PHASE BEHAVIOR OF SIMPLE FLUIDS CONFINED IN COORDINATION NANOSPACE

摘要

Freezing behavior of Lennard-Jones (LJ) fluid confined in a coordination nanospace, or the metal-organic framework, was examined employing GCMC technique. A unit cell that contains at least 3x3 array of square channels divided by thin walls of single atom thickness was developed. The simulations clarified that the LJ-methane in graphene walls with the effective channel size of ca. 4σ exhibited extremely elevated freezing points. The significant elevation was considered to be brought not only by superimposed potential from walls, but also partly by the interaction between fluid molecules existing in different compartments through the ultrathin walls. Besides these factors, results of simulations with walls made up with fluid molecules themselves indicated possibility of additional enhancing factor for freezing that was not prevailing in slit-pore case.