Electrochemical redn. of metal salts to form colloids for optical and electronic use, etc.

摘要

Electrochemical prepn. of metal colloids with a particle size less than 30 nm is claimed. One or more metals are cathodically reduced in the presence of a stabiliser in organic solvents or in solvent mixts. contg. organic solvents and/or water at -78 to 120 deg C to form metal colloidal solns. or redispersible metal colloid powders. Opt. a supporting electrolyte may be added and opt. the redn. may take place in the presence of inert substrates and/or soluble metal salts of the respective metals. The metals may be of gps. Ib, IIb, III, IV, V, VI, VIIb, VIII, lanthanoids and/or actinoids of the periodic table. Also claimed are the colloids prepd. by the above method. Also claimed are metal colloids, bimetallic colloids or multi-metallic colloids having particle sizes up to 30 nm stabilised by the presence of water-soluble stabilisers, partic. cationic, anionic, betainic or nonionic stabilisers. Also claimed are substrates coated with mono-, bi or multi-layers of the colloids.