Synthesis and agglomeration of gold nanoparticles in reverse micelles

Abstract

Reverse micelles prepared in the system water, sodium bis-(2-ethylhexyl) sulfoccinate (AOT), and isooctane were investigated as a templating system for the production of gold nanoparticles from Au(III) and the reducing agent sulfite. A core-shell Mie model was used to describe the optical properties of gold nanoparticles in the reverse micelles. Dynamic light scattering of gold colloids in aqueous media and in reverse micelle solution indicated agglomeration of micelles containing particles. This was verified theoretically with an analysis of the total interaction energy between pairs of particles as a function of particle size. The analysis indicated that particles larger than about 8 nm in diameter should reversibly flocculate. Transmission electron microscopy measurements of gold nanoparticles produced in our reverse micelles showed diameters of 8-10 nm. Evidence of cluster formation was also observed. Time-correlated UV-vis absorption measurements showed a red shift for the peak wavelength. This was interpreted as the result of multiple scattering and plasmon interaction between particles due to agglomeration of micelles with particles larger than 8 nm.

Synthesis and characterization of gold nanorods and their application for photothermal cell damage

“…Spherical gold nanoparticles of size 8-18 nm can be prepared in AOT 0.1 M. 25,26 With the increased concentration of surfactant, the spherical shape is distorted and the aggregate becomes prolate-shaped. …”

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

“…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].…”

Evaluation of colloidal stability, kinematic viscosity and flash point of B10 Diesel/Biodiesel blends using nanostructured additives based on Al2O3 and oleic acid

“…Osmotic forces depend on the free energy of the solvent-ligand interactions because of the ligand molecules solvation, while the elastic forces are the result of entropy lost due to compression between the ligand chains and the surface of adjacent particles (Park, Y., Huang, R., Corti, D., & Franses, E., 2010). Osmotic repulsion and elastic force can be estimated as follows (Barrera et al, 2009), (Herrera, Resto, Briano & Rinaldi, 2005) Based on the mentioned model, a total interaction energy analysis was developed to evaluate the feasibility of the suspension process of alumina nanoparticles in the organic B10 media.…”