricate nacre-like nanocomposite films with different contents of MMTs through self-assembly.The layered nanostructure and optical and mechanical properties of the asprepared CMCNF-dispersed MMT/CMC-Na nanocomposite films were investigated,which demonstrated that CMCNFs with lower DS have a positive effect on their optical and mechanical properties.This study sheds light on the preparation of MMT-based nanocomposite films with superior optical and mechanical properties.
文摘The nanocomposite films were prepared by direct intercalation of poly(ethylene oxide) and PEO into MoO 3 xerogel via sol-gel route.The electrochromic behavior and the chemical conditions of Li + ions were investigated by cyclic voltammograms,UV-visible spectral transmittance and XPS.The results show that the cycling efficiency and the reversibility of insertion/extraction of Li + ions in (PEO) 1MoO 3·nH 2O nanocomposite film were improved.The intercalation of PEO into MoO 3 xerogel modulated the wavelength range of electrochromism and enhanced the electrochromic efficiency.Two different chemical conditions of Li + ions existing in the interlayer and interstitial positions of MoO 3 lattice were observed in MoO 3 xerogel and (PEO) 1MoO 3·nH 2O nanocomposite films.
基金Project supported by the National Basic Research Program of China (No.2004CB619304)the Hundred TalentsProgram of Chinese Academy of Sciences, Key Research Programme of Beijing City Science and Technology Committee(No.H020420020230).
文摘Tensile deformation and fracture characteristics of polyimide/montmorillonite nanocomposite films are investigated to enhance the particular mechanical properties and understand the effective factors in dominating the mechanical properties of nanocomposites, such as the nanolayer, matrix and nanolayer/matrix interface. How to contribute to the mechanical properties of nanocomposite film is a very complex problem. In this paper, these factors are analyzed based on the addition amount and fracture mechanics. The results indicate that the specimen at 20 wt% MMT breaks prematurely with a fracture strength （σb = 78 MPa） much lower than that （σb = 128 MPa） at the 1 wt% MMT. However, the Young＇s modulus （3.2 GPa） of the former is higher than that （1.9 GPa） of the latter. Fractography also indicates that the brittle cracking formed in high content addition is the main cause of failure but microscopically ductile fracture morphology still exists locally. And for the trace element addition, the smaller threading slipping veins are evenly distributed on the entire fracture section of these films. Therefore, these characteristics would presumably be associated with both the concentration effects of size of nanocomposite sheets and the increasing deformation harmony in nanolayers.
文摘In this paper analysis of constant-intensity approximation of nonlinear interaction of the second-harmonic generation in ZnO/PMMA nanocomposite films for different concentrations of ZnO was carried out with regard to the losses and phase changes of all the interacting waves. The investigated samples were manufactured on the basis of ZnO nanoparticles embedded into polyvinylchloride polymeric matrix （PMMA） by the method of electrochemical deposition. The main goal of work is the exploration of the ZnO morphology and parameters of the second order susceptibilities. It is verified that the surface effects in ZnO/PMMA structures will give a larger contribution than the volume effects. The factors restricting the efficiency of the process of frequency conversion have been analyzed.
基金the National Natural Science Foundation of China(Nos.51922020 and 52090034)the Fundamental Research Funds for the Central Universities(Nos.BHYC1707B and XK1802-2).
文摘To impart polymers with high electrical conductivity and satisfactory electromagnetic interference shielding efficiency,it is crucial to efficiently construct interconnecting networks of conductive nanofillers in polymer matrices.Herein,on the basis of the three-dimensional(3D)skeleton and volume-exclusion effect of silane-modified tetra-needle ZnO(ST-ZnO)whiskers and the high conductivity of two-dimensional MXene nanosheets,multifunctional MXene/ST-ZnO/waterborne polyurethane(MTW)nanocomposite films are fabricated by coating of MXene on ST-ZnO followed by compounding with waterborne polyurethane.The 3D four-needles of the whiskers facilitate the formation of an interconnecting network in the waterborne polyurethane matrix,while the coating of MXene efficiently makes the interconnecting network of the whiskers conductive at a low amount of the MXene.The resultant MTW ternary nanocomposite film exhibits not only a high electrical conductivity of 4.8×10^(4)S/m,but also an excellent electromagnetic interference shielding effectiveness of over 70 dB in the X-band at a low thickness of 100µm.In addition,the ternary film also exhibits outstanding Joule heating performances with an equilibrium temperature of 113℃at a low driving voltage of 3 V.The multifunctional nanocomposite films are promising for applications in portable and wearable electronics and flexible electromagnetic interference shielding devices.
