Advanced Colloids Experiment – Temperature-4 (ACE-T-4)

Introducing disorder to a crystalline system in a controlled way can form glass. Advanced Colloids Experiment-Temperature-4 (ACE-T-4) examines the transition of an ordered crystal to a disordered glass to determine how increasing disorder affects structural and dynamic properties. The investigation controls disorder by controlling temperature in a series of samples and observes the microscopic transition in three dimensions.

The experiment has concluded, and science is being evaluated.

The Advanced Colloids Experiment-Temperature-4 (ACE-T-4) experiments provide insight into how increasing disorder in an initially crystalline material can affect melting, freezing, aging and other structural and dynamic properties. The findings are important for applications (on Earth) wherein materials must be maintained as either glassy or crystalline for long periods of time, or for materials applications where it is desirable to convert the state of material between crystalline and glass-like.

The nature of solidification and dynamic arrest of microscopically disordered materials is an important topic of study in materials science and condensed matter physics. The conventional model of the fluid-to-solid transition is marked by a discontinuous increase in structural order at the atomic scale. In the solid phase, such systems exhibit obvious crystalline order. However, there also exists a class of materials where the system forms a phase with solid-like macroscopic properties but no apparent atomic structural order. These disordered solid packings are referred to as “disordered solids” or “glasses.” Gaining new understanding about how these disordered materials solidify is an important goal in condensed matter physics and materials science that could lead to the engineering of new materials with tunable strength, fragility, and malleability.

Previous studies with colloidal systems found that gravity dramatically affects the structure and dynamics of a newly formed crystal. In terrestrial experiments, Earth’s gravity masks these effects. Performing experiments in microgravity thus allows better understanding of the fundamental physics of nucleation, aging, melting, and glass formation in increasingly disordered materials. These experiments help develop and test new technology for observation and synthesis of new colloidal materials and colloid engineering in microgravity.

These experiments contribute to understanding of the transition from ordered (crystal) to disordered (glassy) materials and provides fundamental insight into glass formation in materials with varying degrees of order. The findings have important applications on Earth where materials must be maintained as either glassy or crystalline for long durations and for materials applications that require conversion of materials between crystalline and glassy.

Space Station Research Explorer