Solvation Effects on Self-association and Segregation Processes in tert-Butanol - Aprotic Solvent Binary Mixtures
Résumé
The present study reveals that the fully miscible binary mixtures consisting of tert-butanol with aprotic solvents form well-defined ordered supermolecular structures, which have been characterized on different lengthscales. Three different types of microstructures have been determined. They are separated by distinct crossovers that appear as a function of the dilution rate, going from "correlated clusters" to "diluted clusters" and "diluted monomers" microstructures. These observations have been made possible by the combination of Raman vibration spectroscopy, 1H NMR , and neutron diffraction that probe respectively the cluster formation (self-association) and the inter-cluster correlations (clusters segregation). The solvation effects on both the cluster formation and the inter-cluster correlations have been assessed by tuning the alcohol-solvent interaction i.e. changing the chemical nature of the diluting solvent from a purely inert alkane to a weakly interacting aromatic system.