Density functional theory for colloidal rod-sphere mixtures

We present a density functional theory for a model colloidal mixture of hard spheres and infinitely thin hard rods. For these freely rotating particles, we use a fundamental measures approach to obtain a functional that features the correct dimensional crossover and the exact low density limit. For isotropic bulk fluid mixtures, the free energy, and hence the demixing phase diagram, are identical to that obtained from free volume theory. Results for the partial pair correlation functions of the bulk mixture are in good agreement with those of our simulations.