Leveling power of sulfate electrolytes with organic additives in electrodeposition of tin-indium alloy

Optimal organic additives providing surface microprofile leveling were found in a study of the electrodeposition of a tin-indium alloy from sulfate electrolytes.     

Electrodeposition of tin-indium alloy from a sulfate electrolyte in the presence of organic substances

Electrodeposition of the Sn-In alloy from a sulfate electrolyte in the presence of synthanol, formalin, and butynediol-1,4 was studied. An electrolyte composition and conditions for obtaining an alloy of prescribed composition are suggested.     

Electrodeposition of tin-cobalt alloy from a sulfate electrolyte with organic additives

Electrodeposition of a tin-cobalt alloy from a sulfate electrolyte with organic additives was studied.     

Effect of sulfamate-citrate electrolyte pH on the Ni-W alloy electrodeposition

Effects of sulfamate-citrate electrolyte pH on the cathodic polarization, content of W in Ni-W alloys, and crystallite grain size are studied by cyclic voltammetry, scanning electron microscopy, and energy dispersion spectroscopy. It is shown that a medium pH has the determining effect on the electrolyte and deposit properties; in a neutral medium, properties of deposits are optimal. A unique dependence of the microhardness on the alloy’s composition is found.     

Electrodeposition of lustrous nickel coatings from a sulfate electrolyte in the presence of organic substances

Electrodeposition of nickel from a sulfate electrolyte containing 2,5-dimethyl-3-hexine-2,5-diol, formaldehyde, and benzaldehyde was studied.     

Effect of the composition of pyrophosphate electrolyte on the kinetics of cobalt electrodeposition

Potentiometric titration was used to study the equilibrium in a solution of the pyrophosphate cobalt complex in a wide range of pH values. The effect of the solution pH and the concentrations of the cobalt complex and the free ligand on the kinetics of cobalt electrodeposition was examined.     

Electrodeposition of chromium-molybdenum alloy from electrolyte based on chromium(III) sulfate

The conditions of chromium-molybdenum plating from the electrolytes based on chromium(III) compounds are studied. It is shown that the deposits containing to 2 wt % molybdenum can be obtained by introducing sodium molybdate into the composition of electrolytes based on chromium(III) compounds. The introduction of molybdenum into the composition of chromium electrodeposits enhances their corrosion resistance in the media containing chloride ions.     

Ni-W alloy coatings deposited from a citrate electrolyte

Ni-W alloy coatings were deposited by applying current pulses with different pulse parameters at 60°C onto mild steel substrates from aqueous electrolytes with different tungstate concentration. Morphology and composition of the alloys were analyzed by SEM and EDX, respectively. XRD was used to determine metallic phases. Scanning electron micrographs revealed that deposition parameters had a strong effect on the morphology of the coatings. Increasing the duty cycle or decreasing the off time led to a compact morphology. Corrosion properties of the coatings were investigated by potentiodynamic polarization in a chloride medium. It was found that compact morphology of the deposits and high content of tungsten in the coating contribute to satisfactory corrosion results of Ni-W alloy coatings under the conditions studied.     

Electrodeposition of cadmium from a sulfate electrolyte in the presence of a fixative

Electrodeposition of cadmium from a sulfate electrolyte containing CdSO₄ · 8/3H2O, H₂SO₄, and a fixative was studied.     

Electrodeposition of a cobalt-molybdenum alloy from an ammonia-citrate electrolyte

Kinetics of processes of electrochemical production of a cobalt-molybdenum alloy out of an ammonia-citrate electrolyte is studied. The electrolyte’s composition is similar to that used for depositing a nickel-molybdenum alloy. It is established that the cobalt-molybdenum alloy undergoes deposition at smaller values of pH (5.0–6.0) than the nickel-molybdenum alloy (7.0–9.0). The current efficiency for the cobalt-molybdenum alloy is substantially dependent on the electrolyte pH, whereas the chemical composition of the obtained deposits is practically independent of the electrolyte pH in the pH interval 5.0–8.0 at current densities of 0.025 to 0.100 A cm^?2. On the other hand, a change in the electrolyte pH produces a considerable effect on the morphology of the obtained deposits. At large values of pH (pH 8.0), one can obtain a powder-like deposit of the cobalt-molybdenum alloy with a small value of the current efficiency. The deposits that are obtained in the pH region 5.0–6.0 have some cracks, with the number of cracks increasing with the electrolyte pH.     

Modeling of the solution composition and a study of the electrodeposition of the Cu-Zn alloy

Choice of ligands in development of new solution compositions for electrodeposition of alloys was simulated and the possibility of electrodeposition of the Cu-Zn alloy from a solution of gluconate complexes of ions of these metals was experimentally verified. The effect of various factors on the admissible current density of electrodeposition of high-quality Cu-Zn alloy coatings, brass composition, current efficiency by the alloy, and strength of brass adhesion to rubber was studied.     

Electrodeposition of a lead-indium alloy from an acetic electrolyte

Electrodeposition of a lead-indium alloy from an acetic electrolyte containing a “Drop VOX superactive oxygen” cleanser (technical specification 2383-063-14551353-05) as a surfactant was studied.     

