Emulsion Synthesis and Electrophoretic Concentration of Gold Nanoparticles in Sodium Bis(2-Ethylhexyl) Sulfosuccinate Solution in n-Decane

Abstract

Organosols of gold nanoparticles are obtained by hydrazine reduction of a chloroauric acid solution in a dynamic emulsion of water in n-decane stabilized with a surfactant, sodium bis(2-ethylhexyl) sulfosuccinate. The gold nanoparticles are characterized by phase analysis light scattering, photon correlation spectroscopy, transmission and scanning electron microscopy, X-ray phase analysis, spectrophotometry, thermal analysis, and elemental analyses. The hydrodynamic diameter (≈8 nm), electrophoretic mobility (3.9 × 10^–10 m²/(V s)), and electrokinetic potential (30 mV) of the synthesized particles are determined. A liquid-phase concentrate of nanoparticles is separated from the organosol by nonaqueous electrophoresis. Hydrophobic electrically conducting films with a contact angle of 115° and a specific resistance of 0.41 Ω/mm² are obtained by the thermal treatment of the concentrate.