Welcome to Kelly Malone's Homepage!

I am currrently pursuing a Ph.D. in Chemistry at Auburn University, specializing in Physical Chemistry.

My research is focused in colloid science.  Specifically, the formation of metal colloids in gel, or glass matricies.  Currently, I am working on the reversible formation of gold particles in polymeric gels of diallyldimethylammonium chloride (DADMAC).  I am also working on forming gold particles in Vycor glass.  Specific details are given below:

I. Reversible Formation of Gold Nanoparticles in Gel Matricies

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This photo shows the gold particles within the gel matrix.  These are formed  first by swelling a crosslinked polymer of DADMAC with a methanolic solution of Au(III).  The Au(III) acts as a chromophore when exposed to UV light of wavelength 350nm. The solvent acts as the electron donor.  The process occurs in two steps.  In the first step, the chromophore is photoreduced to form Au(I).  The sample is bleached during this step.  The transition from yellow (Au(III)) to colorless (Au(I)) is followed using UV-Visible spectroscopy.  The next step involves further reduction of Au(I) to form metallic gold, upon continued irradiation.  Through photonic efficiency calculations, it was found that the reduction of the chromophore involves a chain process, and the formation of particles involves a biphotonic process.  Both processes were found to follow apparent zero-order rate laws. 
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Once light is removed from the system, the particles are oxidized to reform the original Au(III) complex.  In approximately 48 hours, the red particles are oxidized and the sample is clear, forming Au(I).  In a second step, the sample slowly becomes yellow, indicating the reformation of Au(III).  This process takes approximately 14 days.       Next

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