基金supported by the national R&D programs through the National Research Foundation of Korea funded by the Ministry of Science and ICT(Project Nos.:NRF-2021M3F3A2A03015439,NRF-2021R1C1C1005042,and NRF-2018R1A5A1025511)We also acknowledge partial support from the national R&D programs through the National Research Foundation of Korea funded by the Ministry of Education(Project No.:NRF-2021R1A6A3A13043948)+1 种基金the DGIST R&D program of the Ministry of Science and ICT of Korea(Project Nos.:22-HRHR+-05,22-CoE-NT-02,and 22-SENS-1)Judith L.MacManus-Driscoll thanks the EU-H2020-ERC-ADG#882929 EROS grant for support,and the Royal Academy of Engineering-grant CIET1819_24.
文摘Designing super-broadband transparent conductors is challenging because of the exclusive nature of conductivity and infrared transmittance.Here,using a one-step process,we created vertically aligned nanocomposite conducting films with high transparency across a super-broad wavelength range.Vertically aligned transparent Ba_(3)V_(2)O_(8)nanocolumns with lateral-100-nm widths enable high transmittance(>50%,even at a 4-μm wavelength)for all incident light and outperform that of Sn-doped In_(2)O_(3),while the conducting SrVO_(3)matrix retains low resistivity(<0.56 mΩcm at room temperature).A combined study of scanning transmission electron microscopy,scattering scanning nearfield infrared microscopy,and X-ray diffraction revealed that spontaneous phase separation of Ba_(3)V_(2)O_(8)nanocolumns in a SrVO_(3)matrix film occurs via self-assembled epitaxial nucleation.Our vertically aligned nanocomposite films provide a fertile platform for next-generation optoelectronics.
基金financially supported by the Ministry of Science and Technology of China(973 Plan)(No2013CB632303)the National Natural Science Foundation of China(Nos.51001084 and 51275154)
文摘nc-Ti C/a-C：H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C_2H_2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray photoelectron spectroscopy（XPS）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）,Raman spectroscopy, nanoindentation, and ball-on-disc tribometry. The films show a nanocomposite structure in which Ti C crystallites are embedded in the amorphous matrix of a-C：H phase. C content in films increases with the flow ratio of C_2H_2/Ar, simultaneously, the crystallite size of TiC decreases. Contrary to the nc-Ti C/a-C：H films deposited by magnetron sputtering in which the sp3 C content increases with C_2H_2 flow rate, the increase of C_2H_2 flow rate leads to the increase of sp2 C content in films deposited by filtered cathodic arc technique. The nc-Ti C/a-C：H films deposited by cathodic arc technique have a pronounced hardness maximum of 30 GPa under the C_2H_2/Ar flow ratio of 12. Tribological performance of films is controlled by the sp2 content in films. Higher sp2 content promotes the formation of graphite-like transfer layer during sliding,and results in lower wear rate and friction coefficient.
基金financially supported by the National Natural Science Foundation of China(Nos.U1706225,42006046,2019GGX102014,2019YFC0312103)the Research Fund of Open Studio for Marine Corrosion and Protection,Pilot National Laboratory for Marine Science and Technology(Qingdao,No.HYFSKF201804)。
文摘A Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite film with high performance of photogenerated cathodic protection was prepared by hydrothermal and photoreduction methods.The results showed that when the CuFe_(2)O_(4) hydrothermal reaction time was 6 h and the AgNO_(3) concentration was 0.1 M,the Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite material performed the best cathodic protection capability for 304 stainless steel(304SS).In this case,the protective potential achieved-930 mV(versus SCE)associated with the photocurrent density of 475μA/cm^(2),which was 14.8 times that of pure TiO_(2) nanowires.In the dark,the nanocomposite provided cathodic protection of up to 485 mV for 304SS.Due to the heterogeneous junctions at the two interfaces among the three kinds of nanocomposite materials,the build-in electric field was fabricated,which promoted the separation efficiency of photogenerated electrons and holes and effectively improved the photochemical cathodic protection of 304SS.
基金Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A new technique to synthesize poly（diphenylsilylenemethylene） （PDPhSM） matrix nanocomposite thin films containing metal nanoparticles such as Ni, AI, Zn, and W produced by pulsed laser ablation has been developed. First, 1,1,3,3-tetra- phenyl-1,3-disilacyclobutane （TPDC） films were deposited on 4 cm2 silicon substrates cut from c-Si wafers by conventional vacuum evaporation under a pressure of 4.0×10^-3 Pa; then metal nanoparticles were deposited onto the TPDC films by pulsed laser ablation; finally the TPDC films with metal nanoparticles were heated in an electric furnace in an air atmosphere at 553 K for 10 rain to induce ring-opening polymerization of TPDC. The results indicate that it is easy to synthesize metal/ PDPhSM nanocomposite thin films by pulsed laser ablation. The morphologies and size of metal nanoparticles are closely related to the kinds of metal. Also, the polymerization efficiency depends on the kinds of metal nanoparticles deposited on the TPDC monomer films by pulsed laser ablation. In addition, The laser ablated metal nanoparticles penetrate into the TPDC monomer films during pulsed laser ablation while the DC sputtered metal nanoparticles just lay on the surface of TPDC films.
