2009/09/16 by R. Angelini, Roberta Angelini, G. Salvi +5
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Material Dynamics and Properties #Phase Equilibria and Thermodynamics #Soft Condensed Matter (cond-mat.soft) #cond-mat.dis-nn #cond-mat.soft
paper · pdf · doi:10.48550/arxiv.0909.3050
4 pages, 5 figure
arxiv created 2009/09/16 · openalex publication_date 2009/09/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We studied the rheological behavior of a molecular solution composed of α-cyclodextrin, water and 4-methylpyridine, a liquid known to undergo inverse melting, at different temperatures and concentrations. The system shows a marked non-Newtonian behavior, exhibiting the typical signature of shear thickening. Specifically, a transition is observed from a Newtonian to a shear thickening regime at a critical shear rate γc. The value of this critical shear rate as a function of T follows an Arrhenius behavior γc(T)= B exp(Ea/KBT), with an activation energy Ea close to the value of the hydrogen bond energy of the O-H group of the α-CD molecules. We argue that the increase of viscosity vs shear rate (shear thickening transition) is due to the formation of hydrogen bonded aggregates induced by the applied shear field. Finally, we speculate on the possible interplay between the non-Newtonian rheology and the inverse melting behavior, proposing a single mechanism to be at the origin of both phenomena.