ANALYSIS OF COLLOIDS .6. SEMICONDUCTOR COLLOIDS OF HIGH MONODISPERSITY BY PREPARATIVE SIZE-EXCLUSION CHROMATOGRAPHY

The recently described method of size exclusion chromatography (SEC) of very small colloidal semiconductor particles was transferred from the analytical scale to the preparative one. The particular difficulties dealing just with SEC and the special situation when working with inorganic colloids are described. The influence of flow rate, sample volume, sample concentration and fraction volume were studied using CdS-sols with particle diameters ranging from 2nm to 8nm. Up to 200mg samples were separated in less than one hour. The fractions were generally characterized by analytical SEC and in two instances by transmission electron microscopy showing excellent consistency and standard deviations down to 11%.