S. Marín-Aguilar, Wensink, H. H., Foffi, G., and Smallenburg, F., “Slowing down supercooled liquids by manipulating their local structure”, Soft Matter, vol. 15, p. 9886-9893, 2019. WebsiteAbstract
Glasses remain an elusive and poorly understood state of matter. It is not clear how we can control the macroscopic dynamics of glassy systems by tuning the properties of their microscopic building blocks. In this paper{,} we propose a simple directional colloidal model that reinforces the optimal icosahedral local structure of binary hard-sphere glasses. We show that this specific symmetry results in a dramatic slowing down of the dynamics. Our results open the door to controlling the dynamics of dense glassy systems by selectively promoting specific local structural environments.
P. Vodnala, et al., “Hard-sphere-like dynamics in highly concentrated alpha-crystallin suspensions”, PHYSICAL REVIEW E, vol. 97, p. 020601, 2018.Abstract
The dynamics of concentrated suspensions of the eye-lens protein alpha crystallin have been measured using x-ray photon correlation spectroscopy. Measurements were made at wave vectors corresponding to the first peak in the hard-sphere structure factor and volume fractions close to the critical volume fraction for the glass transition. Langevin dynamics simulations were also performed in parallel to the experiments. The intermediate scattering function f (q, tau) could be fit using a stretched exponential decay for both experiments and numerical simulations. The measured relaxation times show good agreement with simulations for polydisperse hard-sphere colloids.