Defense of thesis: Olav Galteland

Defense of thesis 10 May: Olav Galteland – Faculty of Natural Sciences, NTNU

OLAV GALTELAND – THE DEPARTMENT OF CHEMISTRY

 

Olav Galteland has submitted the following academic thesis as part of the doctoral work at the Norwegian University of Science and Technology (NTNU):

“Nanothermodynamics and molecular simulations of fluids in porous media”

 

Assessment Committee

The Faculty of Natural Sciences has appointed the following Assessment Committee to assess the thesis:

·         Professor Guillaume Galliero. University of Pau. France

·         Professor Ignacio Pagonabarraga. University of Barcelona. Spain

·         Professor Erika Eiser. Department of Physics. NTNU

Professor Erika Eiser has been appointed Administrator of the Committee. The Committee recommends that the thesis is worthy of being publicly defended for the PhD degree. 

 

Supervisors

The doctoral work has been carried out at the Department of Chemistry, where Professor emerita Signe Kjelstrup at Department of Chemistry has been the candidate’s supervisor. Professor emeritus Bjørn Hafskjold and Professor emeritus Dick Bedeaux at Department of Chemistry have been the candidate’s co-supervisors. 

 

Public trial lecture:

Time: 10 May at 10:15

Place: R6, Floor u1, Realfagbygget, NTNU Gløshaugen

Prescribed subject: Microscopic and mesoscopic models for heat transport, pros and cons

 

Public defence of the thesis:

Time: 10 May at 13:15

Place: R6, Floor u1, Realfagbygget, NTNU Gløshaugen

 

Summary of thesis:

The thermodynamic and transport properties of fluids confined to porous media are in this thesis investigated with nanothermodynamics, non-equilibrium thermodynamics, and molecular simulations. Non-equilibrium thermodynamics is applied to describe the non-isothermal transport of a two-phase fluid in a representative elementary volume (REV) of a porous medium. The thermodynamic variables of the REV are defined, and the entropy production and flux-force equations are derived. The thermodynamic variables of the REV are constructed from additive contributions, namely from the bulks phases, surfaces, and three-phase contact lines. There are three driving forces present, the thermal force, a chemical force, and a pressure force. For nanoporous systems, we found that we need to introduce the integral pressure. The integral pressure is a concept from nanothermodynamics and is different from the differential pressure, which is the normal pressure. We realized with this work, that to calculate the driving force in non-equilibrium conditions, namely the pressure gradient, we first needed to compose a procedure to calculate the pressure of a porous medium. We calculated the thermodynamic properties of fluids in nanoporous media using nanothermodynamics. The thermodynamic properties we calculated were for example the integral pressure, surface tension, entropy, and disjoining pressure. We calculated the transport coefficients of a single-phase fluid in a fcc lattice of solid spheres. We assumed that the integral pressure is constant when the system is in equilibrium and used this to calculate the integral pressure in a bulk fluid in equilibrium with the porous media. From this, we constructed an equation of state which relates the fluid density of the porous medium, temperature, and porosity to the integral pressure. The gradient in integral pressure is the driving force for fluid flow. Together with the mass flux and shear viscosity, we calculated the hydraulic conductivity and permeability of the system.