Determination of Oxides on the Surface of Copper Powders by an Acid Dissolution Method -Study on Metal Powder-Polymer Composite Materials. I.-

Abstract

In order to determine the amount of copper oxides on the surfaces of copper powders, an acid dissolution method was investigated. After the addition of copper powders to a 0.1mol·dm^-3-HCl H₂O-EtOH solution (50/50 by v/v, 200ml) containing octylamine (0.1g)followed by the dissolution of copper oxides on the surfaces into the solution for a period of 5 min, the dissolved copper ions were determined by an atomic adsorption technique and the amount of copper oxides was calculated. The most significant points for the acid dissolution method are to inhibit the reoxidation of surfaces of copper powders by complete removal of oxygen from the measuring flask, the addition of inhibitors to the solution and the use of organic solvents which are an inert solvent to tile oxidation of copper. The present method is applied to the determination of the amotint of copper oxides on the surface of copper powders of an average grain size of more than about 2.5 μm.