Photocatalytic activity of ferric oxide/titanium dioxide nanocomposite films on stainless steel fabricated by anodization and ion implantation

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.

Research of Trap and Electron Density Distributions in the Interface of Polyimide/Al2O3 Nanocomposite Films Based on IDC and 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.

Optical and Mechanical Properties of CMCNF-dispersed MMT/CMC-Na Nanocomposite Films: Influence of the Degree of Substitution of CMCNFs

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.

Lithium Insertion in Poly(ethylene oxide)/MoO_3 Xerogel Nanocomposite Films

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.

EFFECT OF MONTMORILLONITE ADDITION ON MECHANICAL CHARACTERIZATIONS OF POLYIMIDE NANOCOMPOSITE FILMS

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.

Multifunctional Waterborne Polyurethane Nanocomposite Films with Remarkable Electromagnetic Interference Shielding,Electrothermal and Solarthermal Performances

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.

Vertically aligned nanocomposite films by self-assembled epitaxial nucleation for super-broadband transparent conductors

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.

Structure and mechanical properties of nc-TiC/a-C:H nanocomposite films deposited by filtered cathodic arc technique

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.

Preparation of Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite films and its performance of photoelectrochemical cathodic protection

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.

Synthesis of Metal/Poly(diphenylsilylenemethylene) Nanocomposite Thin Films by Pulsed Laser Ablation

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.

Preparation of Surfactants Directed PANI/In_2O_3 Nanocomposite Thin Films and Its NH_3-Sensing Properties

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.

Nanocomposites Based on Conducting Polymers and Functionalized Carbon Nanotubes with Different Dopants Obtained by 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.)

Optimization of Laser Ablation Technology for PDPhSM Matrix Nanocomposite Thin Film by Artificial Neural Networks-particle Swarm Algorithm

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.

Layered Foam/Film Polymer Nanocomposites with Highly Efficient EMI Shielding Properties and Ultralow Reflection

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.

THE NANOCOMPOSITE FILM OF POLYMER INTERCALATION IN V_2O_5 XEROGEL

The nanocomposite films were prepared by poly(ethylene oxide), PEO, intercalation in V2O5 xero-gel in sol-gel. The synthesis and state of the films are investigated by the XRD, IR, SEM, etc. The results show that V2O5, xerogel is a layered structure which arranges in c-direction. The mterlayer distance of V2O5 xerogel increases remarkably when PEO is intercalated in V2O5 xero-gel interlayer. PEO has strong interaction with V2O5 host. The surface of the films is homogeneous without holes and cracks.

Thermal Characteristics of PVA-PANI-ZnS Nanocomposite Film Synthesized by Gamma Irradiation Method

Gamma irradiation is employed for in situ preparation of PVA-PANI-ZnS nanocomposite. The irradiation dose is varied from 10 to 40 kGy at 10 kGy intervals. The XRD result confirms the formation of crystalline phases corresponding to ZnS nanoparticles, PVA and PANI. Field emission scanning electron microscopy shows the formation of agglomerated PANI along the PVA backbone, within which the ZnS nanoparticles are dispersed.UV-visible spectroscopy is conducted to measure the transmittance spectra of samples revealing the electronic absorption characteristics of ZnS and PANI nanoparticles. Photo-acoustic（PA） setup is installed to investigate the thermal properties of samples. The PA spectroscopy indicates a high value of thermal diffusivity for samples due to the presence of ZnS and PANI nanoparticles. Moreover, at higher doses, the more polymerization and formation of PANI and ZnS nanoparticles result in enhancement of thermal diffusivity.

Biodegradable starch/poly(vinyl alcohol) film reinforced with titanium dioxide nanoparticles

Biodegradable starch/poly （vinyl alcohol）/nano-titanium dioxide （ST/PVA/nano-Ti02） nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of Ti02 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.

Near-perfect fidelity polarization-encoded multilayer optical data storage based on aligned gold nanorods

Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic techniques vastly en-hancing the feasibility of applying polarization channels,the data fidelity in reconstructed bits has been constrained by severe crosstalks occurring between varied polarization angles during data recording and reading process,which gravely hindered the utilization of this technique in practice.In this paper,we demonstrate an ultra-low crosstalk polarization-en-coding multilayer ODS technique for high-fidelity data recording and retrieving by utilizing a nanofibre-based nanocom-posite film involving highly aligned gold nanorods(GNRs).With parallelizing the gold nanorods in the recording medium,the information carrier configuration minimizes miswriting and misreading possibilities for information input and output,respectively,compared with its randomly self-assembled counterparts.The enhanced data accuracy has significantly im-proved the bit recall fidelity that is quantified by a correlation coefficient higher than 0.99.It is anticipated that the demon-strated technique can facilitate the development of multiplexing ODS for a greener future.

Non-enzymatic Glucose Biosensor Based on Cu/SWNTs Composite Film Fabricated by One-step Electrodeposition

Based on the adsorption of copper ions on single-walled carbon nanotubes（SWNTs） in electrolyte, Cu/SWNTs nanocomposite film was initially prepared on indium-doped tin oxide（ITO） substrate by one-step electrodeposition. This method may provide a versatile and facile pathway to fabricate other SWNTs-supported metal composite films. Electrochemical experiments revealed that the obtained Cu/SWNTs/ITO electrode offered an excellent electrocatalytic activity towards the oxidation of glucose and could be applied to the construction of non-enzymatic glucose biosensor. The linear range of the sensor was 1.0×10–6 to 6.0×10–4 mol/L and the response time was within 2 s. Particularly, its sensitivity reached as high as 1434.67 μA？L？mmol–1？cm–2, which was superior to any other non-enzymatic glucose biosensor based on copper-carbon nanotubes electrode reported previously.

Enhanced energy density in polyetherimide nanocomposite film at high temperature induced by electrospun BaZrTiO_(3) nanofibers

Polymer dielectrics which possess excellent dielectric properties such as high breakdown strength,flexibility,and facile processability are considered as promising materials for advanced electrostatic capacitors.However,most dielectric polymers have unsatisfactory energy storage performances at high-temperature environments.Here,polyetherimide(PEI) nanocomposite films contained with electrospun Ba(Zr_(0.79)Ti_(0.21))O_(3) nanofibers(BZTNFs) are fabricated by common solution casting method.The dielectric properties,especially the breakdown strength of the BZTNFs/PEI nanocomposites,are characterized,yet improvement is only in the small loading ones.The energy storage performance of the 0.5 vol% and1.0 vol% BZTNFs content nanocomposite is further investigated from 25 to 150℃.With the introduction of small loading BZTNFs,the dielectric permittivity and electric displacement of the nanocomposite are improved at all evaluated temperatures.The 1.0 vol% BZTNFs/PEI possesses a maximal discharged energy density of6.05 J·cm^(-3) with high efficiency of 94.9% at 25℃,then falls to 3.34 J·cm^(-3) with efficiency of 54.6% at 150℃ for the larger remnant displacement.Apparently,the relaxation ferroelectric nanofller of BZTNFs is much effective in increasing the dielectric permittivity of nanocomposite,but its capacity to restrict the migration of the charge carriers at high temperatures is weaker than that of the nanofillers with wider bandgap.The complementation of both kinds of the nanofillers probably provides an approach to available high-temperature dielectric films.