MOLECULAR-DYNAMICS OF A SOLID HYDROCARBON MONOLAYER

A solid hydrocarbon monolayer comprising n-octane chains interacting w ith an elastic substrate was modeled by methods of molecular dynamics. The calculation scheme allows for all details of the chemical structu re of molecules. It is established that the substrate produces weak pe rturbations in the adjacent regions of the monolayer: structural defec ts appear only in the boundary regions of this layer. The outer surfac e of the monolayer exhibits an insignificant ''roughness.'' The room-t emperature amplitude of the fluctuational displacements of atoms from average positions is about 0.15 nm. It is demonstrated that mobility o f various parts of the chains strongly depends on their orientation wi th respect to the surface of monolayer and on the distance from substr ate.