Berlin 2018 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 68: Poster: Complex Fluids, Glasses, Granular

DY 68.16: Poster

Donnerstag, 15. März 2018, 15:30–18:00, Poster A

A transient amorphous solid formed from low density aqueous charged sphere suspensions — •Ran Niu¹, Sabrina Heidt^1,2, Ramsia Sreji³, Riande Dekker⁴, Maximilian Hofmann¹, and Thomas Palberg¹ — ¹Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany — ²Graduate School Materials Science in Mainz, Staudinger Weg 9, D-55128 Mainz, Germany — ³Department of Chemistry Physical and Biophysical Chemistry (PC III), Bielefeld University, D-33615 Bielefeld, Germany — ⁴Debye Institute for Nanomaterials Science, Utrecht University, NL-3584 CC Utrecht, The Netherlands

We report the formation of a transient amorphous solid formed from charged polymer spheres suspended in thoroughly deionized water at volume fractions of 0.0002-0.01 [1]. From optical experiments, we observe the presence of short-range order and an enhanced shear rigidity as compared to the stable polycrystalline solid of body centred cubic structure. On a density dependent time scale of hours to days, the amorphous solid transforms into this stable structure. We further present preliminary dynamic light scattering data showing the evolution of a second slow relaxation process possibly pointing to a dynamic heterogeneity known from other colloidal glasses and gels. We compare our findings to the predicted phase behaviour of charged sphere suspensions and discuss possible mechanisms for the formation of this peculiar type of colloidal glass [2]. References 1.*T. Palberg, et al. J. Stat Phys. 2016, 074007 (2016). 2.*R. Niu, et al. Sci. Rep. accepted.