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.
32 pages, 7 figures, accepted for publication in the journal Scientific Reports
References in corpus (4)
- 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
- Broadband dielectric spectroscopy on benzophenone: alpha relaxation, beta relaxation, and mode coupling theory