Electric multicoloring of alkaline anodized alumina films by applying A.C current was investigated in aqueous amine solutions containing metallic salts and boric acid. The anodized films were colored uniformly in the baths containing diethanol amine or triethanol amine. Green colored films were obtained in a copper sulfate-triethanol amine bath. Blue, yellow, purple, and green films were obtained in a nickel sulfate-boric acid-triethanol amine bath. Brown colored films were obtained in a cobalt sulfate-boric acid-triethanol amine bath. The amine group was found to be present in the colored films by means of X-ray photoelectron spectroscopy. It was suggested that metal-amine complexes were deposited in the pores of the alumina films.

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The Guglielmi's two successive adsorption step model for the codeposition of inert particles from electroplating baths has been applied to the phenol resin particles/zinc system to elucidate deposition mechanism of the resin particles. It was found that the coverage of strongly adsorbed particles, calculated from the amount of particles contained in the composite films by using Guglielmi and Saifullin equations, is nearly equal to the fraction of the particles obtained from the SEM observation. The resin particles were initially adsorbed to the cathode by the electrophoretic effect. However, only the particles strongly adsorbed by the electrostatic force were embedded in the growing metal deposit, as shown in the Guglielmi's model. This is not the case when the bath is vigorously agitated. The amount of particles codeposition in the composite film depends on the probability of the collision of particles with cathode. A modified mechanism for the mechanical deposition of particles has been proposed.

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The amount of sulfuric acid in chromium plating solutions was determined by the use of a rapid and simple turbidimetric procedure for barium sulfate precipitated. Chromium (VI) oxide was reduced completely to chromium (III) with ethylalcohol before the turbidimetry. A wavelength of 700nm was used in the method, because the absorption of light by chromium (III) was less in this wavelength than in other wavelengths. The same sample solution containing no barium nitrate was used as the reference solution to eliminate interference with colored metal ions such as chromium (III), copper and nickel. The time required for the analysis was about 40 minutes for each sample. Analytical results for sulfuric acid in an actual chromium plating solution showed a very good agreement with the amount of the acid obtained by a gravimetric method.

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