Abstract

We use quasi-elastic light scattering to study the structure and dynamics of concentrated hard sphere colloidal suspensions in microgravity. The hard sphere system is the simplest and the most fundamental model system in condensed matter physics. At low volume fractions, ϕ < 0.494, the system is in a disordered state. At ϕ greater than 0.494, the system becomes ordered. Ground based studies of the crystalline phase are subject to sedimentation due to gravity. This paper reports the first experiment of a series planned for microgravity, the NASA Colloidal Order-Disorder Transition (CDOT) project conducted in the glovebox of the Second United States Microgravity Laboratory (USML2) which flew on board space shuttle Columbia from October 20 to November 5 in 1995. A detailed hardware description will be given by another paper. This paper is concerned with the scientific aspects of the experiments.

© 1996 Optical Society of America