Y. Nakagawa et al., MOLECULAR-SCALE STRUCTURES OF LANGMUIR-BLODGETT-FILMS OF FATTY-ACIDS OBSERVED BY ATOMIC-FORCE MICROSCOPY, JPN J A P 1, 34(7B), 1995, pp. 3898-3902
Langmuir-Blodgett films of arachidic acid, barium arachidate, and a mi
xture of arachidic and behenic acids on a chemically flattened silicon
substrate were observed by atomic force microscopy. The films were fo
und to contact tightly with the substrate with a molecular slip at its
steps. Lattice expansion due to barium ions was found on the barium a
rachidate film but not on the pure acid film. In addition, the 2 x 2 s
uperlattice was found on the barium arachidate film. The superlattice
structure may be caused by the formation of a hydrogen salt. Although
no phase separation was found on the film made of a 9:1 mixture of the
acids, the image of the expected molecular mixture has not been obtai
ned so far.