title: Transition between collective behaviors of micromotors in response to different stimuli.
abstract: We report a Ag(3)PO(4) microparticle system showing collective behaviors in aqueous medium. Transition between two emergent patterns, namely "exclusion" and "schooling", can be triggered by shift in chemical equilibrium upon the addition or removal of NH(3) or in response to UV light. The transitions are consistent with a self-diffusiophoresis mechanism resulting from ion gradients. The reported system is among the few examples of nanomotors that are based on a reversible nonredox reaction and demonstrates new design principles for micro/nanomotors. Potential applications of the reported system in logic gates, microscale pumping, and hierarchical assembly have been demonstrated.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Wentao
authors.initials: W
authors.lastname: Duan
authors.forename: Ran
authors.initials: R
authors.lastname: Liu
authors.forename: Ayusman
authors.initials: A
authors.lastname: Sen
mesh_terms: D000641:Ammonia / Q000737:chemistry; D008958:Models, Molecular; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry*; D018030:Silver Compounds / Q000737:chemistry*; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D010710:Phosphates; D018030:Silver Compounds; D000641:Ammonia; C039072:silver phosphate