A viscometric study of tuning micellar morphology by organic additives

The micellar morphology in aqueous 0.2 M sodium dodecyl sulfate (SDS) solutions has been studied in the simultaneous presence of organic salts (anilinium hydrochloride, AHC; ortho-toluidine hydrochloride, oTHC; para-toluidine hydrochloride, pTHC) and aliphatic alcohols (n-butanol, C₄OH; n-pentanol, C₅OH; n-hexanol, C₆OH; n-heptanol, C₇OH), aliphatic amines (n-butylamine, C₄NH₂; n-pentylamine, C₅NH₂; n-hexylamine, C₆NH₂; n-heptylamine, C₇NH₂), or hydrocarbons (n-hexane, C₆H; n-heptane, C₇H) by viscosity measurements under Newtonian flow conditions at 30 °C. Addition of alcohols and amines causes micellar growth which is found to be dependent upon chain length of the additive and nature of organic salt counterion. It is observed that amines are more effective in increasing the viscosity of the system if added in pure 0.2 M SDS solution, while SDS + pTHC system was found versatile when alcohols were added to this system. The increased viscosity or the micellar growth is explained in terms of the site of solubilization of the respective additive and the interaction of the additive with micellar surface and salt counterion present in the head group region. Hydrocarbons are nearly ineffective in inducing micellar growth and can be used as ‘micellar destroyer’ for the grown micelles. The additives used are found effective in tuning the environment of the micelle which is reflected in viscosity behavior. This work may find use in micellar ultrafiltration as well as in mimicking the natural cell, which has several aspects common with the micelle.     

A kinetic study of the seeded growth of barium sulfate in the presence of additives

The crystallization of barium sulfate seed crystals in supersaturated solutions has been studied conductometrically and radiochemically at 25°C. After an initial surge reflecting secondary nucleation, the crystal growth follows a rate law second-order in relative supersaturation, both in the absence and presence of additives. Organic polyphosphonates and polymeric molecules such as polygalacturonic acid and ethylenemaleic anhydride co-polymer are effective inhibitors of crystallization. The inhibiting influence of benzene polycarboxylic acids can be related to the tendency for complex formation with barium ions and to the pH of the supersaturated solutions.     

Effect of complexation of cadmium ions with N-methylpyrrolidone on kinetics of their electroreduction in sulfate electrolyte

Calculation of coordination numbers showed that N-methylpyrrolidone (N-MP) forms stable 1: 4 metal-ligand complexes in sulfate cadmium-plating electrolytes. Methods of computer simulation and quantum-chemical calculations allowed establishing that thermodynamically stable Cd(II) complexes formed in the bulk of the sulfate electrolyte contain, apart from four N-MP molecules, four water molecules that provide additional stabilization of the complex due to formation of hydrogen bonds between the ligands. Electrochemical studies indicate the predominant participation of Cd(II) complexes in the electrode reaction. Their discharge is preceded by their slow dissociation. Hindrance of the process of Cd²⁺ ion electrore-duction from complex electrolytes results in improvement of the structure and quality of cathodic cadmium deposits.     

Elecrodeposition of lustrous zinc coatings from sulfate electrolyte

Electrodeposition of lustrous zinc coatings from a sulfate electrolyte containing ZnSO₄, Na₂SO₄, buffer additives, and fixers (products of phenol-formaldehyde condensation) was studied.     

Electrodeposition of lustrous zinc coatings from sulfate electrolyte

The electrodeposition of lustrous zinc coatings from a sulfate electrolyte containing ZnSO₄, Na₂SO₄, buffer additives, and 2-butyne-1,4 diol was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 8, 2004, pp. 1284–1288.Original Russian Text Copyright © 2004 by Medvedev, Makrushin.     

Electrodeposition of iron-molybdenum alloy from ammonia-citrate electrolyte

Fe-Mo deposits were obtained from ammonia-citrate electrolyte at the potentials to the negative of -0.8 V (NHE). The method of X-ray photoelectron spectroscopy was used to establish that iron and molybdenum are included in the metallic form into the coating formed on the cathode. In the range of potentials of ?0.90 to ?1.10 V, the ratio between partial current densities of iron and molybdenum electrodeposition remains practically constant, which is the cause of independence of the chemical composition of the alloy on the current density in a wide range of potentials.     

Effect of concentration of ammonia and citrate ions on the kinetics of cathodic reactions during electrodeposition of a nickel-molybdenum alloy

The effect of the concentration of ammonia and citrate ions on the kinetics of cathodic processes in electrolytes intended for depositing electrolytic coatings of a nickel-molybdenum alloy is studied. Conditions conducive to obtaining coatings of satisfactory quality are formulated. The effect of ammonia and citrate ions on the Mo content in the alloy is analyzed. The experimental data are explained by assuming that the intermediate products of reduction of nickel and molybdate ions are adsorbed on the electrode surface.To the Centennial of B.N. Kabanov.Translated from Elektrokhimiya, Vol. 41, No. 1, 2005, pp. 83–90.Original Russian Text Copyright © 2005 by Kuznetsov, Pavlov, Chepeleva, Kudryavtsev.