COLL 42 |
| Mischa Bonn and Sylvie Roke. Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, Netherlands |
| Phospholipids are key constituents of cell membranes. Thanks to their amphiphilicity and ability to self-organize they form the skeleton of living cells. We have investigated the self-organizing behaviour of a phospholipid monolayer, in contact with water. We can map the order inside the alkyl chains using Vibrational Sum-Frequency Generation (VSFG), and the mesoscopic properties of the monolayer using fluorescence microscopy. This unique combination of optical tools allows us to observe, as the molecular surface area is increased, a novel, sharp phase transition, attributed to the curling up of the apolar alkyl chains as their exposure to the polar water environment increases, in addition to the known transitions. We also present recent results on the novel application of VSFG in a scattering geometry to the study of molecular behaviour on non-planar surfaces, allowing us to extract information about the molecular order and orientation at the surface of sub-micron sized particles. |
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Vibrational Analyses of Dry and Wet Surfaces
2:00 PM-5:45 PM, Sunday, March 28, 2004 Marriott -- Grand Ballroom H, Oral
Division of Colloid and Surface Chemistry |