基金supported by the National Natural Science Foundation of China under Grant No. 60736005China-Australian Cooperative Foundation under Grant No. 60425101-1
文摘Polyaniline/indium oxide （PANI/In2O3） nanocomposite thin films have been prepared in water-dispersed medium with the presence of different surfactants by an in-situ self-assembly technique. A cationic surfactant TTAB （tetradecyltrimethyl-ammonium bromide） and a non-ionic surfactant tween-20 （poly （ethylene oxide） （20） sorbitan monolaurate） are used as additives. The nanocomposites and thin films are characterized by Fourier transform infrared （FTIR）, transmission electron microscopy （TEM）, and scanning electron microscopy （SEM）, respectively. The optical properties reveal the interaction between PANI/In2O3 nanocomposites and surfactants, and PANI/In2O3 thin films prepared in the presence of surfactants exhibits the finer nanofiber than the surfactants free PANI/In2O3 thin film. The ammonia （NH3） gas-sensing characteristic of PANI/In2O3 thin films and the effect of different surfactants on the gas-sensing property are studied. The results indicated that the film processed in the presence of TTAB has the highest gas sensitivity among all the prepared films.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 50271038）the Key Research Project Foundation of Shaanxi Normal University of China （No. 200403） Specialized Research Fund for the Doctoral Program of Higher Education of China （No. 20050698017）.
文摘A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characterized by transmission electron micrograph （TEM）, ultraviolet-visible absorption spectra （UV-Vis） and fluorescence spectra （FS）. It was found that the fluorescence intensity of methyl orange （MO） was enhanced by 5 times in the aqueous composite system doped with silver nanoparticles whereas it was reduced by 15% and 20% in composite films with co-mixing and coating structures, respectively. The results indicate that the properties of functional molecules can be greatly improved in composite film with supra molecular structure and that the procedure presented here is effective.
基金Projects(50771092,21073162) supported by the National Natural Science Foundation of ChinaProject(2005DKA10400-Z15) supported by the Ministry of Science and Technology of China
文摘The Ni-TiN nanocomposite film was successfully electrodeposited on brass copper substrates.The microstructures of the Ni-TiN nanocomposite film were investigated using scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.Its average grain size was analyzed through X-ray diffraction（XRD）,and its anti-corrosion property was studied through potentiodynamic scanning curves and electrochemical impedance spectroscopy（EIS）.The results show that the morphology of Ni-TiN composite film is sensitively dependent on the electroplating current density,TiN nanoparticle concentration,solution stirring speed,bath temperature and pH value of solution.The average grain size of the optimized nanocomposite film is about 50 nm.Meanwhile,the Ni-TiN nanocomposite films are much more resistant to corrosion than pure Ni coatings.
基金Financial support from PN-II-ID-PCE-2008-2 contract number 596,code ID_716(The National University Research Council)is gratefully acknowledged.
文摘Nanocomposite films based on poly (3,4-ethylenedioxy thiophene) (PEDOT), functionalized single-walled carbon nanotubes and different dopants were studied. It was fabricated by a simple oxidative electropolymerization method. The dopant substances used were SDS (Sodium dodecyl sulfate) and tiron (1,2-Dihydroxybenzene-3,5-disulfonic acid disodium salt hydrate). These nano-composite films were grown electrochemically from aqueous solutions such that constituents were deposited simultaneously onto substrate electrode. The synthetic, morphological and electrical properties of the nanocomposite films obtained were compared. Scanning electron microscopy (SEM) revealed that the composite films consisted of nanoporous networks of SWCNTS (single-walled carbon nanotubes) coated with polymeric film. Cyclic voltammetry (CV), electro-chemical impedance spectroscopy (EIS) and FT-IR spectroscopy demonstrated that these composite films had similar electrochemical response rates to pure polymeric films but a lower resistance and much improved mechanical integrity. The negatively charged functionalized carbon nano-tubes (CNTSF) served as anionic dopant during the electropolymerization to synthesize polymer/CNTSF composite films. The specific electrochemical capacitance of the composite films is a significantly higher value than that for pure polymer films prepared similarly. Using these composite films, the modified electrodes with improved properties were obtained. (In this paper, for simplicity, the SWANTs-COOH group will be noted CNTsF which means functionalized carbon nanotubes.)
