Effects of Surface Pretreatment of Titanium Substrates on Properties of Electrophoretically Deposited Biopolymer Chitosan/Eudragit E 100 Coatings

The preparation of the metal surface before coating application is fundamental in determining the properties of the coatings, particularly the roughness, adhesion, and corrosion resistance. In this work, chitosan/Eudragit E 100 (chit/EE100) were fabricated by electrophoretic deposition (EPD) and both their microstructure and properties were investigated. The present research is aimed at characterizing the effects of the surface pretreatment of titanium substrate, applied deposition voltage, and time on physical, mechanical, and electrochemical properties of coatings. The coating’s microstructure, topography, thickness, wettability, adhesion, and corrosion behavior were examined. The applied process parameters influenced the morphology of the coatings, which affected their properties. Coatings with the best properties, i.e., uniformity, proper thickness and roughness, hydrophilicity, highest adhesion to the substrate, and corrosion resistance, were obtained after deposition of chit/EE100 coating on nanotubular oxide layers produced by previous electrochemical oxidation.

Preparation and analysis of electrochromic properties of poly(3,4 ethylene dioxythiophene)

The film of PEDOT was prepared in this study via electrochemical polymerization using EDOT as monomer in LiClO4/PC solution. The effects on the properties of the film were surveyed including the deposition voltage and deposition time. The morphology of the film was observed by scanning electron microscopy. The electrochromic kinetics was analyzed by combination of electrochemical workstation and UV-Visible spectrophotometer such as the transmittance, transmittance contrast, coloring efficiency and the response time. The results indicated the film presents a coral shape despites of the deposition voltage and the deposition time. In case of the application as electrochromic film, the optimal process condition is 1.3 V and 24 s. The corresponding transmittance is 82.77% in fade state. The transmittance contrast is 17.87%, and the coloring efficiency is about 117.92 cm2/C, the response time is 0.52 s.

Effect of Deposition Voltage on Layer Thickness, Microstructure, Cu/Ni Sheet Resistivity of Deposition Results by Magnetic Field Electroplating Assisted Technique

The purpose of this research is to make the Cu/Ni thin layer as an alternative to basic RTD materials through electroplating methods assisted by magnetic fields. Electroplating was carried out with variation in deposition voltage ranging from 1 to 5 V. The results of this study indicate that the deposition voltage applied to the coating affects the thickness, sheet resistivity, and microstructure of the coating. Thickness increases with increasing deposition voltage. The diffraction intensity and crystal size tend to increase with increasing deposition voltage. The distance between Bragg planes after the coating is almost equal for all samples. The highest sheet resistivity was obtained in the coating sample with a 4-volt deposition voltage.

Fabrication and Characterization of Ag-Sr Doped Hydroxyapatite/chitosan Coatings Deposited on 316L SS via Electrophoretic Deposition

In this study, silver-strontium doped hydroxyapatite (AgSr-HA)/chitosan composite coatings were deposited on stainless steel (SS) substrate via electrophoretic deposition (EPD) technique. The EPD parameters such as the concentration of Ag Sr-HA particles in the suspension, applied voltage and deposition time were optimized on by the Taguchi Design of Experiment (DoE) approach. DOE approach elucidated that the “best” coating was obtained at; the deposition voltage of 20V, deposition time of 7 minutes, and at 5 g/L of Ag Sr-HA particles in the suspension. The optimum coatings were characterized by using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. SEM images confirmed the deposition of chitosan/Ag Sr-HA on the SS substrate. The wettability studies indicated the hydrophilic nature of the chitosan/Ag Sr-HA coatings, which confirmed the suitability of the developed coatings for orthopedic applications. The average surface roughness of the chitosan/Ag Sr-HA coatings was in a suitable range for the attachment of bone marrow stromal cells. Chitosan/Ag Sr-HA coatings showed a potent antibacterial effect against the Gram-Positive and Gram-negative bacteria.

Biomineralization of 2304 duplex stainless steel with surface modification by electrophoretic deposition

A hydroxyapatite (HAp) coating on 2304 duplex stainless steel (DSS) through an electrophoretic deposition process has been investigated in this work. The deposition voltage was 30 V with a time of 2 min. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy analyses were used for the microstructural and chemical examination of coatings, respectively. The Ca to P ratio for the nano HAp coating on 2304 DSS has been determined as equal to 1.642. It was observed from X-ray diffraction patterns that HAp nanoparticles were successfully combined into the substrate. The corrosion behavior of all samples was tested in simulated body fluid using a potentiodynamic polarization study. A homogeneous structure with a thin crack-free layer was obtained. Moreover, the porosity of this coating was very low leading to a high corrosion resistance, thus promoting good biocompatibility.

Diamond-like carbon as gate dielectric for metal–insulator–semiconductor applications

Diamond-like carbon (DLC) has been studied as a dielectric material for future metal–insulator–semiconductor (MIS) technology. In this paper, ultrathin DLC films were deposited on silicon substrates by using the dc magnetron sputtering technique at various deposition voltages. The current–voltage characteristics indicated that the leakage currents of the MIS devices decreased with an increase in deposition voltages, and that a low leakage current ([Formula: see text] A/cm2) was achieved at −2 V bias voltage. The deposition voltage effects on the structures of films were investigated through Raman spectroscopy, which indicated that the sp3 bonding fraction decreased with an increase in the deposition voltage. The ramp-voltage breakdown test revealed high effective breakdown electric field ([Formula: see text]85 MV/cm) for the MIS device with the DLC film deposited at 1100-V deposition. Stress-induced leakage current measurement indicated that the DLC film exhibited excellent reliability.

Effect of Cu2O Content in Electrodeposited CuOx Film on Perovskite Solar Cells

It is well known that the different proportions of CuO and Cu2O in CuOx hole transfer materials have a great influence on the hole transport property as well as the device performances of perovskite solar cells (PSCs). In this paper, we changed the content of Cu2O in the film by controlling the deposition voltage during electrodeposition, and the effects of different contents of Cu2O in the films on the device were investigated for the first time. It was found that the content of Cu2O in the film reached the highest point with the deposition voltage 0.5[Formula: see text]V, such films have the highest transmittance and carrier mobility. After assembling the device, the power conversion efficiency (PCE) of the champion device reached 13.48% under a one-sun AM 1.5[Formula: see text]G (100[Formula: see text]mW/cm[Formula: see text] illumination. Furthermore, the unpackaged device based on CuOx still retained over 75% PCE after being placed in the ambient condition (30–40% humidity, 20–30[Formula: see text] for 500[Formula: see text]h.

The effects of deposition potential on the optical, morphological and mechanical properties of DLC films produced by electrochemical deposition technique at low voltages

Diamond-like carbon (DLC) films were electrochemically deposited onto indium tin oxide (ITO) substrates using acetic acid and deionized water as electrolyte at low deposition voltages (2.4 V and 60 V). The transmittance of the films was investigated by UV spectrometry. Transmittance measurements versus wavelength revealed that the films transmit 86 % to 89 % light in visible region and band gap of the films varies between 3.87 eV and 3.89 eV. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used for structural characterization to evaluate surface morphology of the DLC films. The grain size and the surface roughness increased for the films prepared at higher deposition potential, while their measured average height decreased. The mechanical properties (hardness H and elastic modulus Er) were determined from load-displacement curves which were obtained by using nanoindentation method. Hardness and elastic modulus of the films increased as the deposition voltage of the films increased from 2.4 V to 60 V.