Fun and Profit with Janus Colloids

The colloidal state is the stage on which many of the great themes of Matt Tirrell’s career find their natural meeting place.   In this talk, I will consider Janus colloids, which violate the textbook notion that particle-particle interactions are isotropic and depend solely on separation.  Instead, in the laboratory it is now straightforward to create diblocks, which are the colloidal analogue of molecular surfactants, and triblocks, which are the colloidal analogue of ABA and ABC triblock copolymers.  Amazing and potentially useful superstructures result from their directed self-assembly.  Powerful design rules to produce targeted supracolloidal structures will be described.  Unsolved problems for the future will be emphasized.