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

P5.36Wed 711:10-14:00Colloidal interactions via a polymer carpetTine Curk, 1 Francisco Martinez, 1 and Jure Dobnikar 11 University of Cambridge, Department of Chemistry, Lensfield Road, CB2 1EW,Cambridge, United KingdomWe present simulations of spherical colloids subject to gravity on a soft substrate. Substrate consistsof many polymer(DNA) chains grafted on a hard surface. At high grafting densities polymersform a brush and in this regime potential of mean force on colloids approaches harmonic potentialin vertical direction. However for lower grafting densities colloids fall through to the hard surface,chains form a mushroom like shapes and can effectively help to confine colloids to the surface.Colloids do not interact directly (except for hard core repulsion), interaction comes via substrateby entropic and depletion effects. Many body effects become very important and in turn this givesrise to interesting phase behavior.36