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Kim HS, Kwon T, Park CB, Sung BJ. Temperature Dependence of Conformational Relaxation of Poly(ethylene oxide) Melts. Polymers (Basel) 2021; 13:4049. [PMID: 34833348 PMCID: PMC8618988 DOI: 10.3390/polym13224049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/12/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
The time-temperature superposition (TTS) principle, employed extensively for the analysis of polymer dynamics, is based on the assumption that the different normal modes of polymer chains would experience identical temperature dependence. We aim to test the critical assumption for TTS principle by investigating poly(ethylene oxide) (PEO) melts, which have been considered excellent solid polyelectrolytes. In this work, we perform all-atom molecular dynamics simulations up to 300 ns at a range of temperatures for PEO melts. We find from our simulations that the conformations of strands of PEO chains in melts show ideal chain statistics when the strand consists of at least 10 monomers. At the temperature range of T= 400 to 300 K, the mean-square displacements (⟨Δr2(t)⟩) of the centers of mass of chains enter the Fickian regime, i.e., ⟨Δr2(t)⟩∼t1. On the other hand, ⟨Δr2(t)⟩ of the monomers of the chains scales as ⟨Δr2(t)⟩∼t1/2 at intermediate time scales as expected for the Rouse model. We investigate various relaxation modes of the polymer chains and their relaxation times (τn), by calculating for each strand of n monomers. Interestingly, different normal modes of the PEO chains experience identical temperature dependence, thus indicating that the TTS principle would hold for the given temperature range.
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Affiliation(s)
| | | | | | - Bong June Sung
- Department of Chemistry, Sogang University, Seoul 04107, Korea; (H.S.K.); (T.K.); (C.B.P.)
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2
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Tsalikis DG, Koukoulas T, Mavrantzas VG, Pasquino R, Vlassopoulos D, Pyckhout-Hintzen W, Wischnewski A, Monkenbusch M, Richter D. Microscopic Structure, Conformation, and Dynamics of Ring and Linear Poly(ethylene oxide) Melts from Detailed Atomistic Molecular Dynamics Simulations: Dependence on Chain Length and Direct Comparison with Experimental Data. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02495] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Dimitrios G. Tsalikis
- Department
of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504, Patras, Greece
| | - Thanasis Koukoulas
- Department
of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504, Patras, Greece
| | - Vlasis G. Mavrantzas
- Department
of Chemical Engineering, University of Patras and FORTH-ICE/HT, GR 26504, Patras, Greece
- Particle
Technology Laboratory, Department of Mechanical and Process Engineering, ETH-Z, CH-8092 Zürich, Switzerland
| | - Rossana Pasquino
- FORTH, Institute
for Electronic Structure and Laser, Heraklion 71110, Greece
- Department
of Chemical, Materials and Industrial Engineering, University of Napoli Federico II, P.le Tecchio 80, 80125 Napoli, Italy
| | - Dimitris Vlassopoulos
- FORTH, Institute
for Electronic Structure and Laser, Heraklion 71110, Greece
- Department of Materials Science & Technology, University of Crete, Heraklion 71003, Greece
| | - Wim Pyckhout-Hintzen
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Andreas Wischnewski
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Michael Monkenbusch
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Dieter Richter
- Jülich
Centre for Neutron Science (JCNS-1) and Institute for Complex Systems
(ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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Papadopoulos GD, Tsalikis DG, Mavrantzas VG. Microscopic Dynamics and Topology of Polymer Rings Immersed in a Host Matrix of Longer Linear Polymers: Results from a Detailed Molecular Dynamics Simulation Study and Comparison with Experimental Data. Polymers (Basel) 2016; 8:E283. [PMID: 30974560 PMCID: PMC6432050 DOI: 10.3390/polym8080283] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/21/2016] [Accepted: 07/27/2016] [Indexed: 11/20/2022] Open
Abstract
