Université de Fribourg

Interplay of coarsening, aging, and stress hardening impacting the creep behavior of a colloidal gel

Calzolari, D. C. E. ; Bischofberger, Irmgard ; Nazzani, Francesco ; Trappe, Véronique

In: Journal of Rheology, 2017, vol. 61, no. 4, p. 817–831

We explore the dynamical and mechanical characteristics of an evolving gel in diffusing wave spectroscopy (DWS) and rheometry, aiming to assess how the gel evolution impacts the creep response of the system. Our gel is formed by inducing the aggregation of thermosensitive colloids by a variation in temperature. We find experimental evidence that the long time evolution of this gel is due to...

Université de Fribourg

Hydrophobic hydration of poly-N-isopropyl acrylamide: a matter of the mean energetic state of water

Bischofberger, Irmgard ; Calzolari, D. C. E. ; Rios, Paolo De Los ; Jelezarov, I. ; Trappe, Véronique

In: Scientific Reports, 2014, vol. 4, p. -

The enthalpically favoured hydration of hydrophobic entities, termed hydrophobic hydration, impacts the phase behaviour of numerous amphiphiles in water. Here, we show experimental evidence that hydrophobic hydration is strongly determined by the mean energetics of the aqueous medium. We investigate the aggregation and collapse of an amphiphilic polymer, poly-N-isopropyl acrylamide (PNiPAM), in...