METHOD OF PRODUCING SILVER NANOPARTICLES Russian patent published in 2010 - IPC C01G5/00 B82B3/00 

FIELD: chemistry.

SUBSTANCE: silver nanoparticles are obtained through reduction of its salts from a solution in gel sulfo cation-exchange matrix KU-2-8. The silver salt used is 0.01 M AgNO₃ solution. The neutral reducing agent used is a 2-3 times diluted 6% hydrazine solution in a 2.5% solution of sodium hydroxide which is poured in proportion to a matrix pre-saturated with silver ions. The cationic reducing agent used is 0.1 M solution of tin (II) chloride in a 1.6 M solution of hydrochloric acid which is first brought into contact with an ion-exchange matrix for 10-15 minutes. Excess SnCl₂ is then washed off the matrix by passing distilled oxygen-free water in dynamic conditions in ratio of 1:20 at a rate of 5 m/h. After that a solution of silver nitrate is passed in a 10 M ammonia solution in ratio of 1:5 at a rate of 2 m/h. After synthesis the matrix is successively washed with oxygen-free and deionised water in ratio of 1:20 and a 6% solution of oxygen-free sulphuric acid in ratio of 1:5. The silver particles have average size of 70-85 nm when a hydrazine solution is used and 25-40 nm when SnCl₂ is used.

EFFECT: invention enables to obtain spatially distributed and aggregatively stable silver nanoparticles matrix-insulated in strongly acidic styrene-divinylbenzene sulfo cation-exchange gel without its mechanical deformation.

3 cl, 2 ex