How Surface Interactions Affect Adsorbed Polymers Frank D. Blum, Missouri University of Science and Technology, DMR 0706

1. How Surface Interactions Affect Adsorbed PolymersFrank D. Blum, Missouri University of Science and Technology, DMR 0706197 Thin layers of polymers adsorbed on surfaces behave differently than those in bulk. The properties of a material like poly(methyl methacrylate) (PMMA, as in PlexiglasTM) attach to metal oxide surfaces through hydrogen bonding. Hydrogen bonds can be observed using infra-red (IR) spectroscopy and their effects noted using thermal analysis or nuclear magnetic resonance (NMR) spectroscopy. Bulk PMMA has an adsorption band at about 1730 cm-1 for the carbonyl stretch. On normal silica, PMMA has an additional band, at around 1712 cm-1, due to carbonyls hydrogen bonded to silica. Many PMMA segments are tightly bound in this way and result in higher glass transition temperatures (Tg's) for the adsorbed polymer. When silica is treated with methyl groups (as in TS530), adsorbed PMMA shows few bound carbonyls and, consequently, higher Tg's are not observed. Infra-red spectra of PMMA in bulk (bottom), on silica (M5, top), and treated silica (middle). M. T. Kabomo, F. D. Blum, S. Kulkeratiyut, S. Kulkeratiyut, P. Krisanangkura, J. Polym. Sci.: B: Polym. Phys., 46, 649–658 (2008).

2. How Surface interactions Effect Adsorbed PolymersFrank D. Blum, Missouri University of Science and Technology, DMR 0706197 The behavior of small amounts of polymers on surfaces is important in many applications - from advanced composites to gas sensors. Research funded by this award has trained graduate students, undergraduates and high school students. In the summer of '08, high school students Mark Hickle and Amy Jackson, and undergraduate Jacqueline Burgher used infra-red spectroscopy and thermal analysis to study adsorbed polymers. Five graduate students are also working on different aspects of this project. High school students Amy Jackson, and Mark Hickle, and undergraduate Jacqueline Burgher