NEEDLE-TYPE COLLOIDAL COPPER (II)HYDROXIDE PARTICLES

Stable dispersions of fine (< 0.05-mu-m) needle-type copper(II) hydroxide particles were prepared at room temperature by admixing sodium acetate and ammonia to copper sulfate solution. The particle length and width could be altered with the concentration of reactants. The rate of dissolution of copper(II) hydroxide particles in doubly distilled water at room temperature is time dependent, which is due in part to the formation of a mononuclear complex solute (CuOH+). After extended times (e.g., 18 h), the particles underwent phase transformation, resulting in longer needless of higher degree of crystallinity.