8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Thu 811:10-14:00P7.15Freezing of simple fluids in regular and disorderedcarbon nanotubesBenoit Coasne, 1 Keith Gubbins, 2 and Malgorzata Sliwinska-Bartkowiak 31 CNRS - Institut Charles Gerhardt Montpellier, 8 rue de l Ecole Normale, 34096,Montpellier, France2 Centre for High Performance Simulation and Department of Biomolecular and ChemicalEngineering, Raleigh, United States of America3 Faculty of Physics, Poznan, PolandFreezing of liquids confined at the nanoscale is relevant to practical applications involving lubrication,adhesion, and nanotribology. From a fundamental point of view, freezing of liquids confinedin nanopores can be used to estimate the effect of confinement and surface forces on the thermodynamicsand dynamics of fluids. Nanoporous carbons, such as carbon nanotubes and carbon replicasobtained from a porous material using a template mechanism, are porous solids that attract a greatdeal of attention because of their possible use in industry as adsorbents, etc. From a fundamentalpoint of view, these porous carbons can be used to investigate the effect of confinement, reduceddimension, and surface forces on the thermodynamic properties of fluids. In this paper, we report aMonte Carlo molecular simulation study on the freezing of argon in regular and disordered carbonnanotubes. The regular porous carbon (Model A) is simply a carbon nanotube of a regular size.The disordered carbon nanotube (Model B) is a structural model of carbon replica obtained froma template mechanism using porous silica SBA-15. The morphological and topological featuresof model B represents in a realistic way the disordered structure of CMK materials. This studyis aimed at estimating how the effect of disorder of the porous material affects freezing of simpleadsorbates. The structure of the confined fluid is analyzed using order parameters and positional orbond orientational pair correlation functions. We also analyze our data using a method we recentlyproposed (Coasne et al. Phys. Rev. Lett. 2006) for analyzing freezing in disordered materials.In this approach, freezing is monitored by looking at local bond-order parameters and averagenumber of crystalline-like atoms.15