3D assembly of Janus spheres: potentials, dynamics, and experiments

Abstract

ABSTRACT Asymmetric colloidal Janus particles (JPs) have stimulated research which spans many disciplines, often due to possibilities for their assembly into larger structures. This review aims to identify opportunities for physicists and others working on spherical JPs clustering in bulk fluid, which is a simple and fundamental type of JP assembly. The review focuses on JPs with two hemispheres with differing surface properties but also considers ‘patchy’ particles with smaller or more numerous distinct surface areas. Research to date has featured many simulation methods, including point potentials with angular dependence, multi-site approaches, and detailed numerical techniques. The field lacks experiments and 3D simulations which allow clear quantitative comparisons and hence validation of fundamental principles, including the behaviour of so-called ‘floppy’ bonds between two or more JPs. Research into non-equilibrium clustering and the role of hydrodynamics in assembly will also be of ongoing interest, because these topics will be significant in any practical assembly strategy.