Cathodic Pulse Research Articles

Simultaneous detection of indole and 3‐methylindole using boron‐doped diamond electrodes

The simultaneous electrodetection of indole and 3‐methylindole was investigated in this paper. The detection was performed using a boron‐doped diamond (BDD) electrode to take advantage of its remarkable electrochemical properties (Fujishima et al., Diamond Electrochemistry (Elsevier, 2005) . In order to improve the selectivity between indole and 3‐methylindole, square‐wave voltammetry (SWV) was used. We showed that BDD electrodes fouled either from oxidation of indole or 3‐methylindole could be efficiently reactivated in LiClO4 aqueous solutions using trains of short anodic and cathodic pulses applied to the working electrode. We were able with this approach to measure simultaneously both indole and 3‐methylindole in aqueous solutions in the range of 10–500 μM with the limits of detection (LOD) found to be 3 × 10−2 μM for indole and 5 × 10−2 μM for 3‐methylindole. Both indoles were also detected successfully following extraction from pork fat. This work opens up the way toward systematic detection of indole and 3‐methylindole in processed foodstuffs, with a strong industrial interest for the detection of boar taint in pork meat.

Analysis of Pulse-Reverse Nb Electropolishing with H2so­­ 4 for Srf Cavities

The performance of superconducting radiofrequency (SRF) cavities is greatly affected by the topography of the interior surface, so it is imperative that the surface be clean metal as smooth as possible. Currently, the 1:10 volume ratio HF (49%) and H2SO4 (96%) electrolyte was widely used for high field SRF cavity production, the problem with using HF is that it is dangerous both to people and to the environment. A new method that has been developed to smooth the surface is pulse reverse electropolishing (EP). This method uses aqueous H2SO­­ 4 as the electrolyte and alternating anodic and cathodic pulses to oxidize the niobium (Nb) and then remove the oxide from the surface [1]. Previous studies have shown that pulse reverse EP effectively polishes the surface of Nb SRF cavities [1,2].. In order to better understand polishing mechanism and optimize the operating parameter for cavity production, systematic electrochemical experiments have been carried out to further explore the oxide removal process, the effect of positive and negative pulse duration, pulse structure, off time between positive and negative pulses, concentration of H2SO­­ 4, and determine optimum polishing parameters for reliable Nb SRF cavity production process, the results will be reported.

Electrochemical Dispersion Method for TiO<sub>2</sub> Nanoparticles Preparation

Electrochemical dispersion method for producing of TiO2 nanoparticles in anatase form has been proposed. It was found that the ratio between the current density of the anodic and cathodic pulses has an impact on the specific surface area (90–155 m2 g-1) and particles size (≈10-14 nm) of prepared TiO2 powders was but doesn’t impact on the products composition. The electrolyte concentration doesn’t impact on the rate of Ti electrode dispersion as well as TiO2 powders morphology.

Electrogenerated chemiluminescence induced by sequential hot electron and hole injection into aqueous electrolyte solution

Hole injection into aqueous electrolyte solution is proposed to occur when oxide-coated aluminum electrode is anodically pulse-polarized by a voltage pulse train containing sufficiently high-voltage anodic pulses. The effects of anodic pulses are studied by using an aromatic Tb(III) chelate as a probe known to produce intensive hot electron-induced electrochemiluminescence (HECL) with plain cathodic pulses and preoxidized electrodes. The presently studied system allows injection of hot electrons and holes successively into aqueous electrolyte solutions and can be utilized in detecting electrochemiluminescent labels in fully aqueous solutions, and actually, the system is suggested to be quite close to a pulse radiolysis system providing hydrated electrons and hydroxyl radicals as the primary radicals in aqueous solution without the problems and hazards of ionizing radiation. The analytical power of the present excitation waveforms are that they allow detection of electrochemiluminescent labels at very low detection limits in bioaffinity assays such as in immunoassays or DNA probe assays. The two important properties of the present waveforms are: (i) they provide in situ oxidation of the electrode surface resulting in the desired oxide film thickness and (ii) they can provide one-electron oxidants for the system by hole injection either via F- and F+-center band of the oxide or by direct hole injection to valence band of water at highly anodic pulse amplitudes.

