A method includes heating a sulfonated polyester resin in an organic-free solvent, adding a solution of silver (I) ion to the heated resin in water to form a mixture, reducing silver (I) to silver(0) by heating the mixture from about 65° C. to about 90° C., thereby forming an emulsion of composite particles comprising a sulfonated polyester matrix and a plurality of silver nanoparticles disposed within the sulfonated polyester matrix, and allowing the silver nanoparticles to agglomerate into a silver nanodendrite structure.