Flexible free-standing graphene-like film electrode for supercapacitors by electrophoretic deposition and electrochemical reduction

Electrophoretic deposition in conjunction with electrochemical reduction was used to make flexible free-standing graphene-like films. Firstly, graphene oxide （GO） film was deposited on graphite substrate by electrophoretic deposition method, and then reduced by subsequent electrochemical reduction of GO to obtain reduced GO （ERGO） film with high electrochemical performance. The morphology, structure and electrochemical performance of the prepared graphene-like film were confirmed by SEM, XRD and FT-IR. These unique materials were found to provide high specific capacitance and good cycling stability. The high specific capacitance of 254 F/g was obtained from cyclic voltammetry measurement at a scan rate of 10 mV/s. When the current density increased to 83.3 A/g, the specific capacitance values still remained 132 F/g. Meanwhile, the high powder density of 39.1 kW/kg was measured at energy density of 11.8 W-h/kg in 1 mol/L H2SO4 solution. Furthermore, at a constant scan rate of 50 mV/s, 97.02% of its capacitance was retained for 1000 cycles. These promising results were attributed to the unique assembly structure of graphene film and low contact resistance, which indicated their potential application to electrochemical capacitors.

Preparation of YBa_2Cu_3O_(7-δ) superconducting thick film on Ni-W tapes via electrophoretic deposition

The preparation of La0.4Sr0.6TiO3 （LSTO） buffer layer and YBa2Cu3O7-δ（YBCO） superconducting thick film by a low cost technology was studied. The crystal orientation of LSTO and YBCO films was detected by X-ray diffraction, the conductivity of LSTO film and superconductivity of YBCO coating were investigated by standard four-probe method. Excellent in-plane alignment, smooth and dense LSTO buffer layer was successfully prepared on textured Ni-W taps by metal organic deposition （MOD）. YBCO thick film was fabricated by electrophoretic deposition （EPD）. The effects of applied voltage and deposition time on the YBCO coatings properties were studied. The results show that the critical current density of the YBCO coating deposited under 138 V for 35 min was about 600 A/cm2 （0 T, 77 K）.

Effect of ball peening of substrate on microstructure, phase evolution and properties of electrophoretically deposited YSZ/(Ni,Al) composite coatings

YSZ/（Ni, Al） composite coatings were deposited on Inconel600 superalloy with ball peening （BP） and without （non BP）treatment using the electrophoretic deposition （EPD） technique, followed by vacuum sintering method. The structures and phaseevolution of the coatings were studied with X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersivespectrometry （EDS）. The relation between microstructures and properties of the BPs-coated samples was discussed. The results showthat the adhesion strength and gain mass of the BPs-coated samples with isothermal oxidation at 1100℃ for 100 h are 3.3 N and0.00817 mg/cm^2, respectively, while those of the non-BPs-coated sample are 2.6 N and 0.00559 mg/cm^2, respectively. The EDSmapping analysis indicates that an obvious outward diffusion of Cr from the substrate to BPs coated samples occurs after isothermaloxidation. The BPs-coated sample shows the superior adhesion and oxidation resistance compared with non-BPs-coated samples.

Study on the Interaction between Strychnine and Bovine Serum Albumin by Capillary Electrophoretic Frontal Analysis

The protein binding constant, binding sites of the Strychnos alkaloid-strychnine and bovine serum albumin （BSA） was determined by capillary electrophoretic frontal analysis （CE-FA） for the first time. The experiment was carried out in a polyacrylamide-coated fused silica capillary （48.4 cm×50 μm i.d., 38.1 cm effective length） with 20 mmol/L citrate/MES buffer （pH 6.0, ionic strength 0.17）. The applied voltage was 12 kV and detection wavelength was set at 257 nm. The plateau height of the peak was employed to determine the unbound concentration of drug in BSA equilibrated sample solution based on the external drug standard in the absence of protein. The present method provides a convenient, accurate technique for the early stage of drug screening.

Capillary Electrophoretic Immunoassay with Laser-induced Fluorescence Detection for Interferon-gamma

Capillary electrophoretic immunoassay with laser-induced fluorescence detection for recombinant human interferon-gamma (IFN-g) was established. The limits of detection for three forms of IFN-g are 6.9 ng/L, 5.7 ng/L and 5.0 ng/L, respectively.

