SIMULATION STUDY OF THE STRUCTURE OF HALOMETHANES ON GRAPHITE AND SILICA SUBSTRATES

The present work provides a comparative molecular dynamics simulation study of the structure, packing and orientation of halomethane adsorbed on two homogeneous but chemically and structurally different substrates: graphite and α-quartz. The basic adsorbates are polar CF4 and non-polar CF3Cl and CF3Br molecules.The study shows that the geometry and electro-affinity of the surface atoms has an effect on the structure and layering of the film. Variation of temperature plays a role in the behavior of adsorbate molecules. Also we find a difference in packing of the molecules near the substrates as a function of film thickness. The dipole moment and order of the molecules are influenced by the surface effects. The packing of molecules is also commensurate with the polarity and size of the adsorbate molecule