Student Project Abstracts 2005 - Pluto - University of Washington

DZIENISACKNOWLEDGEMENTSSTC-MDITR, Summer 2005 REU – “Hooked on Photonics,”NSF, COPE, Georgia Institute of Technology, Dr. Joe Perry,Wojtek Haske, Perry Research GroupGraph (g) - Absorption spectra of Ag 1:1 (OT:DT) nanoparticlefilms in polystyrene. The weight ratio of nanoparticles wasdecreased by ½ for every sample from sample 1 to sample 4.REFERENCES[1] T. Shimizu, T. Teranishi, S. Hasegawa, M. Miyake, J. Phys.Chem. B 2003, 107, 2719-2724.[2] X.M. Lin, C.M. Sorensen, K.J. Klabunde, Journal of NanoparticleResearch 2: 157-164, 2000.tered with 0.2µm filters) in polystyrene were prepared with variousweight ratios, (Graph f and g nanoparticle ratios decreased by½ for each solution).In both cases a blue shift in the absorption peak was observedwhen the nanoparticle concentration was lowered. The Ag 1:1spectrum also shows a shoulder around 400nm.CONCLUSIONCompleting the digestive ripening process under an argonflow shows many improvements to the Au nanoparticles. Theseimprovements include a more uniform size and better solubilityof the Au nanoparticles. The effect of digestive ripening on Ag3:1 (OT:DT) nanoparticles was not as beneficial. After digestiveripening, the Ag nanoparticles were no longer soluble and only aslight change in their size range was seen.For Au (DT) and Ag 3:1 (OT:DT) in various solvents, no majorshifts in the surface plasmon band was seen.When particles are placed in a polymer matrix a red shift of surfaceplasmon resonance occurs. When Ag 3:1 (OT:DT) nanoparticleswere placed in various polymers, there were differences inthe size and shape of the absorption spectra. These differencesmight be due to the different arrangements the nanoparticleshave in the different polymers, and the possibility of aggregatesforming could have varied depending on the polymer structure.Additionally, the local environment around the nanoparticles indifferent instances could affect the plasmon resonance. A blueshift occurs when the concentration of nanoparticles to polymeris lowered, which might be due to interactions between nanoparticles.Additional investigations are needed to provide further insightinto these findings. Investigation of the digestive ripeningof Ag nanoparticles in various solvents will be conducted to seeif control of the size distribution of the nanoparticles can be obtained.Also, X-ray diffraction studies of the nanocomposite filmswill be performed to investigate the arrangement of nanoparticlesin the polystyrene matrix.Krystle Dzienis is currently studying Materials Science and Engineering,specializing in polymers at the Pennsylvania State University. She is planningon continuing her education in the field of Materials Science by going on tograduate school upon completing her undergraduate degree in May 2007.CMDITR Review of Undergraduate Research Vol. 2 No. 1 Summer 2005 33