Perfluoropolyethers: Development of an All-Atom Force Field for Molecular Simulations and Validation with New Experimental Vapor Pressures and Liquid Densities
- Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Vanderbilt Univ., Nashville, TN (United States). Multiscale Modeling and Simulation (MuMS)
- Univ. de Lisboa, Lisboa (Portugal). Centro de Química Estrutural, Inst. Superior Técnico
- Univ. de Lisboa, Lisboa (Portugal). Centro de Química Estrutural, Inst. Superior Técnico; Univ. de Évora, Évora (Portugal). Centro de Química de Évora
- Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Vanderbilt Univ., Nashville, TN (United States). Multiscale Modeling and Simulation (MuMS); Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemistry
A force field for perfluoropolyethers (PFPEs) based on the general optimized potentials for liquid simulations all-atom (OPLS-AA) force field has been derived in conjunction with experiments and ab initio quantum mechanical calculations. Vapor pressures and densities of two liquid PFPEs, perfluorodiglyme (CF3–O–(CF2–CF2–O)2–CF3) and perfluorotriglyme (CF3–O–(CF2–CF2–O)3–CF3), have been measured experimentally to validate the force field and increase our understanding of the physical properties of PFPEs. Force field parameters build upon those for related molecules (e.g., ethers and perfluoroalkanes) in the OPLS-AA force field, with new parameters introduced for interactions specific to PFPEs. Molecular dynamics simulations using the new force field demonstrate excellent agreement with ab initio calculations at the RHF/6-31G* level for gas-phase torsional energies (<0.5 kcal mol–1 error) and molecular structures for several PFPEs, and also accurately reproduce experimentally determined densities (<0.02 g cm–3 error) and enthalpies of vaporization derived from experimental vapor pressures (<0.3 kcal mol–1). Additional comparisons between experiment and simulation show that polyethers demonstrate a significant decrease in enthalpy of vaporization upon fluorination unlike related molecules (e.g., alkanes and alcohols). Simulation suggests this phenomenon is a result of reduced cohesion in liquid PFPEs due to a reduction in localized associations between backbone oxygen atoms and neighboring molecules.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC); US Dept. of Education
- Grant/Contract Number:
- AC02-05CH11231; ACI-1047828; ACI-1535150; P200A090323; UID/QUI/0100/2013; SFRH/BPD/81748/2011; PEst-OE/QUI/UI0619/2011
- OSTI ID:
- 1480285
- Journal Information:
- Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry, Vol. 121, Issue 27; ISSN 1520-6106
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Liquid-crystalline behavior and ion transport properties of block-structured molecules containing a perfluorinated ethylene oxide moiety complexed with a lithium salt
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journal | April 2018 |
Towards molecular simulations that are transparent, reproducible, usable by others, and extensible (TRUE)
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journal | April 2020 |
Towards molecular simulations that are transparent, reproducible, usable by others, and extensible (TRUE)
|
text | January 2020 |
Towards molecular simulations that are transparent, reproducible, usable by others, and extensible (TRUE)
|
text | January 2020 |
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