Nov 13, 2017
Professor Thomas Mason
Professor Thomas Mason and his research group have just published a joint paper on the glass and jamming transitions of concentrated nanoemulsions with their Swiss collaborators in Scientific Reports.
 
Professor Mason and his graduate students Ha Seong Kim and Matthew Pagenkopp worked with Professor Frank Scheffold and his postdoctoral researchers Marco Braibanti and Nesrin Şenbil from the Department of Physics at the University of Fribourg on “The liquid-glass-jamming transition in disordered ionic nanoemulsions”, published on Nov. 8, 2017.
 
This team investigated nanodroplet dynamics in concentrated silicone oil-in-water nanoemulsions using light scattering. Their experiments revealed a distinction between the glass transition, which is related to the onset of nonergodicity and loss of low-frequency relaxations, which occurs at slightly lower droplet concentrations than the jamming transition, which is related to the onset of deformation of the droplets. Graduate student Matthew Pagenkopp made and size-fractionated the nanoemulsions, and graduate student Ha Seong Kim performed modeling of the light scattering results. Their colleagues in Switzerland collaborated on the design of the experiments and performed the light scattering measurements.
 
Professor Mason commented, “By combining highly uniform nanoemulsions with advanced light scattering methods, we have been able to separate the hallmarks of the colloidal glass transition, associated with the dynamic arrest and caging of Brownian nanodroplets, from the repulsive jamming transition at a slightly higher droplet volume fraction, beyond which the nanodroplets effectively begin to touch and deform.”
 
Written by Laura Strom, UCLA Department of Chemistry and Biochemistry.