COLL 427 |
| Robert A. Walker, Department of Chemistry and Biochemistry, University of Maryland, College Park, Building 091, College Park, MD 20742 and Okan Esenturk, Department of Chemistry and Biochemistry, University of Maryland, Bldg 091, University of Maryland, College Park, MD 20742. |
| Recent studies have shown that interfacial solvation depends sensitively on solvent structure, even though different solvents may behave quite similarly in bulk solution. Using surface specific vibrational spectroscopy we have begun studying a series of air/alkane interfaces. Not surprisingly, interfacial order and solvent orientation appear strongly correlated with molecular structure. For example, linear alkanes (n-decane up to n-hexadecane) all adopt a geometries with their long axes aligned along the surface normal, although the longer alkanes show greater conformational disorder within the interfacial region. These findings agree qualitatively with recent x-ray scattering studies. In contrast, branched isomers (e.g. heptamethylnonane (C16H34)) direct their long axes perpendicular to the surface normal as if to maximize interfacial methyl coverage. Additional studies have been carried out with cyclic and halogenated alkanes. These results will be discussed in the context of their impact on interfacial roughness and solvent polarity. |
|
Vibrational Analyses of Dry and Wet Surfaces
2:00 PM-5:30 PM, Wednesday, March 31, 2004 Marriott -- Grand Ballroom H, Oral
Division of Colloid and Surface Chemistry |