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

P5.54Wed 711:10-14:00Cluster theory of Janus particlesRiccardo Fantoni, 1 Achille Giacometti, 2 Francesco Sciortino, 3 and GiorgioPastore 41 National Institute for Theoretical Physics (NITheP), Private Bag X1, 7600, Stellenbosch,South Africa2 Dipartimento di Scienze Molecolari e Nanosistemi, Venezia, Italy3 Dipartimento di Fisica, Universita’ di Roma La Sapienza, Roma, Italy4 Dipartimento di Fisica dell’ Universita’ di Trieste, Trieste, ItalyWe apply a simple statistical mechanics cluster approximation for studying clustering in the Kernand Frenkel model of Janus fluids. The approach is motivated by recent Monte Carlo simulationswork on the same model revealing that the vapor coexisting with the liquid phase contains clustersof different sizes and shapes whose equilibrium concentrations in general depend on the interactionrange as well as on thermodynamic parameters. The approximation hinges on a separation betweenthe intra- and intercluster contribution to thermodynamics, where only the former is explicitlycomputed by Monte Carlo simulations. Two level of a simple liquid theory approximations areexploited for the description of the latter. In the first we use the ideal-gas expressions and obtaina qualitative agreement with extensive Monte Carlo bulk simulations. This can be improved to asemi-quantitative agreement, by using a hard-sphere description for the cluster-cluster correlations.54