New insights into colloidal phase transitions using neutron scattering techniques
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Date
2020-11-11
Authors
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Journal ISSN
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Publisher
Australian Institute of Nuclear Science and Engineering (AINSE)
Abstract
The fundamentals of crystallisation and glass formation in atomic systems are not yet fully understood. Hardsphere colloidal nanoparticles have been shown to be promising model systems for understanding crystallisation and glass formation in atomic systems: As colloidal motion is Brownian, rather than ballistic, kinetics and dynamics are orders of magnitude slower than in atomic systems and can be studied in real-time. However, despite previous work, key elements are still missing from our understanding of phase transition in colloidal suspensions especially regarding metastability, supercooling and the glass transition. In particular, there is still no clear understanding of the effects of polydispersity: although studies of both polydisperse and binary mixtures of hard sphere colloids have been performed, a systematic study of the effects of polydispersity on structure, crystallisation kinetics and particle dynamics is still lacking.
One of the reasons for this is the relatively limited types of suspensions which have be studied - most particles
used for such studies need to be suspended in mixed solvents for refractive index matching for light scattering studies, which introduces potential problems such as selective solvation and evaporation. In this work we
explore the possibility of using ionic liquids (ILs) and deep eutectic solvents (DESs) as the suspending solvent,
as these can be tuned to match the refractive index of the particles, and don’t suffer from evaporation. We will
then develop suitable binary colloidal suspensions consisting of deuterated & non-deuterated nanoparticles
suspended in the solvent. With a combination of lab techniques and beam time allocations at the Australian
Synchrotron, ANSTO and overseas neutron facilities, we will expansively investigate the nature of metastability, crystallisation and the glass transition, and provide a significant advance on our current understanding
of these processes.
Description
Keywords
Crystallization, Glass, Nanoparticles, Kinetics, Scattering, Eutectics, ANSTO, Neutrons
Citation
Chea, K., Bryant, G., Garvey, C., & Van Megan, B. (2020). New insights into colloidal phase transitions using neutron scattering techniques. Poster presented to the ANBUG-AINSE Neutron Scattering Symposium, AANSS 2020, Virtual Meeting, 11th - 13th November 2020. (pp. 68). Retrieved from: https://events01.synchrotron.org.au/event/125/attachments/725/1149/AANSS_Abstract_Booklet_Complete_-_1_Page_Reduced.pdf