Pulse potential electrodeposition of (112)-textured chalcopyrite CuInSe2 films from acidic aqueous solutions

A pulsed potential method was used to synthesize chalcopyrite CuInSe2 films by a single step electrodeposition process from acidic aqueous solutions of Cu(II) and In(III) nitrates, selenium oxide (SeO2) and citrate (C6H5Na3O7) additive. The effect of deposition parameters, such as bath composition, pulsed potential profile, electrolysis charge, and bath temperature, on the structure, composition and morphology of the obtained films was investigated. Conditions for producing coherently uniform deposits with near stoichiometric compositions were specified. Pulse plating at room temperature from pH 1.6–1.8 baths with millimolar concentrations of precursors, and a five to ten-fold excess of In(III) over Cu(II), employing the moderately high frequency of 1Hz and short cathodic pulses, was found leading to direct formation of CuInSe2 crystallites in strongly (112)tetr-textured films, free from bulk secondary phases.

EQCM study of oxygen cathodes in DMSO LiPF6 electrolyte

The oxygen reduction reaction (ORR) in DMSO containing LiPF6 has been studied with the electrochemical quartz crystal microbalance (EQCM) during galvanostatic cathodic and anodic pulses, chronoamperometry and cyclic voltammetry experiments. We disclose here for the first time gravimetric evidence with the EQCM of the different mechanistic models that apply to the ORR in LiPF6/DMSO electrolyte: (i) Surface electrochemical/chemical deposition of Li2O2(s) and (ii) solution phase disproportion of LiO2(soln) yields large Li2O2 particles. The mass per electron detected with the EQCM depends on the respective current rates and thus on the mechanisms, i.e. 23g/F for the formation of Li2O2 thin film at high current density and much larger values for low current density due to solvent co-deposition and further degradation.

Ionic current rectification in organic solutions with quartz nanopipettes.

The study of behaviors of ionic current rectification (ICR) in organic solutions with quartz nanopipettes is reported. ICR can be observed even in organic solutions using quartz pipettes with diameters varied from several to dozens of nanometers, and the direction of ICR is quite different from the ICR observed in aqueous phase. The influences of pore size, electrolyte concentration, and surface charge on the ICR have been investigated carefully. Water in organic solutions affects the direction and extent of ICR significantly. Mechanisms about the formation of an electrical double layer (EDL) on silica in organic solutions with different amount of water have been proposed. An improved method, which can be employed to detect trace water in organic solutions, has been implemented based on Au ultramicroelectrodes with cathodic differential pulse stripping voltammetry.

Coelectrodeposition of Ternary Mn-Oxide/Polypyrrole Composites for ORR Electrocatalysts: A Study Based on Micro-X-ray Absorption Spectroscopy and X-ray Fluorescence Mapping

Low energy X-ray fluorescence (XRF) and soft X-ray absorption (XAS) microspectroscopies at high space-resolution are employed for the investigation of the coelectrodeposition of composites consisting of a polypyrrole(PPy)-matrix and Mn-based ternary dispersoids, that have been proposed as promising electrocatalysts for oxygen-reduction electrodes. Specifically, we studied Mn–Co–Cu/PP, Mn–Co–Mg/PPy and Mn–Ni–Mg/PPy co-electrodeposits. The Mn–Co–Cu system features the best ORR electrocatalytic activity in terms of electron transfer number, onset potential, half-wave potential and current density. XRF maps and micro-XAS spectra yield compositional and chemical state distributions, contributing unique molecular-level information on the pulse-plating processes. Mn, Ni, Co and Mg exhibit a bimodal distribution consisting of mesoscopic aggregates of micrometric globuli, separated by polymer-rich ridges. Within this common qualitative scenario, the individual systems exhibit quantitatively different chemical distribution patterns, resulting from specific electrokinetic and electrosorption properties of the single components. The electrodeposits consist of Mn3+,4+-oxide particles, accompanied by combinations of Co0/Co2+, Ni0/Ni2+ and Cu0,+/Cu2+ resulting from the alternance of cathodic and anodic pulses. The formation of highly electroactive Mn3+,4+ in the as-fabricated material is a specific feature of the ternary systems, deriving from synergistic stabilisation brought about by two types of bivalent dopants as well as by galvanic contact to elemental metal; this result represents a considerable improvement in material quality with respect to previously studied Mn/PPy and Mn-based/PPy binaries.

