Effect of adding nanometre-sized heterogeneities on the structural dynamics and the excess wing of a molecular glass former
arXiv:1609.06822 · doi:10.1038/srep35034
Abstract
We present the relaxation dynamics of glass-forming glycerol mixed with 1.1 nm sized polyhedral oligomeric silsesquioxane (POSS) molecules using dielectric spectroscopy (DS) and two different neutron scattering (NS) techniques. Both, the reorientational dynamics as measured by DS and the density fluctuations detected by NS reveal a broadening of the alpha relaxation when POSS molecules are added. Moreover, we find a significant slowing down of the alpha-relaxation time. These effects are in accord with the heterogeneity scenario considered for the dynamics of glasses and supercooled liquids. The addition of POSS also affects the excess wing in glycerol arising from a secondary relaxation process, which seems to exhibit a dramatic increase in relative strength compared to the alpha-relaxation.
arXiv comment32 pages, 7 figures, accepted for publication in the journal Scientific Reports
References in corpus (10)
- The Excess Wing in the Dielectric Loss of Glass-Formers: A Johari-Goldstein beta-Relaxation?
- Broadband Dielectric Spectroscopy on Glass-Forming Propylene Carbonate
- Excess wing in glass-forming glycerol and LiCl-glycerol mixtures detected by neutron scattering
- Nearly-logarithmic decay of correlations in glass-forming liquids
- High-frequency dynamics of type-B glass formers investigated by broadband dielectric spectroscopy
- Picosecond Dynamic Heterogeneity, Hopping and Johari-Goldstein Relaxation in Glassforming Liquids
- Broadband dielectric spectroscopy on benzophenone: alpha relaxation, beta relaxation, and mode coupling theory
- Validity of Stokes-Einstein Relation in Soft Colloids up to the Glass Transition
- Scaling of broadband dielectric data of glass-forming liquids and plastic crystals
- Ions in glass forming glycerol: Close correlation of alpha and fast beta relaxation