VIDEO MICROSCOPY OF MONODISPERSE COLLOIDAL SYSTEMS

Colloidal suspensions of uniformly sized microspheres can serve as powerful model systems for investigating many-body processes in condensed-matter physics. The ensemble of microspheres in such suspensions undergoes disorder-order transitions from fluids to crystals in direct analogy with the structural transitions experienced by atoms in conventional materials. Unlike atoms, however, colloidal spheres can be imaged and tracked using optical microscopy and computerized image processing. This reviewaddresses issues in the physics of phase transitions that have been attacked through digital video microscopy of colloidal dispersions over the past decade. Particular emphasis is placed on microscopic mechanisms of melting and freezing and on the effects of geometric confinement on these fundamental processes.