Entropic patchiness: Effects of colloid shape and depletion

Abstract

This paper reviews ‘entropic patchiness’ of colloidal particles. On the one hand this may be due to their intrinsic tendency to form certain shape-dependent configurations in crowded suspensions, on the other hand this can be strongly enhanced by using depletion interactions that are also of purely entropic origin. A brief account of the Onsager theory and its consequences for the formation of colloidal liquid crystals of highly anisometric particles is presented. It is further supplemented by a recap of the description of depletion attraction between colloids and the effects of their shape. A number of recent examples exploiting entropic patchiness are discussed.