Thermo-Electrochemical Cells Based on Carbon Nanotube Electrodes by Electrophoretic Deposition

Drawbacks of low efficiency and high cost of the electrode materials have restricted the wide applications of the thermo-electrochemical cells(TECs). Due to high specific areas and electrical conductivities, the low cost multi-walled carbon nanotubes(MWNTs) are promising alternative electrode materials. In this work, the MWNT films of up to 16 cm^2 were synthesized on stainless steel substrates by the electrophoretic deposition(EPD) to make the thermo-electrochemical electrodes. MWNT electrodes based on TECs were characterized by cyclic voltammetry and the long-term stability tests with the potassium ferri/ferrocyanide electrolyte. The TECs reached the current density of 45.2 A m^(-2) and the maximum power density of 0.82 W m^(-2). The relative power conversion efficiency of the MWNT electrode is 50 % higher than that for the Pt electrode. Meanwhile, the TECs was operated continuously for 300 h without performance degradation. With the priorities of low cost and simple fabrication, EPD-based MWNT TECs may become commercially viable.

Electrochemical Determination of Cortisol by Capillary Electrophoretic Enzyme Immunoassay

An electrochemical method for detection of cortisol based on capillary electrophoretic enzyme immunoassay has been developed. A limit of detection of 1.7?0-9 mol/L was obtained.

An electrophoretic display driving waveform based on improvement of activation pattern

Electrophoretic display(EPD) technology has become one of the main supporting pillars of the electronic paper display industry.Despite its benefits,the EPD technology suffers from several disadvantages such as non-fixed threshold voltage value for gray scale display.In addition,the display has to repeatedly refresh between white and black states to eliminate ghost image when it needs to update a new image.The traditional driving waveform for the EPD includes four stages: erasing the original image,resetting to black state,clearing to white state,and writing a new image.A flicker can be found when transferring between two adjacent stages.A new driving waveform based on the improvement of activation pattern is proposed to weaken the ghost image and reduce the flicker.Experimental results show that the proposed driving waveform could weaken the ghost image effectively and reduce the number of flickers by 50%.Compared with the traditional driving waveform,the driving waveform of this work has a better performance.

Electrophoretic deposition of hybrid organic-inorganic PTFE/Al/CuO energetic film

Thermite films are typical energetic materials(EMs)and have great value in initiating explosive devices.However,research in thermite film preparation is far behind that of research in thermite powders.Electrophoretic deposition(EPD)is an emerging,rapid coating method for film fabrication,including of energetic composite films.In this work,a polytetrafluoroethylene(PTFE)/Al/CuO organic-inorganic hybrid energetic film was successfully obtained using the above method for the first time.The addition of lithocholic acid as a surfactant into the electroplating suspension enabled PTFE to be charged.The combustion and energy release were analyzed by means of a high-speed camera and differential scanning calorimetery(DSC).It was found that the combustion process and energy release of PTFE/Al/CuO were much better than that of Al/CuO.The main reason for the excellent combustion performance of the hybrid PTFE/Al/CuO system was that the oxidability of PTFE accelerated the redox reaction between Al and CuO.The prepared PTFE/Al/CuO film was also employed as ignition material to fire a B-KNO_3 explosive successfully,indicating considerable potential for use as an ignition material in micro-ignitors.This study sheds light on the preparation of fluoropolymer-containing organic-inorganic hybrid energetic films by one-step electrophoretic deposition.

Effects of Al and Ni doping on oxidation and corrosion resistance of electrophoretic deposited YSZ coatings

Yttria-stablized zirconia(YSZ)/(Ni,Al)coatings were deposited on Inconel600alloy substrate by the electrophoreticdeposition combined with vacuum sintering technique.The effects of isothermal oxidation at1100°C on the composition of thecoatings and the crack healing were investigated,and the corrosion resistance of the coatings in3.5%NaCl(mass fraction)solutionwas also studied.The results showed that the cracks on the coating gradually healed up with the increase of the isothermal oxidationtime.During isothermal oxidation process,the coating composed of Ni3Al was transformed toα-Al2O3particulates.Theα-Al2O3particulates can seal the defects such as pores and cracks,and meanwhile prevent the oxygen diffusion into the coatings.Thepolarization curves and EIS results indicated that the coatings oxidized for40h had a more positive corrosion potential,higherbreakdown potential,higher impedance module at low frequency and much lower corrosion current density compared with YSZcoated and uncoated Inconel600alloys.

