Department of Chemistry Eric Senning and James Utterback, Mentors The Dynamics of the Glass Transition Studied by Molecular Fourier Imaging Correlation Spectroscopy By Sametra Delaney University of Oregon Department of Chemistry Andrew H. Marcus, Ph.D., PI Eric Senning and James Utterback, Mentors Summer 2008 SPUR Student

Motivation Understanding the Mechanism behind the Theory of the nature of glass and the glass transition

Contribution To Other Areas of Science? . Pharm-make a glass stable structure instead of crystalline form, allowing quick dissolving and to be taken orally

Physical Properties of Glass Liquid State Solid State Trapped between being a liquid and solid because it contains different regions

Glass Solid Phase of a material with no long range molecular order disordered molecular structure of a liquid and the rigidity of a solid

Glass Transition . The molecules in some regions jam quickly, while in other regions move in a liquid like fashion

Materials and Methods Fluorescently doped thin polymer films MFICS Using polymer films

Studied Materials Poly (methyl methacrylate) PMMA Poly (vinyl acetate) PVAc We begin with synthetic polymers. dissolve in THF(tetrahydrofuran) to give 5%conc, add solution to polar solvent, dry overnight, freeze dry polymer in THF to remove water/methanol. (twice) filter for particulate matter

Glass Transition Polymer Sample Compression Molder Once polymer is purified, freeze dried twice, and filtered again. Compression molding. The polymer is melted and then cooled above the Tg state. The torque is used to apply pressure during this process.

Results Dyed Samples (with bodipy) and their respective blanks

Molecular Fourier Imaging Correlation Spectroscopy Red beads are the fluorescent probes. MFICS detects the phase of the probes by transmitting a beam through the sample. Green beam light is absorbed and red beam light is emitted (fluoresced). Depending on the position of the particle the interference pattern creates the waveform of the red emitted light. Red comes from red fluorescent light on beads Amplitude is large and phase = 0 Amplitude is small and phase = π

Autocorrelation of phase and amplitude

Discussion The dynamical process of the glass transition is yet to be understood, however, with the result of successful polymer samples, and the capabilities that the Marcus lab and MFICS have to offer, this question is sure to be answered.

Acknowledgements Andrew H. Marcus, PhD James Utterback Eric Senning This work was supported by UO Spur program and FASEB MARC

A. Marcus, M. Knowles, T. Grassman A .Marcus, M. Knowles, T.Grassman. Structure and Dynamics of fluorescently labeled complex fluids by Fourier Imaging Correlation Spectroscopy 2000 M. D. Ediger, C.A Angell, and S. R. Nagel, J.Phys.Chem. 1996 J.Utterback. Imj.9-10 2008 Ian Harsey. Imj. 11-12 2008