STUDY OF METAL COLLOIDS PRODUCED BY MEANS OF GAS EVAPORATION TECHNIQUE. I. PREPARATION METHOD AND OPTICAL PROPERTIES IN ETHANOL.

Abstract

Three new methods for the preparation of metal colloid in organic solvent are presented. These methods were the matrix isolation method, the gas flow-cold trap method and the gas flow-solution trap method; the latter was found to give a good colloid solution for the optical measurements. The metals reported are high purity Ag, Au, Cu, In, Al, Ca, Sn, and Pb. The stability of the colloid is dependent on the kind of metals: Al, In, Au, and Ag are stable, and Pb, Sn, Ca, and Cu are unstable. The optical absorption spectra of these sols were measured in ethanol solution in Ar atmosphere. They are discussed in relation to those reported on the solid matrix or on the solid substrate.