화학공학소재연구정보센터
Thin Solid Films, Vol.242, No.1-2, 283-288, 1994
Head-to-Tail or Head-to-Head Structure of Langmuir-Blodgett Long-Chain Ester Multilayers
The effect of the deposition velocity on the type of transfer (X-, Y- or XY-) of methylarachidate and methylbehenate monolayers is investigated. To provide conditions for deposition of monolayers, but not of three-dimensional aggregates, the effect of the temperature on monolayer stability at constant surface pressure is followed at first. It is found that the gradual increase of the deposition velocity results in a transition from X- to Y-type transfer of the layers. Transition from X- to Y-type deposition is also observed on increase of the number of deposited monolayers. Small angle X-ray diffraction investigation reveals repeated spacings of a bilayer (head-to-head) structure for Y-type deposition. Structural similarity is found for multilayers built up by either XY- or X-type transfer. The specific electron density profile of the methyl ester films might result in a misleading conclusion about head-to-tail molecular arrangement in the multilayers.