Characterisation of Oxide Coatings Produced on Aluminium by PEO at Different Frequencies of Pulsed Current

The Plasma Electrolytic Oxidation (PEO) is a surface modification process that allows producing protective oxide coatings on light metal alloys. These coatings are characterized by high microhardness and wear resistance. Changes of electrical conditions of alternate current during process, such as duration and frequency of anodic and cathodic pulses, influence on layer growth rate, its microstructure and final properties. In this study aluminium samples were oxidized at different electrical parameters in sodium silicate electrolyte. The growth rates of oxide layers were determined by mass change and thickness measurements. The microstructure of the obtained coatings was investigated by using scanning electron microscope. Additionally, phase compositions of coatings was determined by X-ray diffraction on top surfaces of layers. Generally, shorter duration and higher frequency of anodic pulses provides more uniform structure at lower growth rate. Nevertheless, there are certain ranges of electrical parameters that provide decent uniformity of oxide coatings.

Iterative electrodes increase neural recruitment for deep brain stimulation.

Deep brain stimulators require surgical replacement when primary cell batteries are depleted. We designed novel electrode contact geometries based on the principle of iterative element addition as a method of increasing perimeter. Our hypothesis was that these novel, high-perimeter designs would increase surface current density variation and neuronal activation, thus improving stimulation efficiency by decreasing power requirement. Finite element models of iterative electrodes displayed greater surface current density variations on the electrode surface. Subsequent analysis of their activation efficiency when 100 neurons were randomly positioned either parallel or perpendicular to the electrode yielded higher stimulation efficiencies in response to a monophasic cathodic voltage pulse with a pulse width of 100 μs. Recruitment curves showing the percentage of activated axons as a function of stimulation intensity yielded a ~8% and ~24% reduction in threshold voltage and a ~2% and ~28% reduction in power consumption when nerve fibers were oriented parallel and perpendicular to the electrode, respectively. This heightened efficiency would reduce the frequency of surgical replacements of depleted stimulators, as well as induce fewer side effects associate with high voltage requirement for therapeutic stimulation.

Voltammetric Determination of Neonicotinoid Pesticides at Disposable Screen‐Printed Sensors Featuring a Sputtered Bismuth Electrode

AbstractThis work reports the determination of 5 neonicotinoid pesticides (Clothianidin, Imidacloprid, Thiamethoxam, Nitenpyram and Dinotefuran) in water samples by cathodic differential pulse (DP) voltammetry at screen‐printed disposable sensors featuring a sputtered bismuth thick‐film working electrode, a Ag reference electrode and a carbon counter electrode. The performance of the bismuth thick‐film electrodes was compared to that of a home‐made bismuth thin‐film electrode and a bismuth‐bulk electrode. The electrodes were further characterized by electrochemical and optical techniques. The effect of the pH of the supporting electrolyte on the DP reduction currents of the 5 pesticides was studied. The limits of quantification (LOQs) in 4 water matrices (distilled water, tap water, mineral water and surface water) were in the range 0.76 to 2.10 mg L−1 but severe matrix effects were observed in the analysis of mineral and, especially, surface water samples. Using a solid‐phase extraction (SPE) procedure using Lichrolut EN cartridges and elution with methanol, the matrix effects were substantially reduced and the LOQs were in the range 9 to 17 µg L−1. The recoveries of surface water samples spiked with the 5 target neonicotinoids at two concentration levels (20 and 50 µg L−1) were in the range 89 to 109 % and the % relative standard deviations ranged from 4.3 to 7.2 %.

Electrochemically Deposited Sb and In Doped Tin Sulfide (SnS) Photoelectrodes

Semiconducting tin sulfide (SnS) was deposited electrochemically from electrolytes containing Sn and S precursors and conditions optimized to maximize its performance as a photoelectrode. Films composed of primarily orthorhombic SnS were electrodeposited on titanium substrates from electrolyte containing 20 mM SnSO4 and 100 mM Na2S2O3 at pH 2.5. For deposition a cathodic pulse of −1.25 V vs Ag/AgCl was applied for 2.75 s followed by a 0.25 s pulse of +0.25 V vs Ag/AgCl repeated for 30–45 min. The films were annealed in argon at 300 °C for 3 h. The addition of SbCl3 (<5%) to the electrolyte gave rise to doping of the SnS film with Sb which resulted in an increase in the photocurrent as well as a switch from p- to n-type semiconducting behavior in an acidified Na2S2O3 electrolyte. Incorporation of p-type In into the films from addition of In(NO3)3 had a smaller effect on the measured photocurrent, and at higher precursor concentration (>5%) the dopants resulted in the formation of secondary phases of Sb and In oxides with reduction in the measured photocurrent. This doped SnS material could potentially be used in systems for the photoelectrochemical production of hydrogen and oxidation of organic wastewater. Density functional theory calculations supported the experimentally observed conductivity increase for photoelectrons as an Sb dopant induced curvature of the valence band. These calculations also provided an explanation to the previous experimental work where Sb doping was used to decrease the resistivity of SnS films. The combination of an automated electrodeposition of an earth abundant metal sulfide with the theoretical calculations to guide the synthesis is an exemplar of how to improve the efficiency of SnS-based solar energy conversion materials.

