Abstract: How water flows and changes phase in porous media dictates many natural and technological processes, from sap flow in plants to catalysis, drying, materials degradation or hydration of cement. In nanopores, transport and phase transitions are impacted by extreme confinement, and solutes such as salts further modify fluid behavior. In this presentation, I will discuss how water and salt solutions confined in porous materials with nanoscale pores respond to relative humidity (RH) variations, and show that RH may serve as a powerful control lever for externally tuning in-pore liquid dynamics. Through experiments on synthetic nanoporous media and bio/geo-mimetic structures, I will illustrate how condensation and evaporation in nanopores can induce capillary or osmotic flows, or trigger dramatic phase changes such as cavitation, salt crystal nucleation, or deliquescence. These observations have potential implications in various fields such as water harvesting, energy conversion, heritage and artwork preservation, optimization of cementitious materials, or humidity-responsive sensors and actuators.
Bio: Olivier Vincent is a physicist at CNRS, based at the Institut Lumière Matière (ILM) in Lyon, France. He earned his PhD in 2012 from Université Grenoble Alpes, then spent several years as a postdoctoral associate at Cornell University (USA). His current research combines experiments and modeling to investigate fluid behavior at small scales, exploring both thermodynamics and transport phenomena. His broader interests include micro/nanofluidics, porous media, soft matter physics, phase transitions, bubble dynamics and fluid flow in plant tissues.
ILM, CNRS, Université de Lyon 1