A MOLECULAR-DYNAMICS SIMULATION OF PRESSURE-INDUCED LIQUID-PLASTIC PHASE-TRANSITION OF PURE CYCLOHEXANE AND CYCLOHEXANE IN SILICA CAVITIES

Molecular dynamics simulations at temperature 313 K and pressures up to 4 kbar for six-centre Lennard-Jones model of C6H12 are reported. The calculations are performed for pure cyclohexane and cyclohexane in pores. A cavity is obtained by placing silica clusters at the corners of a cubic box. Two cavities of diameter of about 30 Angstrom and 50 Angstrom are considered. Thermodynamic, structural and dynamic properties of molecule confined to the pores are compared with the results for pure cyclohexane. Changes of molecular behaviour with diminishing pore size are observed and the liquid-plastic transition point shifts to higher pressures.