Fast and Versatile Thermo-osmotic Flows with a Pinch of Salt
arXiv:2012.11571 · doi:10.1039/D1NR06998E
Abstract
Thermo-osmotic flows - flows generated in micro and nanofluidic systems by thermal gradients - could provide an alternative approach to harvest waste heat. However, such use would require massive thermo-osmotic flows, which are up to now only predicted for special and expensive materials. There is thus an urgent need to design affordable nanofluidic systems displaying large thermo-osmotic coefficients. In this paper we propose a general model for thermo-osmosis of aqueous electrolytes in charged nanofluidic channels, taking into account hydrodynamic slip, together with the different solvent and solute contributions to the thermo-osmotic response. We apply this model to a wide range of systems, by studying the effect of wetting, salt type and concentration, and surface charge. We show that intense thermo-osmotic flows can be generated using slipping charged surfaces. We also predict for intermediate wettings a transition from a thermophobic to a thermophilic behavior depending on the surface charge and salt concentration. Overall, this theoretical framework opens an avenue for controlling and manipulating thermally induced flows with common charged surfaces and a pinch of salt.
arXiv comment7 pages, 3 figures
References in corpus (11)
- Molecular transport through capillaries made with atomic-scale precision
- Transport in Charged Colloids Driven by Thermoelectricity
- Thermo-osmotic flow in thin films
- Liquid-solid slip on charged walls: dramatic impact of charge distribution
- What controls thermo-osmosis? Molecular simulations show the critical role of interfacial hydrodynamics
- Ion specificity and anomalous electrokinetic effects in hydrophobic nanochannels
- Molecular Simulation of Thermo-osmotic slip
- Thermoelectricity in confined liquid electrolytes
- Wall slip of complex fluids: interfacial friction or slip length?
- Giant thermoelectric response of nanofluidic systems driven by water excess enthalpy
- Hamiltonian transformation to compute Thermo-osmotic Forces