When nano-ions meet polar and electrically neutral matter
Quand ? |
Le 28/06/2022, de 11:00 à 12:00 |
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Où ? | Salle des thèses |
Participants |
Olivier Diat |
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Beyond electrostatic, the interaction of ions with their close environment depends also on their hydration shell and the water dynamic in this environment. Non-negligible water-mediated effects can indeed influence many physical chemistry processes such as cloud point, protein salting-in or out, bubble coalescence, the topology of bilayers... This type of interaction is qualified of "ion specific". During the last 10 years, our team has shown that these effects can be exalted with nanometer-sized ions. These latter can indeed bind to polar and electrically neutral matter in solution although these ions are highly charged but always characterized by low charge density. This nano-ion specific effect, called superchaotropic in referring to the extension of the “Hofmeister series”, arises from the partial dehydration of both the nano-ions and the solutes or surfaces in interaction, with a significant gain in enthalpy for the combined system. Moreover, some of these nano-ions have electronic properties that can be exploited for various applications covering catalysis, biology, metal recycling, and so on. The characterization of this effect is strongly supported by scattering experiments, neutron, and x-ray (to build phase diagrams and describe new assemblies). Spectral techniques such as NMR, UV-vis, fluorescence, and so on, allow targeting the predominant chemical functions in interaction with the nano-ions that can vary depending on their supramolecular environments. In this presentation, we will describe selected examples showing all the interest to develop such physical chemistry around nano-ions.