基金the financial support of NSERC(Discovery Grant RGPIN-2015-03985).
文摘Lightweight,high-efficiency and low reflection electromagnetic interference(EMI)shielding polymer composites are greatly desired for addressing the challenge of ever-increasing electromagnetic pollution.Lightweight layered foam/film PVDF nanocomposites with efficient EMI shielding effectiveness and ultralow reflection power were fabricated by physical foaming.The unique layered foam/film structure was composed of PVDF/SiCnw/MXene(Ti_(3)C_(2)Tx)composite foam as absorption layer and highly conductive PVDF/MWCNT/GnPs composite film as a reflection layer.The foam layer with numerous heterogeneous interfaces developed between the SiC nanowires(SiCnw)and 2D MXene nanosheets imparted superior EM wave attenuation capability.Furthermore,the microcellular structure effectively tuned the impedance matching and prolonged the wave propagating path by internal scattering and multiple reflections.Meanwhile,the highly conductive PVDF/MWCNT/GnPs composite(~220 S m^(−1))exhibited superior reflectivity(R)of 0.95.The tailored structure in the layered foam/film PVDF nanocomposite exhibited an EMI SE of 32.6 dB and a low reflection bandwidth of 4 GHz(R<0.1)over the Kuband(12.4-18.0 GHz)at a thickness of 1.95 mm.A peak SER of 3.1×10^(-4) dB was obtained which corresponds to only 0.0022% reflection efficiency.In consequence,this study introduces a feasible approach to develop lightweight,high-efficiency EMI shielding materials with ultralow reflection for emerging applications.
基金Funded by the Zhejiang Provincial Natural Science Foundation of China(No.R405031)Jiaxing Science Planning Project(2009 2007)the Educa-tion Department of Zhejiang Province (No.20051441)
文摘A new thermal ring-opening polymerization technique for 1, 1, 3, 3-tetra-ph enyl-1, 3-disilacyclobutane （TPDC） based on the use of metal nanoparticles produced by pulsed laser ablation was investigated. This method facilitates the synthesis of polydiphenysilylenemethyle （PDPhSM） thin film, which is difficult to make by conventional methods because of its insolubility and high melting point. TPDC was first evaporated on silicon substrates and then exposed to metal nanoparticles deposition by pulsed laser ablation prior to heat treatment.The TPDC films with metal nanoparticles were heated in an electric furnace in air atmosphere to induce ring-opening polymerization of TPDC. The film thicknesses before and after polymerization were measured by a stylus profilometer. Since the polymerization process competes with re-evaporation of TPDC during the heating, the thickness ratio of the polymer to the monomer was defined as the polymerization efficiency, which depends greatly on the technology conditions. Therefore, a well trained radial base function neural network model was constructed to approach the complex nonlinear relationship. Moreover, a particle swarm algorithm was firstly introduced to search for an optimum technology directly from RBF neural network model. This ensures that the fabrication of thin film with appropriate properties using pulsed laser ablation requires no in-depth understanding of the entire behavior of the technology conditions.
基金financially supported by the Zhejiang Provincial Natural Science Foundation of China (Grant No. LY14C160003, LQ16C160002)the National Natural Science Foundation of China (Grant No.31100442)+2 种基金the Public Projects of Zhejiang Province (Grant No. 2017C31059)Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology, Zhejiang Open Foundation of the Most Important Subjects (Grant No. 2016KF01)521 Talent Cultivation Program of Zhejiang Sci-Tech University (Grant No. 11110132521310)
文摘Imparting electro-conductive properties to nanocellulose-based products may render them suitable for applications in electronics, optoelectronics, and energy storage devices. In the present work, an electro-conductive nanocrystalline cellulose （NCC） film filled with TiO2-reduced-graphene oxide （TiO2-RGO） was developed. Initially, graphene oxide （GO） was prepared using the modified Hummers method and thereafter photocatalytically reduced using TiO2 as a catalyst. Subsequently, an electro-conductive NCC film was prepared via vacuum filtration with the as-prepared TiO2-RGO nanocomposite as a functional filler. The TiO2-RGO nanocomposite and the NCC/TiO2-RGO film were systematically characterized. The results showed that the obtained TiO2-RGO nanocomposite exhibited reduced oxygen-containing group content and enhanced electro-conductivity as compared with those of GO. Moreover, the NCC flm flled with TiO2-RGO nanocomposite displayed an electro-conductivity of up to 9.3 S/m and improved mechanical properties compared with that of the control. This work could provide a route for producing electro-conductive NCC flms, which may hold signifcant potential as transparent ？exible substrates for future electronic device applications.