Experimental design for optimizing the corrosion resistance of pulse reverse electrodeposited graphene oxide thin film

In this study, linear polarization resistance (LPR) of pulse reverse electrodeposited graphene oxide (PREGO) coating is optimized by design of experiments approach (central composite design). Pulse current density (i), cathodic (Tc) and anodic (Ta) pulse durations, and total electrodeposition time (Tt) are selected as the substantial factors. The best prediction model proposes a definitive linear relation without any significant interaction of the LPR by analysis of variance. The desirable value of LPR was predicted equal to 5358 Ω cm2, obtaining at the pulse current density of 235.62 mA cm−2, Ta of 7.75 ms, Tc equal to 3.25 ms (f = 100 Hz), and Tt of approximately 225 s. Appearance of the XRD peaks at 25.11° and 27.18° and declining coating impedance up to 21 Ω cm2, as well as the elimination of functional groups at FT-IR spectra, are vividly promised the formation of sp2 domains in the PREGO coating.

Effect of Stimulus Waveform of Biphasic Current Pulse on Retinal Ganglion Cell Responses in Retinal Degeneration (rd1) mice.

A retinal prosthesis is being developed for the restoration of vision in patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Determining optimal electrical stimulation parameters for the prosthesis is one of the most important elements for the development of a viable retinal prosthesis. Here, we investigated the effects of different charge-balanced biphasic pulses with regard to their effectiveness in evoking retinal ganglion cell (RGC) responses. Retinal degeneration (rd1) mice were used (n=17). From the ex-vivo retinal preparation, retinal patches were placed ganglion cell layer down onto an 8×8 multielectrode array (MEA) and RGC responses were recorded while applying electrical stimuli. For asymmetric pulses, 1st phase of the pulse is the same with symmetric pulse but the amplitude of 2nd phase of the pulse is less than 10 µA and charge balanced condition is satisfied by lengthening the duration of the pulse. For intensities (or duration) modulation, duration (or amplitude) of the pulse was fixed to 500 µs (30 µA), changing the intensities (or duration) from 2 to 60 µA (60 to 1000 µs). RGCs were classified as response-positive when PSTH showed multiple (3~4) peaks within 400 ms post stimulus and the number of spikes was at least 30% more than that for the immediate pre-stimulus 400 ms period. RGC responses were well modulated both with anodic and cathodic phase-1st biphasic pulses. Cathodic phase-1st pulses produced significantly better modulation of RGC activity than anodic phase-1st pulses regardless of symmetry of the pulse.

Design of Experiments for Pulse Reverse Electrodeposition of Graphene Oxide toward Hydrogen Evolution Reaction

Surface active sites of pulse reverse electrodeposited graphene oxide (PREGO) coating is optimized by design of experiments approach (central composite design). Applied current density (i), cathodic (Tc) and anodic (Ta) pulse durations, and total electrodeposition time (Tt) are selected to interpret the hydrogen evolution reaction (HER). The analyses of variance (ANOVA) are carried out on the outcomes of the designed experiments. A definitive linear relationship without any significant interaction was introduced as the best prediction model. Moreover, the results indicating the Ta and Tc are the most significant model terms. The best desirable value of the exchange charge on the cyclic voltammetry (CV) was obtained equal to 36785.43 μC which collected on the i, Tc, Ta and Tt of 235.62 mA cm−2, 7.75 ms, 3.25 ms (f = 100 Hz) and 225 s respectively. Various experiments such as X-ray diffraction, Fourier transform infrared, Raman, and electrochemical impedance spectroscopies as well as the field emission scanning electron microscopy and dynamic polarization test were carried out to characterize the optimized thin film. The corrosion resistance enhanced approximately 6.9 times accompanied by an inhabitation efficiency of 85.53%. Besides, the Rf value equal to 116.36 illustrates 3D graphene has a high potential in the HER field.

