Rare earth metals are vital for high-tech applications in batteries, electronics, and in other devices linked to renewable energy. Due to rising demand and the associated supply risks, recycling has be-come a strategic priority. Liquid-liquid extraction is a key process for metal separation, but it faces sustainability challenges, including the use of volatile, non-sustainable solvents.
Liquid hybrid nanoparticles (LHNs) are an emerging class of next-generation systems that combine fluidity with the permanent porosity of solid adsorbents. Also referred as Type I porous liquids in the context of gas separation, they consist of hollow silica nanospheres, externally grafted with an organic corona for fluidity and compatibility, and that are internally functionalized with selective groups to target the capture of specific cations. Exploring such complex systems is challenging using purely experimental and trial-and-error approaches, so this PhD project aims to design LHNs using state-of-the-art molecular dynamics simulations, enabling detailed study of solvation, interfaces, and confinement at relevant time and size scales.
The key objectives of this PhD thesis are:
- To reveal the structural features of the organic corona determining the viscosity and hydrophobicity of LHNs;
- To study the interfaces between LHNs and aqueous solutions of metal ions to resolve liquid-liquid interfacial structure and transport across phases;
- To explore pore accessibility and preferential ab-sorption sites for the cations.
The methods used will include simulations with polarizable force fields, machine-learning interaction potentials, and quantum chemical calculations. The outcome of the project is expected to address important societal challenges related to sustainability, resource efficiency, and circular economy strategies.