Colloidal molecules and patchy particles: complementary concepts, synthesis and self-assembly.

This review describes the latest advances in the synthesis and assembly of specific colloids such as the colloidal molecules as defined by van Blaaderen in 2003 and the patchy particles imagined a few years later. The two concepts are closely related because some may serve as precursors of others and vice versa. To best mimic the molecular structures, it is necessary to introduce the notions of directed binding and valence which result in the concept of patches arranged on the particle surface according to the conventional repulsion figures. The assembly of patchy particles has made it possible to reconstitute molecules and macromolecules of simple geometry. But the existence of extended assemblies of larger dimensions has been demonstrated mostly by simulation and it struggles experimentally with the purity of the batches of building blocks.