Seminar Cecilia Herrero (ILL, Grenoble)

Liquid-solid Friction at the Nanoscale: Harnessing Interfaces for Waste Heat Harvesting

Nanofluidics, the study of fluid transport at nanometer scale, is an emerging field offering innovative solutions to desalinate water, and to harvest energy or waste heat. At the nanoscale, surface effects become crucial: in particular liquid-solid slip, arising from a favorable ratio between viscosity and interfacial friction, can boost the performance of nanofluidic devices. In this seminar, I will show how molecular dynamics simulations can help us to unravel the molecular processes occurring at the nanoscale, starting from fundamental questions up to practical and promising applications. For instance, I will show that wall slip increases strongly when water is cooled down below its melting point, and investigate the origin of this unexpected effect. Then, I will show that intense thermo-osmotic flows (flows generated in micro and nanofluidic systems by thermal gradients) can be generated using slipping charged surfaces, making this type of electrokinetic phenomena industrially relevant for waste heat harvesting applications. Finally, I will also show how, for intermediate wettings, a transition from a thermophobic to a thermophilic behavior is predicted depending on the surface charge and salt concentration, opening a venue for controlling and manipulating thermally induced flows with common charged surfaces and a pinch of salt.