Unique assembly structures of amphiphilic Janus particles in ionic liquid solutions

Janus particles assemble into remarkable superstructures due to different chemistry on the two sides of a single particle. The directional interactions present new structures and the ensuing physics are essential to the formation of intriguing clusters, chains and crystals. Our recent experiments demonstrate unique assemblies of Janus particles in ionic liquid solutions that have never been observed before. Despite extensive studies focused on purified Janus particles, their self-organization in the presence of surface-active molecules has not been systematically studied. The intriguing orientation correlation and crystal structures formed in this multicomponent system cannot be explained by the current theory. Our central hypothesis is that the association of surface active molecules with Janus spheres, especially the boundary on the particle surface dividing the two sides, can effectively modulate the interactions among Janus particles and alter their assembly behaviors. The results provide critical information regarding new phenomena observed through experimentation and offer guidance for future applications of Janus particles.