Introduction to AOT Nanoreactors for the Synthesis of Gold Nanoparticles

Date of Graduation

Fall 2005

Degree

Master of Science in Materials Science

Department

Physics, Astronomy, and Materials Science

Committee Chair

Robert Mayanovic

Abstract

The purpose of this project was to develop a process of growing gold nanoparticles in Aerosol OT (AOT) reverse micelles at Missouri State University. The tertiary system of water, AOT, and n-heptane was chosen to conduct the experiment in the largely unexplored region of the tertiary system that consists of the coexistent liquid+liquid/n-heptane phase. The concentrations of water, AOT and n-heptane were calculated to be well within this range of the ternary phase diagram. Silicon wafers, one submerged in the mixture and one suspended in the air above the mixture, were examined using the atomic force microscope (AFM), in the topography, differential phase, and electrostatic (EFM) mode. It was determined that both wafers had gold nanoparticles with sizes (̃70 nm and ̃80 nm radius for submerged and evaporated samples, respectively) close to the expected value of ̃85 nm in radius. Additional gold nanoparticles were grown in AOT/n-heptane/water solution well within the reverse micelles in oil region of the ternary phase diagram. UV-VIS absorbance spectra measured from this solution showed two distinct peaks at 520 nm and 720 nm, where the former is identified with the transverse plasmon resonance and the latter the longitudinal plasmon resonance.

Keywords

nanoparticles, AOT, gold, reverse micelles, nanoreactors, n-Heptane

Subject Categories

Materials Science and Engineering

Copyright

© David J. Arrant

Citation-only

Dissertation/Thesis

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