Mechanistic investigation of out-of-equilibrium adsorption processes

We aim to shed light on the mechanism of the out-of-the-equilibrium adsorption of nanoparticles at liquid interfaces. By employing aqueous dispersions consisting of negatively charged nanoparticles (NPs) decorated by cationic surfactants it is possible to tune the nanoparticle amphiphilicity via control of several parameters including the NP/surfactant bulk ratio, the surfactant structure and the ionic strength. As the NP desorption energy increases with the NP amphiphilicity, this system provides a versatile tool to investigate the adsorption of nanoscale objects with desorption energies spanning from few kBT to hundreds of kBT. Therefore, by structurally characterizing the NP monolayer formation via time-resolved grazing incidence small angle X-ray scattering (GISAXS), we will investigate, for the first time, how the adsorption mechanism changes when moving from quasi-equilibrium to far-from-the-equilibrium conditions.