The flow of molecular monolayers in relation to the design of Langmuir troughs and the deposition of Langmuir-Blodgett films

Abstract

The flow of condensed molecular monolayers of barium stearate has been examined as a model system in relation to the deformation of monolayers during experimental procedures. It is shown that when a monolayer is transferred at constant area along the surface in a Langmuir trough the movement of the monolayer in relation to the boundaries sets up a circulation in the surface. This can be eliminated by a simple modification to a conventional trough. A new method is described to follow the progressive distortion of the monolayer during deposition of Langmuir-Blodgett films. This is applied to show how distortion can be minimised in a conventional Langmuir trough and to produce designs using a flexible belt to compress the monolayer. A belt profile is proposed which can be used to deposit the monolayer with minimal distortion.