(397c) Transport Behaviors of Shape-Changing Colloidal Particles

Polymer elastomers with reversible shape-changing capability have led to significant development of artificial muscles, functional devices, and soft robots. By contrast, reversible shape transformation of inorganic particles is notoriously challenging due to their relatively rigid lattice structure. Here, we demonstrate the synthesis of shape-changing nanoparticles via an asymmetrical surface functionalization process. This shape-changing particle provides an ideal “hard-rod” system that allows real-time adjustment of the aspect ratio of the colloidal particles in dispersions. Additionally, by modifying the particle shape and shape polydispersity, we showcase the role of particle morphology and morphology distribution on fluid behaviors under external shear forces. In particular, the dynamic rheology was monitored during the shape-changing process, and the effect of shape and shape polydispersity in dense particle fluids was quantified. These results not only help provide fundamental knowledge of fluid mechanics and particle transport, but also could potentially transform the frontiers of designing next-generation colloidal materials in commercial applications, including food, medicine, and manufacturing.