Electrophoretic Concentration of Nanoparticles of Gold in Reversed Micellar Solutions of AOT

Abstract

The electrophoretic mobility of nanoparticles of gold in reversed micelles of AOT was determined, and the nanoparticle electrokinetic potential was calculated. The electrokinetic potential of the particles decreased from 43 to 17 mV with the fall in the solubilization capacity from 1 to 0.2 vol. %. Correspondingly, the hydrodynamic radius decreased from 2.9 to 1.8 nm. On the basis of the electrokinetic studies, a new concentration method was developed, allowing concentration of metal particles with an enrichment factor of ∼10 3 . A simple model of the concentration has been proposed as a process of electrophoretic separation of micelles with gold nanoparticles from the empty ones. The limiting gold concentration in the liquid cathode concentrate (∼1 mol/L) and the concentrate volume have been calculated depending on the organic-phase volume, the solubilization capacity of the micellar solution, and the initial metal ion concentration.

Di-(2-ethylhexyl) dithiophosphoric acid surface protected gold nanoparticles: micellar synthesis, stabilization, isolation, and properties

“…During the reduction of Au III and Ag I by hydrazine in AOT micelles, the charge of Au and Ag NPs is positive, too, and it increases with the dilution of AOT solution in decane by chloroform [14,38]. On the basis of the results reported in the present work and those obtained previously, we can propose the following hypothetical mechanism of double sequential stabilization.…”

“…Among a number of the methods of their preparation, rather widespread one is chemical reduction of gold species in solutions including homogeneous [6,7], heterogeneous [8][9][10], and colloidal [11,12] systems. Synthesis in reverse micelles is one of the efficient methods of obtaining nanoparticles with a narrow size distribution due to the possibility of purposeful adjustment of micelle structure through dosed solubilization of the disperse aqueous phase (DAP) [12][13][14][15].…”

Characterization of CdSe nanocrystals coated with amphiphiles. A capillary electrophoresis study

“…surfactants) was related to particles electrophoretic mobility, which can a sign of complexity in the nanoparticles/CE system. Issued last works [ 34 , 35 ], dealing with nanoparticles dispersed in solution of reversed micelles, show that effects: nanoparticles separation, enrichment for charged nanoparticles and coagulation, can be explained by DLVO theory (Deryaguin-Landau-Verwey-Overbeek).…”

Determining the hydrodynamic radii of AOT micelles with silver nanoparticles by means of photon correlation spectroscopy

“…An electrophoretic concentrate of silver nanoparti cles was obtained in the following manner [12]: After the synthesis of nanoparticles, a micellar solution of AOT was placed into a rectangular glass cell equipped with planar parallel copper electrodes with an area of 16 cm 2 and an interelectrode gap of 0.5 cm. Electro phoresis was performed for 30 min with an electrical voltage of 300 V applied to the electrodes.…”