Separating excess surfactant from silver and gold nanoparticles in micellar concentrates by means of nonaqueous electrophoresis

It is shown by physicochemical means (IR Fourier spectroscopy, CHN-analysis with preliminary sorption of surfactant on SiO₂) that the content of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in an electrophoretic concentrate remains unchanged during the electrophoretic concentration of silver and gold nanoparticles. Diluting the concentrate and carrying out the second stage of electrophoresis reduces the concentration of surfactant from 0.25 to 0.015 M while maintaining the mass concentration of nanoparticles. Nanoparticles in organosols before and after electrophoresis are characterized by means of photon correlation spectroscopy, phase analysis light scattering, and spectrophotometry. Conducting films on glass substrates are obtained from concentrates with a different contents of surfactant via water-alcohol treatment and thermolysis.