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

Wed 711:10-14:00P5.61The Kern-Frenkel model for patchy colloids by means ofthe thermodynamics perturbation theoryChristoph Gögelein, 1 Riccardo Fantoni, 2 Flavio Romano, 3 Francesco Sciortino, 4and Achille Giacometti 51 Max-Planck-Institute for Dynamics and Self-Organization, Dept. Dynamics of complexFluids, Am Fassberg 17, 37077, Göttingen, Germany2 Department of Physics, University of Stellenbosch, Stellenbosch, South Africa3 Physical and Theoretical Chemistry Laboratory, Oxford University, Oxford, UnitedKingdom4 Università di Roma ”La Sapienza”, Roma, Italy5 Dipartimento di Scienze Molecolari e Nanosistemi, Universita’ Ca’ Foscari Venezia,Venezia, ItalyWe study the Kern-Frenkel model for patchy colloids by means of second-order thermodynamicsperturbation theory (TPT) This model describes a fluid where hard spheres particles are decoratedwith one or two attractive patches, so that they interact via a square-well potential provided thatthey are sufficiently close one-another, and that the patches on each particles are properly aligned.Both the fluid-fluid and the fluid-solid coexistence phases are computed and contrasted againstspecialized Monte-Carlo simulations. In spite of the known shortcomings, we find that perturbationtheory can describe coexistence phases all the way from a fully covered square-well potential downto its hard sphere counterpart. In the region where numerical data are available (from squarewellto Janus), the agreement between theory and simulations is impressive. Comparison with avirial expansion further strenghtens the fact that TPT provides a very convenient tool for a firstapproximate location of critical points and coexistence lines, and hence an useful guideline to anefficient numerical simulations.[1] A. Giacometti, F. Lado, J. Largo, G. Pastore, and F. Sciortino, J. Chem. Phys. 131, 174114(2009)[2] F. Sciortino, A. Giacometti, and G. Pastore, Phys. Rev. Lett. 103, 237801 (2009)[3] A. Giacometti, F. Lado, J. Largo, G. Pastore, and F. Sciortino, J. Chem. Phys. 132, 174110(2010)[4]F. Sciortino, A. Giacometti, and G. Pastore, Phys. Chem. Chem. Phys. 12, 11869 (2010)[5] R. Fantoni, A. Giacometti, F. Sciortino and G. Pastore, Soft Matter 7, 2419 (2011)[6] C. Gögelein, G. Nägele, R. Tuinier, T. Gibaud, A. Stradner, P. Schurtenberger, J. Chem. Phys.129, 085102 (2008)[7] R. Fantoni, D. Gazzillo, A. Giacometti, M. A. Miller and G. Pastore, J. Chem. Phys. 127,234507 (2007)61