Co100−xFex magnetic thick films prepared by electrodeposition

Co–Fe films are grown onto plane pre-treated Cu foils; the effects of the alloy composition on the morphology and the crystal texture of the electrodeposited films and their anisotropic magnetic hysteresis properties are explored. Nucleation and crystallization mechanisms in these Co-rich layers are also investigated with pulse-reverse plating techniques, using the first cathodic pulse current–time transients. In the diffusion controlled regime the deposition mechanism is found to involve progressive nucleation with three-dimensional (3D) growth, except for the equiatomic Fe50Co50 solution where nucleation tends to become instantaneous. The different morphologies and size scales observed are described and correlated with coercivity. The films are electrodeposited onto electrochemically pre-treated Cu substrates from feeds of nominal Fe/Co mol ratios between 0/100 and 50/50. The composition of the deposited layers, as determined by energy dispersive X-ray spectroscopy, are quite close to the nominal values. Cyclic voltammetry determinations exhibit only a single reduction process on the cathode, indicating that a unique (Co100−xFex) phase grows. Depending on composition and on the substrate pre-treatment, these layers exhibit textures with features of different sizes. X ray diffraction patterns indicate that the nanostructures with Fe contents above 20at.% crystallize in a body-centered cubic cell, while samples with Fe contents below this value are fcc. Regarding the effect of composition on the morphology, Co and Co-rich layers are compact, with large (100–300nm) agglomerates of quite equiaxed, densely packed particles (average 50nm); as the iron content increases above 15at.%, faceted particles 100nm in size are observed. All the electrodeposited layers are soft ferromagnetic at room temperature, with an in plane easy axis; coercive fields/forces between 10mT and 71mT are measured at 300K.

Activation and inhibition of retinal ganglion cells in response to epiretinal electrical stimulation: a computational modelling study

Objective. Retinal prosthetic devices aim to restore sight in visually impaired people by means of electrical stimulation of surviving retinal ganglion cells (RGCs). This modelling study aims to demonstrate that RGC inhibition caused by high-intensity cathodic pulses greatly influences their responses to epiretinal electrical stimulation and to investigate the impact of this inhibition on spatial activation profiles as well as their implications for retinal prosthetic device design. Another aim is to take advantage of this inhibition to reduce axonal activation in the nerve fibre layer. Approach. A three-dimensional finite-element model of epiretinal electrical stimulation was utilized to obtain RGC activation and inhibition threshold profiles for a range of parameters. Main results. RGC activation and inhibition thresholds were highly dependent on cell and stimulus parameters. Activation thresholds were 1.5, 3.4 and 11.3 μA for monopolar electrodes with 5, 20 and 50 μm radii, respectively. Inhibition to activation threshold ratios were mostly within the range 2–10. Inhibition significantly altered spatial patterns of RGC activation. With concentric electrodes and appropriately high levels of stimulus amplitudes, activation of passing axons was greatly reduced. Significance. RGC inhibition significantly impacts their spatial activation profiles, and therefore it most likely influences patterns of perceived phosphenes induced by retinal prosthetic devices. Thus this inhibition should be taken into account in future studies concerning retinal prosthesis development. It might be possible to utilize this inhibitory effect to bypass activation of passing axons and selectively stimulate RGCs near their somas and dendrites to achieve more localized phosphenes.

Corrosion mechanisms of Zn(Mg,Al) coated steel: The effect of HCO3− and NH4+ ions on the intrinsic reactivity of the coating

The effect of NH4+ and/or HCO3− ions on the reactivity of hot dip galvanized steel and Zn - 3.7wt. % Mg–3wt. % Al coated steel in aqueous solutions containing Cl− was studied by direct measurement of the elemental dissolution rates of Zn, Mg and Al by atomic emission spectroelectrochemistry at open circuit potential and under alternating anodic (0.95V vs SCE) and cathodic (-1.15V vs SCE) potentiostatic pulses. The anodic reactivity of ZnMgAl coating was higher compared to a standard hot dip galvanized coating in all electrolytes. Mg rich phases were selectively dissolved. NH4+ increased the anodic reactivity of Zn in both coatings, suppressed the accumulation of zinc corrosion products, and inhibited Al dissolution at open circuit. HCO3− increased the accumulation of insoluble zinc corrosion products as well as the anodic reactivity. The cathodic current on the fresh surface of ZnMgAl in 0.1M NaCl and in the mixture of 0.1M NH4Cl and 0.1M NaHCO3 was the same but cathodic dissolution of Al was higher in the mixed electrolyte. A series of alternating anodic and cathodic potentiostatic pulses demonstrated that the preliminary anodic polarization modified the following response of ZnMgAl on the cathodic pulse: the cathodic Al dissolution was significantly delayed and the cathodic current increased in mixed electrolyte. The cathodic current in NaCl was not affected by the preliminary anodic polarization. The effect was interpreted using a hypothesis of the formation of low soluble Mg carbonates during anodic polarization. Layered double hydroxides were not detected on ZnMgAl coatings after short experiments in mixed electrolyte. In contrast, Mg(OH)2, which is thermodynamically less stable at slightly alkaline pH, was detected. This indicates the importance of kinetic factors for the formation of corrosion products during the first stages of corrosion.

