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(260) Production(s) de FIRLEJ L.
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Molecular Dynamics study of tetracosane monolayers adsorbed on graphite
Auteur(s): Firlej L., Kuchta B, Roth M.w., Wexler C
Conference: ”, 11th International Conference “Electrical and Related Properties of Organic Solids”, ERPOS- (Piechowice, PL, 2008-07-13)
Ref HAL: hal-00820239_v1
Exporter : BibTex | endNote
Résumé: Molecular Dynamics (MD) simulations of tetracosane (C24H50) monolayer physisorbed on graphite are carried out. C24H50 molecules are simulated with explicit hydrogens and the graphite is represented by six graphene layers. We focus our analysis on the microscopic mechanism of melting, experimentally observed at T = 340 K. We are looking for the pre-melting transformations and analyze if there is a correlation between translational disordering of molecules and their internal degrees of freedom. We analyze several order parameters and their fluctuations along the MD trajectories. We show that the all atom representation of C24H50 is much more sensitive to the model of intramolecular interactions than united atom model. In particular two components: electrostatic forces and scaled 1-4 internal non-bonded interactions can shift melting temperature by several tenths of degree. A correlation between molecular stiffness and the intermolecular forces causes molecules’ footprint reduction during melting which involves a simultaneous lost of intramolecular and translational order. This cooperative mechanism is related to an abrupt increase of gauche defects within the central region of the chain.
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Modeling of alkanes adsorbed on graphite
Auteur(s): Firlej L., Kuchta B, Roth M.w., Wexler C
Conference: Modeling and Design of Molecular Materials 2008 (Piechowice, PL, 2008-06-23)
Ref HAL: hal-00820236_v1
Exporter : BibTex | endNote
Résumé: Molecular Dynamics (MD) simulations of tetracosane (C24H50) monolayer physisorbed on graphite are carried out. C24H50 molecules are simulated with explicit hydrogens and the graphite is represented by six graphene layers. We focus our analysis on the microscopic mechanism of melting, experimentally observed at T = 340 K. We are looking for the pre-melting transformations and analyze if there is a correlation between translational disordering of molecules and their internal degrees of freedom. We analyze several order parameters and their fluctuations along the MD trajectories. We show that the all atom representation of C24H50 is much more sensitive to the model of intramolecular interactions than united atom model. In particular two components: electrostatic forces and scaled 1-4 internal non-bonded interactions can shift melting temperature by several tenths of degree. A correlation between molecular stiffness and the intermolecular forces causes molecules’ footprint reduction during melting which involves a simultaneous lost of intramolecular and translational order. This cooperative mechanism is related to an abrupt increase of gauche defects within the central region of the chain.
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Molecular Dynamics
study of tetracosane monolayers adsorbed on graphite
Auteur(s): Roth M.w., Wexler C, Firlej L., Kuchta B
Conference: APS March Meeting 2008 (New Orleans, LA, US, 2008-03-10)
Ref HAL: hal-00820232_v1
Exporter : BibTex | endNote
Résumé: Molecular Dynamics (MD) simulations of tetracosane (C24H50) monolayer physisorbed on graphite are carried out. C24H50 molecules are simulated with explicit hydrogens and the graphite is represented by six graphene layers. We focus our analysis on the microscopic mechanism of melting, experimentally observed at T = 340 K. We are looking for the pre-melting transformations and analyze if there is a correlation between translational disordering of molecules and their internal degrees of freedom. We analyze several order parameters and their fluctuations along the MD trajectories. We show that the all atom representation of C24H50 is much more sensitive to the model of intramolecular interactions than united atom model. In particular two components: electrostatic forces and scaled 1-4 internal non-bonded interactions can shift melting temperature by several tenths of degree. A correlation between molecular stiffness and the intermolecular forces causes molecules’ footprint reduction during melting which involves a simultaneous lost of intramolecular and translational order. This cooperative mechanism is related to an abrupt increase of gauche defects within the central region of the chain.
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Gas adsorption in carbon nanotubes: classical versus quantum approach.
MC simulations
Auteur(s): Firlej L.
(Séminaires)
Department of Physics and Astronomy, University of Missouri, Columbia (Columbia, MO, FR), 2008-12-03 |
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New light on mechanism of phase transitions in nitrogen
adsorbed on graphite
Auteur(s): Golebiowska M., Firlej L., Kuchta B
(Séminaires)
Department of Physics and Astronomy, University of Missouri, Columbia (Columbia, MO, US), 2008-10-14 |
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Modeling of alkanes adsorbed on graphite
Auteur(s): Firlej L., Kuchta B, Roth M.w., Wexler C
(Séminaires)
Dept. of Physics, University of Missouri-Kansas City (Kansas City, US), 2008-09-26
Résumé: We present Molecular Dynamics (MD) simulations of tetracosane (C24H50) monolayer physisorbed on graphite. C24H50 molecules are simulated with explicit hydrogens and the graphite is represented by six graphene layers. We show that the all atom representation of C24H50 is much more sensitive to the model of intramolecular interactions than united atom model. In particular two components: electrostatic forces and scaled 1-4 internal non-bonded interactions can shift melting temperature by several tenths of degree.We focus our analysis on the microscopic mechanism of melting, experimentally observed at T = 340 K. We are looking for the pre-melting transformations and analyze if there is a correlation between translational disordering of molecules and their internal degrees of freedom. We analyze several order parameters and their fluctuations along the MD trajectories and show that correlation between molecular stiffness and the intermolecular forces causes molecules’ footprint reduction during melting which involves a simultaneous lost of intramolecular and translational order. This cooperative mechanism is related to an abrupt increase of gauche defects within the central region of the chain..
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Molecular dynamic study of tetracosane monolayer adsorbed on graphite
Auteur(s): Roth M.w., Firlej L., Wexler C, Kuchta B
(Séminaires)
Department of Physics and Astronomy, University of Missouri, Columbia (Columbia, MO, US), 2008-09-10 |