COLL 316 |
| Miquel Salmeron, Materials Sciences Division, Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Mail Stop 66, Berkeley, CA 94720 |
| The packing, structure and mechanical stability of self-assembled monolayers of alkyl chain lubricants (thiols, silanes, amines and carboxylic acid) and polythiophene oligomers on mica, silicon oxide and gold were studied by AFM. Three types of interactions can be identified that control the packing and tribological properties of the films: van der Waals molecule-molecule, van der Waals molecule-substrate and short-range molecule-substrate interactions (covalent and ionic). The van der Waals interactions depend strongly on chain length, with the molecule-substrate interactions dominating for short chains and inter-molecular interactions dominating for long chains. The short range molecule-substrate forces are the strongest ones and are influenced by coadsorbed species, particularly environmental water. This in turn controls their tribological properties. |
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Friction, Lubrication, and Adhesion in Micro- and Nano-Scale Devices
8:30 AM-12:00 PM, Tuesday, March 30, 2004 Marriott -- Orange County 5, Oral
Division of Colloid and Surface Chemistry |