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.