ILLA

The ILLA project gathers three complementary teams to study in synergy liquid/liquid "LL" interfaces involved in the assisted ion extraction from water to an organic "oil" phase. This biphasic process is the basis of hydrometallurgical applications of outmost importance such as metal ion extraction or recycling. By coupling specific surface experiments and molecular simulations, we investigate the characteristics of relevant LL interfaces (size, polarity, dynamics, local intermiscibility of liquids), and the concentration and ordering of "adsorbed" species (extractants, complexes, …), following four well defined and parallel tasks. The aim is to obtain detailed molecular insights into interfacial events involved in the transfer of metallic cations (e.g. Ln3+ lanthanides) from an aqueous to an oil phase upon complexation with extractant molecules (e.g. lipophilic diamides). ILLA is a fundamental project combining for the first time synthesis of a "reporter" extractant, non linear optics spectroscopy (SHG) coupled with surface tension measurements, and simulations (molecular dynamics) on the same systems. Beyond studies on "static" planar and curved interfaces (e.g. aqueous interfaces with lanthanide salts, or extractants alone), we plan to investigate LL interfaces "in action", i.e. to follow the kinetics and spectroscopic signature of the multistep extraction processes. These studies involve experimental and theoretical developments. The results should serve as a basis for further understanding the extraction mechanism, to improve the efficiency and kinetics of existing processes, and to develop new ones. The methodological developments (e.g. "prediction" and interpretation of SHG signature, experimental set ups) will also allow to study other liquid interfaces (e.g. in phase transfer catalytic systems).