Dielectrophoretic force distribution of growing microwires

The Dielectropheretic assembly of electrically functional microwires from nanopartical suspensions is introduced. Meanwhile growth mechanism of the microwires is discussed. The agglomeration is based on the polarization and mobility of particles caused by alternating electric fields, commonly referred to as dielectrophoresis (DEP). The spatial distributions of the electric potential, field and dieletrophoretic force are analytically calculated in terms of AC electrokinetics. The calculated results show that the electrophoretic force, very strong near the apex of the microwire, drops abruptly with increasing distance. The electrophoretic force near the apex of the microwire agrees well with the fact that the nanoparticles are highly concentrated at the end of the tip and subsequently aggregate to extend the wire in the direction of the field gradient.

Electrophoretic Deposition of Titanium Oxide Nanoparticle Films for Dye-Sensitized Solar Cell Applications

Films of titanium oxide nanocrystalline particles (P25) were deposited using an electrophoretic deposition. The film’s characteristics were tuned for applications in dye-sensitized solar cells. Electrophoretic deposition allows control of film characteristics such as porosity and thickness by changing deposition parameters, such as the electric field and deposition time. To increase the efficiency of the dye-sensitized solar cells with films created using electrophoretic deposition, the problem of an electrolyte contamination in the film, which occurred during deposition, was addressed. With the proper chemical post treatment, efficiency of 2.93% with fill factor of 0.55 was obtained when the films were annealed at 450℃. A low annealing temperature of 150℃ resulted in efficiencys of 1.99% with fill factor of 0.68. When the P25 was replaced by hydrothermally fabricated titanium oxide nanocrystalline particles, efficiency of 4.91% with fill factor of 0.55 was obtained.

Electrophoretically deposited binder-free 3-D carbon/sulfur nanocomposite cathode for high-performance Li–S batteries

In the present study,the electrophoretic deposition method was successfully applied as a binder-free and scalable approach to deposit carbonaceous nanomaterials on carbon fiber paper(CFP)for cathode applications in Li-S batteries.The microstructural studies of the EPD-CNT film using scanning electron microscopy(SEM)revealed the formation of a crack-free and porous layer of CNTs being uniformly distributed on the CFP surface.The EPD:CFP/CNT/S cathode delivered a capacity around 2.2 times higher than that obtained in the absence of the EPD-CNT film(CFP/S cell)after 50 cycles and a capacity of935 mAh g^-1 after 100 cycles at 0.1 C.The EPD method was then employed to fabricate layer-by-layer structures where the EPD-CNT film was decorated with carbon black particles.The initial capacity as well as the reversible capacity after 100 cycles was further increased by the EPD:CFP/CNT/KB/S layer-by-layer structure to 1473 and 1033 mAh g^-1,respectively,indicating effective suppression of the shuttle effect.In addition,the rate performance of CFP/S was improved by depositing the EPD-CNT and EPD-CNT/carbon black architectures on CFP surface,and even further enhanced through the co-deposition of CNT and Pt nanoparticles by EPD,delivering a specific capacity of around 730 mAh g^-1 at 1 C.Finally,the cathodes fabricated by EPD were observed to outperform those made by the conventional casting method in terms of cycling performance,internal resistance,and polarization.This difference was ascribed to the non-uniform microstructure of the Cast-CNT film,which resulted in poor interfacial connection between the CNT agglomerates,hindering uniform sulfide/sulfur deposition during cycling.The obtained results suggested that the binder-free C/S nanocomposite cathode made by EPD is key to further enhance the specific capacity and energy density of Li-S batteries.

Micro arc oxidation and electrophoretic deposition effect on damping and sound transmission characteristics of AZ31B magnesium Alloy

Micro arc oxidation(MAO) and electrophoretic deposition(EPD) process are employed to fabricate a dense coating on magnesium alloy to protect it from corrosion in engineering application. The EPD film changes the damping characteristic of magnesium alloy, and both the MAO and EPD process change the bending stiffness of samples being treated. Damping loss factor(DLF) test and sound transmission experiments were carried out for AZ31 B magnesium alloy with coating fabricated by MAO and EPD processes. The results indicate that DLF is improved in frequency range from 0-850 Hz. Bending stiffness of the samples is improved with MAO and EPD treatment. As a result, the sound transmission loss(LST) is improved in the stiffness control stage of the sound transmission verse frequency curve. To the samples by electrophoresis process, the LST is improved in frequency range from 2500-3200 Hz, because the damping loss factor is improved with EPD process. The results are useful for the surface treatment to enhance the damping loss factor, LST and widespread application of magnesium alloy while improving the corrosion resistance.

