Year: 2010
Journal: Applied Surface Science, Volume 256, Issue 7, 15 January 2010, Pages 1969-1971, 20111221
Authors: Sadaharu Jo, Kentaro Okamoto and Mitsuru Takenaga
Organizations: Division of General Education, Aichi-Gakuin University, 12 Araike, Iwasaki-cho, Nisshin 470-0195, Japan, Department of Applied Chemistry, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyoonoda, Yamaguchi 756-0884, Japan
The effect of backbone chains on friction force was investigated on both Langmuir–Blodgett (LB) films of 10,12-heptacosadiynoic acid and the (0 1 0) surfaces of single crystals of 2,4-hexadiene-1,6-diol using friction force microscopy (FFM). It was observed that friction force decreased when the scanning direction was parallel to the [0 0 1] direction in both samples. Moreover, friction force decreased when the scanning direction was parallel to the crystallographic [1 0 2], [1 0 1], [1 0 0] and 
directions in only the single crystals. For the LB films, the [0 0 1] direction corresponds to the backbone chain direction of 10,12-heptacosadiynoic acid. For the single crystals, both the [0 0 1] and [1 0 1] directions correspond to the backbone chain direction, and the [1 0 2], [1 0 0] and 
directions correspond to the low-index crystallographic direction. In both the LB films and single crystals, the friction force was minimized when the directions of scanning and the backbone chain were parallel.
