Preparation, characterization, and surface modification of silver particles

Colloidal silver has been formed either by irradiation with 253.7 nm lighter by chemical reduction of AgClO4 in the presence of protective agents such as poly(vinylpyrrolidone), carboxy methyl cellulose, and gelatin. The particles were characterized by their absorption maximum and transmission electron micrographs. Peptization effect was observed in the presence of photosensitive benzophenone. Surface modification studies of silver particles in the presence of various complexing agents, viz., N-(hydoxyethyl)-ethylenediaminetriacetic acid, iminodiacetic acid, nitrilotriacetic: acid, 2-mercaptobenzimidazole, benzo-triazole, 5-aminotetrazole, imidazole, and sanazole were carried out and it was shown that the reactivity of silver particles increases in their presence. However, in the presence of stabilizers, due to competitive reactions, partial recovery of the surface plasmon absorption band was observed. The Fermi potential of surface modified silver particles seems to lie in the range of -0.40 +/- 0.05 V.