Copper hydrous oxide sols of uniform particle shape and size

Abstract

Conditions which lead to the formation of copper (I) and copper (II) hydrous oxide dispersions of uniform size and shape are described. Reduction of copper (II) tartrate complex by glucose yields stable sols of copper(I) oxide whose particle size is strongly dependent on the concentration of the reactants. All particles show cubic crystal symmetry characteristic of Cu 2O, although their habit changes from cubic, through cuboctahedral to octahedral as the average particle size increases. The sols can be prepared with size distributions sufficiently narrow to exhibit higher order Tyndall spectra (HOTS). For cuboctahedral particles, which quite closely resemble spheres light scattering leads to particle size distributions in fairly good agreement with electron microscope data. Copper (II) hydrous oxide dispersions were prepared by aging copper sulfate solutions at elevated temperatures and under controlled pH conditions. Sols of various particle shapes and uniformity were obtained depending on the experimental conditions.