Surface Finishing of Strongly Passive Biomedical Materials, such as Nitinol, in Low- and Non-Acid Electrolytes

A process for surface finishing of biomedical alloys is described. For strongly passivating metals, electropolishing under direct current (DC) electric fields in a simple electrolyte can lead to a roughened surface. To remove the passive film, aggressive chemicals are added to the electrolyte, for example, hydrofluoric acid may be used to depassivate the surface.[1]A pulse/pulse reverse waveform can be used to electropolish passive materials, by tuning anodic pulses to control mass transport and current distribution, interspersed with cathodic pulses to depassivate the surface.[2]-,[3],[4],[5]Off-times inserted between the anodic and cathodic pulses facilitate replenishment of reacting species and removal of by-products and heat. The cathodic pulse eliminates the need for HF or other chemicals to remove the surface oxide. While the exact mechanism of depassivation is unknown at this stage, we speculate that the cathodic pulses remove the oxide either by direct electrochemical reduction or indirect chemical reduction, and restore the virgin metal surface prior to the next anodic pulse. The amplitude of the cathodic pulses required for depassivation is material specific, and appears to be based on the strength of the passive film.The inclusion of cathodic pulses and off-times suggests that the overall process would be slower than a conventional DC process, which is undesirable for industrial implementation. However, the maximum current density during the anodic pulse is higher than the DC limiting current density. Therefore, the overall removal rate of a pulsed process can rival or exceed that of a DC process despite a duty cycle that is less than 100%, while enjoying enhanced process performance.Studies in near-neutral aqueous solutions have demonstrated the feasibility of eliminating toxic solutions from manufacturing of biomedical devices. The best processing conditions to date for Nitinol in 17 w/w% H2SO4 has resulted in a final surface Ra of 0.19 µm. We have electropolished Ti-15Mo and Ti-Al-Nb alloys in 10 w/w% H2SO4 or 150 g/L Na2SO4to an Ra of 0.12 µm and 0.23 µm, respectively. We have done preliminary work on Ti-6Al-4V, achieving a near-mirror like surface finish.For electropolishing of stainless steels in an aqueous NaCl-NaNO3 electrolyte, a waveform sequence of short anodic pulses with interspersed cathodic pulses for 30 s followed by a waveform with long anodic pulses and interspersed cathodic pulses for 15 s has achieved a final Raof 0.026 µm (Figure 1: SS316 surface before and after FARADAYIC® Electropolishing). Finally, we have electropolished molybdenum to a mirror-like surface finish, and investigated on cobalt-chrome alloys and rhenium alloys.In summary, we have described a pulse reverse electropolishing process that may be applied to biomedical alloys using low viscosity aqueous electrolytes, devoid of aggressive chemicals for depassivating the surface. Consequently, the safety and chemical handling and disposal issues associated with pulse reverse electropolishing are minimized. In addition, the need for active chilling is minimized by the appropriate use of off-times and we anticipate that the process reproducibility and robustness are greatly enhanced. Acknowledgements: The authors acknowledge the financial support of Faraday corporate, NIH Grant No.1 R43 HL095216-01A1, DOE P.O. No. 594128 and DOE Contract No. DE-SC0004588.

Ultrasound-Pulse Electrodeposition Preparation of Fe-Nano ZrO&lt;sub&gt;2&lt;/sub&gt; Functional Gradient Coating

Objective On the basis of the experimental investigation of Fe-ZrO2nanocomposite coating, nanoZrO2particles were added to the bath to prepare the nanocomposite coating of Fe-ZrO2with electroplating methods and laser cladding. Methods Study the effects of nanocontent, cathodic pulse current density, duty cycle, the ultrasonic frequency content of the coating surface Nano, orthogonal optimization of process parameters. Results The results show that nanoparticles concentration 10 g/l, the cathode current density pulse 4A/dm2, the duty cycle 20%, ultrasonic frequency 180W, nanocomposite coating capacity of up to 5.5wt%. Conclusion Fe-ZrO2nanocomposite coating improved abrasion and Corrosion of the binary composite coating.