Surface Optical Properties of Gold
Nanoparticles
by Emily K. Walker
Supervisors: Dr. Law and Dr. Sorensen
Kansas State University Physics Department REU Program, sponsored by NSF
Welcome to my webpage. This page summarizes my experience
doing research for summer 2008 with Dr. Bruce Law and Dr. Chris Sorensen.
Below, I describe the Project Goals, my Research Strategy, my Research Progress,
and have posted my Final Presentation .I post my homework assignments from our weekly REU
scientific Ethics class, taught by Prof. Bruce
Glymour and Prof. Amy Lara, and my reaction to Prof. Larry Weaver's Lectures. Scroll down to learn more About
Me. I have added some photos from my summer in Kansas. Finally, I've included
some Useful Links.
Project Goals: My goal is to determine some of the optical properties of
gold nanoparticles. I hope to find out whether they form a layer on the bottom
of the sample holder, or if all the changes are caused by a bulk effect. To do
this I will vary the concentration of the nanoparticle solution.
Research Strategy: I will collect data
using an ellipsometer and varying concentrations of gold nanoparticle solution to
determine the optical properties of gold nanoparticles. I am trying to
determine whether the particles remain in solution at high concentrations, or
if they fall to the bottom and create a layer. To determine which the case is,
I am using Python script to model the different situations and comparing my
data to those models. The nanoparticles are about 5 nm in diameter and are
suspended in a solution of tert-butyl toluene (tbt). Attached to these
nanoparticles are ligands which prevent the nanoparticles from clustering and
increase their size to ~7.4 nm. A schematic of my set-up can be found here. The ellipsometer measures ρ, the ratio between the p
and s directions of the polarization of the reflected light off the substance.
The p direction is that parallel to the surface, and the s is perpendicular.
Final Presentation: Click here to download
my presentation in PowerPoint.
About Me: I am currently a
rising junior physics major/optical engineering minor at Rose-Hulman
Institute of Technology. I am on the RHIT women’s lacrosse team and I am the Vice President of the Rose Astronomical
Society and historian for the Rose chapter of Circle K International. I enjoy physics (especially optics), dancing, playing the
piano, skiing, ice skating, singing, reading, doing community service, doing
crossword puzzle, and being clean. I hope one day to become a medical
physicist.
Useful Links:
Check out these useful sites:
American Physical Society
Statements on Ethics
Updated July 31, 2008