Optimizing electrophoretic deposition conditions for enhancement in electrical conductivity of carbon fiber/carbon nanotube/epoxy hybrid composites

The effectiveness of optimizing electrical conductivity of carbon fiber/carbon nanotube （CNT）/epoxy hybrid composites via Taguchi method was demonstrated. CNTs were induced on carbon fabric by electrophoretic deposition （EPD） technique. The essential deposition parameters were identified as l） the deposition time, 2） the deposition voltage, 3） the mass fraction of CNTs in suspension, and 4） the distance between the electrodes. An experimental design was then performed to establish the appropriate levels for each factor. An orthogonal array of L9 （34） was designed to conduct the experiments. Electrical conductivity results were collected as the response. The relative influences of design parameters on the response were discussed. Using the model, signal to noise （S/N） ratio and response characteristics for the optimized deposition parameter combination were predicted. The results show clearly that the optimum condition of electrophoretic deposition （EPD） process improves the electrical conductivity of carbon/epoxy hybrid composites.

Electrophoretic Deposition of Hydroxyapatite Coating

Hydroxyapatite (HAP) coatings were deposited onto titanium substrates by electrophoretic deposition (EPD) fromethanol. The results indicated that the addition of very small amount of HCI resulted in a decrease in the aging timeas well as the suspension concentration required to obtain a coating. In addition, the results revealed the existenceof a critical saturated voltage (Vsat), which had significant effect on the quality of deposition. The mean interfacialshear strengths of HAP coatings after sintering were found to be greater than 13 MPa.

Self-assembled Synthesis of Porous TiO_2 Film on the Electrophoretic-deposited Titanate Nanoribbon Film

The porous TiOz film was self-assembled on the surface of electrophoretic-deposited titanate nanoribbon film without the addition of templates by using TiF4 as the precursor. It was found that the hydrolysis of TiF4 was accompanied with the self-assembly processes of TiO2 nanoparticles on the surface of electrophoretic-deposited titanate nanoribbon film, resulting in the formation of porous TiO2 structures. Titanate nanoribbon film was demonstrated to provide the active sites for the effective self-assembly of porous TiO2 nanostructures owing to a large amount of hydroxyl groups. Compared with the nonporous TiO2 film, the prepared porous TiO2 films obviously showed an enhanced photocatalytic activity, which could be attributed to the rapider diffusion and more efficient transport of various reactants and products during photocatalytic reaction in the t^orous structures.

Electrophoretic Coating of Hydroxyapatite on Pyrolytic Carbon Using Glycol as Dispersion Medium

Hydroxyapatite （HA） coatings on pyrolytic carbon were produced via electrophoretic deposition （EPD） using glycol and ethanol as dispersion medium respectively. The effect of the solubility of HA in the dispersion medium on crack occurrence and adherence of the coating was investigated by means of scanning electronic microscope （SEM） and atomic absorption spectrometer （AAS）. The results show that the solubility of HA in glycol is higher than that in ethanol. The usage of glycol as a dispersion medium can reduce the possibility of crack formation and enhance the adhesive strength between the coating and the carbon substrate. The green coatings can be sintered under vacuum at 1 000 ℃ whether the coatings are obtained using ethanol or glycol as dispersion medium. No HA decomposition was observed up to 1 000 ℃ by vacuum sintering by X-ray diffraction （XRD） analysis.

ENZYMO-ROCKET ELECTROPHORETIC ASSAY AND CROSSED AFFINITY ENZYMOIMMUNOELECTROPHORESIS AND ITS APLICATION IN DIAGNOSIS OF PLIMARY LIVER CANCER

A senitive and accurate quantitative method of alphafetoprotein(AFP), enzymo-rocket electrophoretic assay (EREA), was developed by introducing horseradish peroxidase-labeled anti-human AFP antibody into rocket electrophoresis.The lower limit of quantitation ty this method is about 10 ng/ml of AFP.The dose-response curve covers a broader range of concentrations of AFP (10-4000ng/ml)than RIA(0-400 ng/ml) .The accuracy and precision of comparable to that of RIA(r=0.986).Serum AFP measured in 100 patients with primary liver cancer by this method,88% had levels over 25ng/ml.The crossed affinity enzymoimmunoelectrphoresis is a combination of lentil lectin(LCA)affinity electrophoresis and enzymo-rocket electrophoresis,it has been possible to separate the AFP into two variants,LCA-reactive(LCA-R)and LCA-nonreactive (LCA-N)fractions.The advantages of this method are high sensitivity,rapid(6-7h),and can be effectively used to differentiate the primary liver cancer and benign liver disease.