Surfactant (PEG 400) effects on crystallinity of ZnO nanoparticles

AbstractThe surfactant effects on the size and crystallinity of ZnO powders prepared by Solid-state mechanochemical method. The present method is a simple and efficient method for the preparation of nanoparticles with high yield at low cost. The size and crystallinity of the nanoparticles were analyzed by X-ray diffraction, scanning electron microscopy and energy-dispersive spectrometer (SEM/EDAX). Optical properties and band gap were studied by UV–Vis spectroscopy. XRD shown that the lattice constants have been changed to some extent. These results showed that the band gap energy decreases with increase in lattice constants, which can be attributed to the improvement in crystallinity of the samples. The band gap of the ZnO can be tuned in the range of 3.37–3.33eV respectively, by the use of PEG 400 surfactant

Electrochemical and reflectance studies of bright Zn-Co alloy coatings

91-95In the present work, electrodeposition of Zn-Co alloy from sulphate bath has been carried out in presence of brightener, the condensation product of vanillin and serine. The investigation on electrodeposit has been carried out using cyclic voltammetry and galvanostatic techniques, while polarization and electrochemical impedance spectroscopic techniques are used for corrosion studies. It is found that the deposition current density has a great influence on the corrosion resistance nature of the coatings. The reflectance and scanning electron microscopic studies show the formation of bright coatings

A new brightener for zinc plating from non-cyanide alkaline bath

318-323Zinc electrodeposition from non-cyanide alkaline solution was carried out in presence of salicylaldehyde, a new brightener. The bath constituents and bath variables were optimized through standard Hull cell experiments. Current efficiency and throwing power of the developed bath were measured. Polarization study revealed the shifting of potential towards more cathodic direction in presence of addition agents. Corrosion resistance test on zinc coated steel revealed good protection of the base metal by the zinc coating. SEM photomicrographs of the deposits showed fine-grained crystal growth in the presence of salicylaldehyde. The consumption of brightener was 0.4 mLL-1 for 1000 A-h

Effect of condensation product on bright zinc electrodeposition from sulphate bath

390-395Zinc electroplating is carried out in presence of condensation product formed between -Alanine and Glutaraldehyde. The bath constituents are optimized through Hull cell experiments. Operating parameters such as pH, temperature, current density are also optimized. Current efficiency and throwing power are measured. Polarization study reveals high shift of potential towards negative direction in the presence of addition agents. Corrosion resistance test indicated good protection of steel by the coating. IR spectrum of the deposit shows the inclusion of the compound. SEM photomicrographs show fine grained deposit in the presence of addition agent. The consumption of brightener in the lab scale is 8 mL for 1000 amp-hour

Study of Schiff’s bases as surface modifiers for corrosion protection of copper in sulphuric acid

16-21Surface modification of copper by newly synthesised Schiff’s bases, N- [(1E)-2-furylmethylene]-N-phenylamine (FA), 3-{[(1E)-2-furylmethylene] amino} phenol (FAP), 4-{[(1E)-2-furylmethylene] amino} benzoic acid (FAB) and 2-{(E)-[(3-hydroxyphenyl) imino] methyl} phenol (SAP), in 0.5 M sulphuric acid solution was investigated. The corrosion behavior of surface treated copper specimens was tested by galvanostatic polarization technique. The effect of concentration of Schiff’s bases in the treatment bath, treatment time and temperature of the corrosive medium on the corrosion protection efficiency of Schiff’s bases was investigated. Among the compounds studied, the protective film formed by FAB showed maximum protection efficiency. The inhibitive action of Schiff’s bases was due to their adsorption and consequent growth of the protective film on the metal surface. The inhibitive effectiveness depended strongly on the molecular structure of the Schiff’s base. The interaction of the compounds with the metal surface was confirmed by FTIR technique. The SEM studies showed the modification of copper surface due to the adsorption of Schiff’s bases

A study on brightening property of newly synthesized compound in electroplating of zinc-nickel alloy

155-162The electrodeposition of zinc-nickel (Zn-Ni) alloy from chloride bath was carried out in presence of condensation product formed between thiamine hydrochloride (THC) and furfural (FFL). The bath constituents were optimized through Hull cell experiments. Operating parameters such as pH, temperature and current density were also optimized. Current efficiency and throwing power were measured. Polarization study revealed shift of potential towards negative direction in the presence of addition agents. Corrosion resistance tests revealed good protection of base metal by Zn-Ni alloy deposit. SEMs showed fine-grained deposit in the presence of condensation product. FTIR spectrum of the scrapped deposit showed the inclusion of condensation product in the deposit during plating. The consumption of brightener in the lab scale was 5 mLL⁻¹ for 1000 amp-h

Influence of condensation product on electrodeposition of Zn-Mn alloy on steel

29-35Electrodeposition of zinc-manganese alloy was attempted from sulphate bath containing condensation product (CP) of furfuraldehyde (FRL) and L-lysine monohydrochloride (LL). The effect of bath constituents, pH, current density and temperature on nature of deposit was studied through Hull cell experiments. The throwing power was measured using Haring and Blum cell. The bath constituents and operating parameters were optimized. Deposit properties and corrosion resistance were discussed. Current efficiency and polarization studies were carried out. SEM photomicrographs of the deposit obtained from optimum bath revealed that the condensation product modifies the morphology of zinc-manganese alloy deposit. IR spectrum of the scrapped deposit showed inclusion of addition agent