2017 Volume 17 Issue 2 Pages 63-75
Abiotic colloids in nonequilibrium states exhibit various types of motion. Unlike thermal motions, these motions can be transformed into regular motions in space and time. They can exhibit self-organized patterns, active transport, stimuli-responsive behaviors, and/or chemotaxes. Although these characteristics resemble biological motions, abiotic systems are composed of much simpler chemicals. Because motions are generated near the interface where colloids exchange matter with their surroundings, the moving system must be on the colloidal scale. In this review, catalytic particles in solution, dispersions of oil/water system, the oil/water interface itself, and amphiphilic molecular assemblies are introduced with an emphasis on our studies. We discuss the emergence of regular motions from apparently random fluctuations, self-organized patterns from numerous elementary particles, separation of matter using active motions of abiotic colloids, motion control by coexisting cation species, and chemotactic dynamics shown by amphiphilic molecular assemblies.
