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Molecular simulations at extreme experimental conditions: Application of advanced methods to geochemistry
Principal researcher: M. Lisal, Inst. Chem. Process Fund.,
Acad. Sci., Prague
[Supported by the "Information Society Programme" (2005-2009)]
(back-to-list-of-projects)
SUMMARY
The project deals with the development and subsequent applications of new methods
and algoritms for computer modeling and molecular simulations in geochemistry,
particularly for geological fluid systems at extreme experimental conditions. The
target of the research are (1) state and phase behavior of geological fluids at
high temperatures and high pressures, and (2) physico-chemical properties of
geological fluid systems at porous media. The goal of the project is the development
of molecular simulation methodology for high-density chemically-reacting fluid
systems in bulk and confinement. The applied methodology starts with the development
and optimization of appropriate models and algorithms that are followed by the
investigation of the models and assessment of the results and ends with applications
of the models to selected geological problems.
Molecular-level simulations of chemically-reacting fluids in nanoporous materials
Principal researcher: M. Lisal, Inst. Chem. Process Fund.,
Acad. Sci., Prague
[Supported by the Grant Agency of the Czech Republic
(2005-2007)]
(back-to-list-of-projects)
SUMMARY
The aim of the proposed project is to explore, by molecular-level simulations, the behavior of
chemically-reacting fluids in nanoporous materials. Such behavior is very difficult and in some
cases even impossible to determine experimentally. The project considers nanomaterial models of
different levels of realism, ranging from simple nanopores or single carbon nanotubes to networked
structures of pores or disordered random nanoporous media. The focus of this work is on the effects
of nanoporous material disorder and reduced dimensionality on the reaction equilibrium, on the
relation between the adsorption and binding behavior of individual mixture components and chemical
reactions, and on the effects of confinement on reaction kinetics. Some of these phenomena depend
strongly on how fluid particles travel inside the nanoporous space. Therefore, one of the main
efforts will be concentrated on the incorporation of realistic mass transport mechanisms into models
of confined chemical reactions. The project further provides a means of determining the properties
of nanoreactor systems, thus, facilitating the implementation of nanoscale chemical devices. An
integral part of the project is also the development of several novel simulation methodologies to
calculate the properties of chemically-reacting fluids in the nanoporous materials.
Prediction of solubility for large molecules in solvents by parallelized molecular simulation methods
Principal researcher: M. Lisal, Inst. Chem. Process Fund.,
Acad. Sci., Prague
[Supported by the Grant Agency of the Academy of Sciemces (2003-2005)]
(back-to-list-of-projects)
SUMMARY
We will develop parallelized simulation methods for calculation of chemical potential of
large molecules. The parallelized simulation method will be developed on the basis of
advanced simulation methods such as the Kirkwood coupling parameter method, the
single-charging integral method, the configurational-bias method, the test-segment-insertion
method and the expanded ensemble method. The methods will be implemented on parallel
computers with distributed memory using the Message Passing Interface library. The parallelized
simulation methods will be applied to prediction of solubilities of large molecules in different
solvents. Examples are solubility of MTBE in water or solubility of organo-metallic compounds in
supercritical carbon dioxide and supercritical water.
Molecular modeling of supercritical carbon dioxide-surfactant-solute systems
Principal researcher: M. Lisal, Inst. Chem. Process Fund.,
Acad. Sci., Prague
[Supported by the Grant Agency of the Czech Republic (2002-2004)]
(back-to-list-of-projects)
SUMMARY
The aim of the proposed project is to substantially improve the description of the micellar
behavior of novel fluorinated surfactants in supercritical carbon dioxide. Supercritical
carbon dioxide is becoming a commonly-used solvent due to its low cost, moderate critical
conditions and environmentally benign nature. The novel fluorinated surfactants are able to
improve the solubility of normally insoluble subtances such as water and polymers in
supercritical carbon dioxide. The micellar behavior will be studied by molecular simulations
and a multiple equilibrium model combined with molecular-level theories. The molecular
simulations will be performed on our modification of Larson's lattice model and discretized
lattice models. The molecular simulations will focus on providing a global picture of the
effect of solvent density, temperature, concentration, surfactant architecture and type of
solutes on the micellar behavior. The multiple equilibrium model will utilize the information
from the molecular simulations and the goal will be to provide the analytical expressions for
the standard chemical potentials and the activity coefficients of micelles, which can be used
in practical calculations and predictions.
