Binodal Colloidal Aggregation Test – 4: Polydispersion (BCAT-4-Poly).............................................
Research Area: Complex Fluids
Expedition(s): 16-20, 29-ongoing
Principal Investigator(s): ● Paul M. Chaikin, PhD, New York University, New York, New
York
RESEARCH OBJECTIVES
Binodal Colloidal Aggregation Test-4 (BCAT-4-Poly) is an experiment of 2 samples containing
microscopic spheres suspended in a liquid that are designed to determine how crystals can
form from the samples after they have been well mixed. The 2 samples have the same average
sphere size but 1 of them has a wider range (more polydisperse) of sizes in order to
demonstrate the dependence of crystallization on particle size range. Results from these
experiments help scientists develop
fundamental physics concepts that will
enable the development of a wide range
of next generation technologies (such as
in high-speed computers and advanced
optical devices).
EARTH BENEFITS
Generally, colloidal nucleation
experiments seek an understanding of the
most fundamental liquid/solid transition.
Though direct applications of that
understanding do not drive the research,
growth of ordered colloidal phases has
attracted interest in a number of areas like ceramics, composites, optical filters, and photonic
bandgap materials. Moreover, there is currently great interest in using fields and gradients to
control order in self-assembled systems such as diblock copolymers and microemulsions for
advanced materials.
SPACE BENEFITS
BCAT-4-Poly will ultimately impact our understanding of the strength and thermal conductivity
of materials by providing insight into the effects of size variation in dense suspensions of
particles. For example, the careful selection of crystallization promoters for controlling the
crystallite size and size distribution may lead to improvement in materials fabrication
processes. The suppression of crystal nucleation in polydisperse colloids has important
implications for the morphology of polycrystalline materials.
RESULTS
Data analysis is ongoing, and results are yet to be published.
This investigation is ongoing and additional results are pending publication.
BCAT-4 setup aboard International Space Station during
Expedition 20.