Colloid-2) , Two Investigations Selectable Optical Diagnostics Instrument - Aggregation of Colloidal Solutions (SODI-Colloid/SODI-
(SODI-COLLOID/SODI-COLLOID-2) , TWO INVESTIGATIONS
Research Area: Complex Fluids
Expedition(s): 23-26, 29 and 30
Principle Investigator(s): ● Gerard Wegdam, University of Amsterdam, Netherlands
● Roberto Piazza, PhD, Politecnico di Milano, Italy
RESEARCH OBJECTIVES
The Selectable Optical Diagnostics Instrument - Aggregation of Colloidal Suspensions (SODI-
Colloid) investigation studies the growth, mixing, and ordering effects during microgravity
aggregation from solutions of colloids (ie, mixtures of particles made of materials and that have
the characteristic of remaining evenly distributed within a material medium without settling
out). The primary focus is on the use of binary fluid solvent mixture as a growth medium, which
may enable the development of fine-scale, tunable crystals resulting in an optically purer
product. By examining the three-dimensional ordering and crystallization of colloids, this study
intends to directly examine the mechanisms that could advance the development of photonic
materials, which are useful in developing devices that confine and direct the optical
propagation of electromagnetic waves and signals.
EARTH BENEFITS
SODI-Colloid results potentially could improve such colloids as paints, food products, drug
delivery systems and ceramics by providing a better understanding of the properties, and
designing of colloidal products.
SPACE BENEFITS
Colloidal engineering processes have the
potential to contribute to the creation of
new materials and products that may
enhance electronic communication
hardware within various space
architectures.RESULTS
The original concept of this experiment
was that the strength of interactions
between the colloidal particles could be
tuned by using a binary mixture as solvent
and increasing the temperature towards its
spinodal decomposition. The critical
Casimir effect resulting from the varying
length scale of the fluctuations in the solvent then increased the strength of attraction between
particles and could be easily and continuously tuned over a significant range without changing
the composition of the system. While the strength of the attractive force between particles was
Metal nanoparticles produced in microgravity. The SODI-
Colloid experiment is studying the growth and properties of
advanced photonic materials, core elements of the super-
fast optical computers to come. ESA image.