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On a molecular theory of water
Jirsák, Jan ; Nezbeda, Ivo (advisor) ; Hrubý, Jan (referee) ; Kolafa, Jiří (referee) ; Jungwirth, Pavel (referee)
/ Summary Water is the most important liquid on Earth, but despite an errormous cffort put into research, it is not yet fully understood. A number of thermodyna- mic anomalies have been identified in water (e.g. the maximum of density at 4"C) and their occurrence intuitively linked to a strong intermolecular associ- ative force, i.e., hydrogen bonding. Nevertheiess, so far no rigorous molecular theory has been formulated. The present work attempts to propose and apply a rigorous statistical- -mechanical approach to water. The approach is based on recent findings that the structure of associating fluids is determined rnainly by the short-range forces (both repulsive ancl attractive). This fact enables us to apply the per- turbation theory taking a short-range model as a reference. The properties of the short-range reference model are then estimated by means of a simple, so-called primitive, model. Primitive models are anaiytically constructed to reproduce the structure of the short-range reference model keeping the in- teractions simple enough for theory. The contribution of the primitive model evaluated by Wertheim's TPT2 is used as a reference term in the perturbation expansion. The equation of state is then completed by adding dispersion and dipole-dipole correction terms. Main results of the work are as...
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On a molecular theory of water
Jirsák, Jan ; Nezbeda, Ivo (advisor) ; Hrubý, Jan (referee) ; Kolafa, Jiří (referee) ; Jungwirth, Pavel (referee)
/ Summary Water is the most important liquid on Earth, but despite an errormous cffort put into research, it is not yet fully understood. A number of thermodyna- mic anomalies have been identified in water (e.g. the maximum of density at 4"C) and their occurrence intuitively linked to a strong intermolecular associ- ative force, i.e., hydrogen bonding. Nevertheiess, so far no rigorous molecular theory has been formulated. The present work attempts to propose and apply a rigorous statistical- -mechanical approach to water. The approach is based on recent findings that the structure of associating fluids is determined rnainly by the short-range forces (both repulsive ancl attractive). This fact enables us to apply the per- turbation theory taking a short-range model as a reference. The properties of the short-range reference model are then estimated by means of a simple, so-called primitive, model. Primitive models are anaiytically constructed to reproduce the structure of the short-range reference model keeping the in- teractions simple enough for theory. The contribution of the primitive model evaluated by Wertheim's TPT2 is used as a reference term in the perturbation expansion. The equation of state is then completed by adding dispersion and dipole-dipole correction terms. Main results of the work are as...
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Molecular Simulation of Electrospinning.
Jirsák, Jan ; Moučka, F. ; Nezbeda, Ivo
Our recent attempts to apply standard molecular simulation techniques to the process of electrospinning are presented. We employ a molecular dynamics simulation to study phenomena involved in the electrospinning of polymer solutions, with particular attention to the formation of the Taylor cone and the development of a liquid jet. A molecular-based approach allows us to reveal the molecular structure and dynamics, which are inaccessible to continuum methods.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_22317031713170 - PDF
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Pokroky v popisu termodynamických vlastností soustav obsahujících alkanoly
Aim, Karel ; Nezbeda, Ivo
Two lines of research dealing with the applications of the so called primitive models (of association) to describe the thermodynamic properties of alkanolic systems will be outlined, namely (i) molecular simulations for the water and methanol mixtures, and (ii) equation of state developments for the alkanol and carbon dioxide systems. Molecular simulations on water–methanol mixtures were performed by using primitive models that descend from realistic models of molecular interaction for both compounds. The results for both the excess mixing and partial molar properties of the system over the entire concentration range were compared with the molecular simulation results for the commonly accepted complex realistic models (effective pair-wise potentials) and with experimental data.
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Nedávné pokroky v molekulárních simulacích termodynamického chování tekutých soustav.
Aim, Karel ; Lísal, Martin ; Nezbeda, Ivo ; Ungerer, P. ; Teuler, J.-M. ; Rousseau, B.
An overview of the recent developments in molecular computer simulation techniques used to calculate phase equilibria and thermodynamic properties of fluid systems is given. Particular attention is paid to the methodologies as follows: (i) reaction Gibbs ensemble Monte Carlo (RGEMC), which allows accurate phase equilibrium predictions for mixtures by employing experimental pure-component vapour pressure data in the computational procedure (ii) direct Monte Carlo simulation of Joule-Thomson processes, (iii) Monte Carlo simulations at fixed entropy, and (iv) an implemented parallelized sampling version of the Gibbs ensemble Monte Carlo (GEMC), which by-passes the physical transfer of complex molecules between boxes representing different phases by computing the chemical potential in an NVT ensemble (and is applicable also to flexible molecules). Example applications of the considered techniques for real fluid systems ar
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