Relation between film structure and microtribological properties of mixed LB films

COLL 319

Shigeyuki Mori, Hidetaka Nanao, Tomohiro Higuchi, Tomoo Kubo, and Ichiro Minami. Department of Applied Chemistry, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan
Mixed LB films were used as a model of boundary films for microtribological friction tests under low loads. Several types of fatty acids and esters were used as the component. Hydrocarbon and partially fluorinated alkyl chains were selected for the component. Molecular orientation and two-dimensional distribution of the component in the films were investigated with a high-sensitive UV spectroscopy and Time of Flight Secondary Ion Mass Spectroscopy, respectively. It was found that friction properties of the films were closely dependent on the film structure, that is, molecular orientation of the component in a film and two-dimensional mixing. When hydrocarbon and fluorocarbon chains were mixed, a stick-slip phenomenon was observed. The result was explained by a mobility of the component.