PROCESS FOR PREPARING NANO-SIZED SILVER COLLOID IN ORGANIC SOLVENTS

• Main Authors: AN, KI SEOK, LEE, SANG HYUN, SUNG, KI WHAN, KIM, CHANG GYOUN, CHUNG, TAEK MO
• Format: Patent
• Language: English
• Published: 15.11.2006
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; INORGANIC CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

A process for preparing a nano-sized silver particle colloid dispersed into organic solvents is provided to prepare silver nanoparticles with several nanometer particle size and uniform particle distribution by overcoming an existing problem in restrictively synthesizing silver nanoparticles in an aqueous solution, and prepare a stable silver colloid by dispersing the silver nanoparticles into various organic solvents. A process for preparing a nano-silver colloid monodispersed into organic solvents comprises the steps of: (a) mixing a silver salt or an aqueous silver salt solution with a covering ligand dissolved into an organic solvent; (b) slowly adding a reductant to the mixed solution; (c) precipitating nanosilver particles in a polar organic solvent, and separating the nanosilver particles; (d) dispersing prepared nanosilver particles into a non-polar organic solvent, and adding a dispersant to the solution. The covering ligand is formed of a nonionic, cationic, anionic or amphoteric hydrocarbon-based compound having solubility in the organic solvent, or a mixture of two or more thereof. The silver salt is selected from silver acetate, silver nitrate, silver carbonate, and silver perchlorate. The reductant is selected from sodium borohydride, hydrazine, lithium borohydride, lithium aluminumhydride, or citrate.