being increased, the growth rate of aggregates and the average feature of their structure were
quantified by way of Near Field Scattering measurements.
In microgravity, fractal structures formed by diffusion limited aggregation are always obtained,
even at the lowest strength of inter-particle attraction, with a fractal dimension that decreases
continuously with increasing attraction. This could not be ascribed to a change in a cluster-
cluster aggregation regime. Simultaneously, ground experiments with the same samples
showed only one type of aggregate with a constant fractal dimension, formed by a reaction-
limited process. The experiment demonstrated the possibility of investigating aggregation
mechanisms and the resulting structure of colloidal solids by tuning interaction forces in a
colloid suspension by changing the temperature of the mixture.
PUBLICATION(S)
Mazzoni S, Potenza M, Alaimo M, et al. SODI-COLLOID: A combination of static and dynamic
light scattering on board the International Space Station. Rev Sci Instr. 2013;84(4):043704. doi:
10.1063/1.4801852.
Veen SJ, Antoniuk O, Weber B, et al. Colloidal aggregation in microgravity by critical Casimir
forces. Physical Review Letters 109. 2012. doi:10.1103/PhysRevLett.109.248302.
This investigation is complete and all results are published.