Patent ID: 7128816

Claim:
A method for producing a colloidal dispersion of nanoparticles of at least one conductive material in a dense fluid medium, the method comprising the steps of: (a) providing a reaction vessel for containing the dense fluid medium; (b) charging the dense fluid medium into the reaction vessel; (c) providing a rotatable first electrode comprising a first conductive material and terminated in a ceramic pin-array holder, the rotatable first electrode having (i) an end piece with a planar surface and (ii) an array of pins mounted in the pin-array holder and the planar surface; the first electrode immersed within the dense fluid medium; (d) providing a static second electrode comprising a second conductive material and having a planar surface, the second electrode immersed within the dense fluid medium and being near to the first electrode; (e) rotating the first electrode such that the dense medium is circulated between the first and second electrodes; and (f) imposing an electric potential between the rotating first electrode and the second electrode to create electrical discharges between the pins and the planar surface of the second electrode, the electric potential being sufficiently high to dislocate nanoparticles of at least one of the first conductive material or the second conductive material from the respective electrode.