Menghua Zhao
Sciences et Ingénierie de la Matière Molle – UMR 7615, ESPCI PARIS-Université PSL
https://sites.google.com/view/zhao-menghua/welcome-page
Probing ionic transport in tunable angstrom-size water film
Liquid/ion transport at the nanoscale is encountered in many natural processes and molecular biology. Understanding these processes is crucial for designing efficient membranes for desalination, filtration, or osmotic energy harvesting. However, current systems with manipulations of flow at the ultimate molecular length scale are still lacking, with only a few designs restricted to specific materials, mostly hydrophobic ones. Further understanding of hydrophilic nanometric channels is missing. In this seminar, I will demonstrate how we overcome previous technological limitations by developing a new experiment that allows us to investigate ionic transport in subnanometric water films, with thicknesses continuously controlled between 0.3 and 2 nm. I will then present a continuum description of the transport of ions in such a confined environment and reveal a non-conductive single molecular layer close to the liquid-solid interface. These results provide new insights to model nanofluidic transport at the nanoscale and open new routes to design nanofluidic devices.