A method for preparing a colloidal dispersion of precious metal nanoparticles free of organic adsorbates that have a molar weight above 100 g/mol, the colloidal dispersion of the precious metal nanoparticles obtained by the method according to the invention, solid and re-dispersed precious metal nanoparticles and products comprising colloidally dispersed or solid precious metal nanoparticles.

A colloidal brewing system has a transparent container assembly with a watertight bottom portion and an open top portion, the container assembly adapted to contain water. A removable lid electronic housing with two replaceable electrically charged silver rod members is disposed on a bottom portion of the lid member, the rod members extending substantially to near the bottom of the container assembly. A magnetic stir assembly substantially centers an interior bottom portion of the container assembly and to rotate, in the water, on a parallel plane to the bottom portion. A receiver and transmitter coil assembly are disposed within a base container assembly, the base container assembly designed to gravitationally support the watertight bottom portion of the transparent container assembly, the receiver coil and transmitter coil assembly inductively coupled to the magnetic stir assembly. The inventive concept has a rechargeable battery, a control panel, power port members, and handle member.

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.

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.