Journal of the electrochemical society vol:147 issue:1 pages:198-202
The influence of the hydrophobicity of silica particles on the electrodeposition of Cu-SiO2 composite coatings from acid copper sulfate solutions on rotating disk electrodes was studied. Spherical, nearly monodisperse hydrophilic and hydrophobic silica particles were used. The hydrophilic silica particles were prepared by the Stober process. These particles were made hydrophobic by a treatment with oligodimethyl siloxane-alpha,omega-diol. The effect of ceryl trimethyl ammonium hydrogen sulfate (CTAHS) and sodium 1-dodecane sulfonate on the codeposition behavior was investigated. Hydrophilic silica did nor codeposit from surfactant-face nor from surfactant-containing acid copper sulfate solutions, but up to 4 wt % (congruent to 14 vol %) of hydrophobic silica codeposited from solutions containing 15 g/L of silica particles and 10(-4) M CTAHS. The codeposition rate of hydrophobic silica slowly decreased with time. The amount of codeposited particles was highest for a current density of 5 A/dm(2) and a rotation speed of 400 rpm. (C) 2000 The Electrochemical Society. S0013-4651(99)01-044-7. All rights reserved.