6533b855fe1ef96bd12afdad

RESEARCH PRODUCT

Solidification of a colloidal hard sphere like model system approaching and crossing the glass transition

Hans Joachim SchöpeMarkus FrankeSebastian Golde

subject

Materials scienceNumber densityNucleationGeneral ChemistryHard spheresCondensed Matter Physicslaw.inventionCondensed Matter::Soft Condensed MatterCrystallographyDynamic light scatteringChemical physicslawMetastabilityStatic light scatteringCrystallizationGlass transition

description

We investigated the process of vitrification and crystallization in a model system of colloidal hard spheres. The kinetics of the solidification process was measured using time resolved static light scattering, while the time evolution of the dynamic properties was determined using time resolved dynamic light scattering. By performing further analysis we confirm that solidification of hard sphere colloids is mediated by precursors. Analyzing the dynamic properties we can show that the long time dynamics and thus the shear rigidity of the metastable melt is highly correlated with the number density of solid clusters (precursors) nucleated. In crystallization these objects convert into highly ordered crystals whereas in the case of vitrification this conversion is blocked and the system is (temporarily) locked in the metastable precursor state. From the early stages of solidification one cannot clearly conclude whether the melt will crystallize or vitrify. Furthermore our data suggests that colloidal hard sphere glasses can crystallize via homogeneous nucleation.

https://doi.org/10.1039/c4sm00653d