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

P5.176Wed 711:10-14:00Structure and phase behavior of highlysize-asymmetrical binary fluid mixturesNigel Wilding 1 and Douglas Ashton 11 University of Bath, Claverton Down, BA2 7AY, Bath, United KingdomHighly size-asymmetrical fluid mixtures arise in a variety of physical contexts, notably insuspensions of colloidal particles to which much smaller particles have been added in the formof polymers or nanoparticles. Conventional schemes for simulating models of such systems arehamstrung by the difficulty of relaxing the large species in the presence of the small one. Wedescribe Monte Carlo algorithms capable of tackling this problem and apply them to the problemof determining effective potentials in size asymmetrical hard sphere mixtures, thereby allowingquantitative tests of the predictions of density functional theory. We then introduce recentlydeveloped techniques that permit the accurate study of phase behavior and critical phenomena insize asymmetrical mixtures. The methods are applied to study the liquid-vapor phase diagramof a particular mixture of Lennard-Jones particles having a 10:1 size ratio. The results revealqualitatively different behavior to that expected from the standard depletion picture.[1] D. J. Ashton, J. Liu, E. Luijten and N. B. Wilding, J. Chem. Phys. 133, 194102 (2010).[2] D. J. Ashton and N. B. Wilding, Mol. Phys. published online: DOI:10. 1080/00268976(2010).176