Preparation of highly stable concentrated dispersions of silver nanoparticles using synergistic dispersing agents
AssigneeNOBEL/Noble Elements/LLC
InventorDan Goia
Life of this patent
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Abstract
Methods for preparing highly stable concentrated dispersions of silver nanoparticles and described herein. Contemplated methods comprise combining a selected polysaccharidic dispersant with a selected non-reacting dispersant to yield concentrated silver dispersions with enhanced stability and lowered undesirable residual organics. Contemplated methods further comprise selecting an appropriate source of silver ions to reduce the ionic strength of the reaction medium and final silver dispersions.
Claims20
A method of producing a highly stable concentrated dispersion of silver nanoparticles, comprising the steps of:
- adding a silver compound in deionized water to form a first mixture;
- separately from the steps of adding silver compound in deionized water, dissolving a combination of a reducing dispersant and co-dispersant in deionized water to form a first solution, wherein the co-dispersant is sodium alginate;
- combining the first mixture and the first solution to form a slurry;
- mixing the slurry with a basic solution to form an alkaline basic slurry;
- and
- heating the alkaline basic slurry to yield highly uniform silver nanoparticles wherein no silver nanoparticle is larger than 25 nm.
A method of producing a highly stable concentrated dispersion of silver nanoparticles, comprising the steps of:
- adding a silver compound in deionized water to form a first mixture;
- separately from the steps of adding silver compound in deionized water, dissolving a combination of a reducing dispersant and co-dispersant in deionized water to form a first solution;
- wherein the co-dispersant is sodium alginate,
- combining the first mixture and the first solution to form a slurry;
- mixing the slurry with a basic solution to form an alkaline basic slurry;
- and
- heating the alkaline basic slurry to yield highly uniform silver nanoparticles wherein no silver nanoparticle is larger than 25 nm, wherein the co-dispersant is present at a concentration of less than 1/8 a concentration of the reducing dispersant.
A method of producing a highly stable concentrated dispersion of silver nanoparticles, comprising the steps of:
- adding a silver compound in deionized water to form a first mixture;
- separately from the steps of adding silver compound in deionized water, dissolving a combination of a reducing dispersant and co-dispersant in deionized water to form a first solution;
- wherein the co-dispersant is sodium alginate,
- combining the first mixture and the first solution to form a slurry, wherein the volume of the first mixture is between 1.5-2.5 the volume of the first solution;
- mixing the slurry with a basic solution to form an alkaline basic slurry;
- and
- heating the alkaline basic slurry to yield highly uniform silver nanoparticles wherein no silver nanoparticle is larger than 25 nm.
Dependencies are inferred from the claim text.