Molecular dynamics simulation of Langmuir-Blodgett films

Abstract

Computer simulations can be used to study certain chemical and physical systems, such as molecular films on a solid or liquid surface. The present study concentrates on a class of molecular monolayers, Langmuir-Blodgett (LB) films. Although the phenomena and the structure at the molecular scale of these films have been studied widely by experimental methods, the experiments show only either the macroscopic properties or statistical averages of the phenomena at the nanometre scale. Thus the microscopic phenomena are not revealed. Computer simulations, thought as experiments at microscopic scale, can be used to correct this disadvantage. These small-scale experiments clarify the causes of visible phenoma, giving a view to the unvisible, to molecular or atomic scale. -The main purpose of this study is to model the first stage of the LB film preparation: the compression of a monolayer on a liquid surface from the phase of its free spreading to its closest packing, to Langmuir films.The method of molecular dynamics (MD) simulation is used in the study.The main purpose of this study is to investigate the surface tension, surface pressure and the structure of the monolayer during the compression process.

AB3:Työssä tarkastellaan Langmuir-Blodgett kalvojen valmistusta ja rakennetta,esitetään molekyylidynaaminen simulointimalli kalvojen valmistukselle jasovelletaan sitä eri tavalla keskenään vuorovaikuttavillemolekyylikalvoille.