We have performed molecular dynamics (MD) simulations of melt systems consisting of a small number of long ring poly(ethylene oxide) (PEO) probes immersed in a host matrix of linear PEO chains and have studied their microscopic dynamics and topology as a function of the molecular length of the host linear chains. Consistent with a recent neutron spin echo spectroscopy study (Goossen et al., Phys. Rev. Lett. 2015, 115, 148302), we have observed that the segmental dynamics of the probe ring molecules is controlled by the length of the host linear chains. In matrices of short, unentangled linear chains, the ring probes exhibit a Rouse-like dynamics, and the spectra of their dynamic structure factor resemble those in their own melt. In striking contrast, in matrices of long, entangled linear chains, their dynamics is drastically altered. The corresponding dynamic structure factor spectra exhibit a steep initial decay up to times on the order of the entanglement time τe of linear PEO at the same temperature but then they become practically time-independent approaching plateau values. The plateau values are different for different wavevectors; they also depend on the length of the host linear chains. Our results are supported by a geometric analysis of topological interactions, which reveals significant threading of all ring molecules by the linear chains. In most cases, each ring is simultaneously threaded by several linear chains. As a result, its dynamics at times longer than a few τe should be completely dictated by the release of the topological restrictions imposed by these threadings (interpenetrations). Our topological analysis did not indicate any effect of the few ring probes on the statistical properties of the network of primitive paths of the host linear chains.
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Affiliation(s)
- George D Papadopoulos
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, Patras, GR 26504, Greece.
| | - Dimitrios G Tsalikis
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, Patras, GR 26504, Greece.
| | - Vlasis G Mavrantzas
- Department of Chemical Engineering, University of Patras and FORTH-ICE/HT, Patras, GR 26504, Greece.
- Department of Mechanical and Process Engineering, Particle Technology Laboratory, ETH-Z, CH-8092 Zürich, Switzerland.
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4
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Vao-Soongnern V. A multiscale simulation model for poly(ethylene oxide). POLYMER SCIENCE SERIES A 2014. [DOI: 10.1134/s0965545x14060121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Hezaveh S, Samanta S, Milano G, Roccatano D. Structure and dynamics of 1,2-dimethoxyethane and 1,2-dimethoxypropane in aqueous and non-aqueous solutions: A molecular dynamics study. J Chem Phys 2011; 135:164501. [DOI: 10.1063/1.3643417] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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6
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Chaudhari MI, Pratt LR, Paulaitis ME. Communication: Direct observation of a hydrophobic bond in loop closure of a capped (-OCH2CH2-)n oligomer in water. J Chem Phys 2011; 133:231102. [PMID: 21186848 DOI: 10.1063/1.3521484] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The small r variation of the probability density P(r) for end-to-end separations of a -CH(2)CH(3) capped (-OCH(2)CH(2)-)(n) oligomer in water is computed to be closely similar to the CH(4)···CH(4) potential of mean force under the same circumstances. Since the aqueous solution CH(4)···CH(4) potential of mean force is the natural physical definition of a primitive hydrophobic bond, the present result identifies an experimentally accessible circumstance for direct observation of a hydrophobic bond which has not been observed previously because of the low solubility of CH(4) in water. The physical picture is that the soluble chain molecules carry the capping groups into aqueous solution, and permits them to find one another with reasonable frequency. Comparison with the corresponding results without the solvent shows that hydration of the solute oxygen atoms swells the chain molecule globule. This supports the view that the chain molecule globule might have a secondary effect on the hydrophobic interaction that is of first interest here. The volume of the chain molecule globule is important for comparing the probabilities with and without solvent because it characterizes the local concentration of capping groups. Study of other capping groups to enable x-ray and neutron diffraction measurements of P(r) is discussed.
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Affiliation(s)
- Mangesh I Chaudhari
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, USA.
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Xu Q, Mi J, Zhong C. Structure of poly(ethylene glycol)–water mixture studied by polymer reference interaction site model theory. J Chem Phys 2010; 133:174104. [DOI: 10.1063/1.3502108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Venturi G, Formisano F, Cuello GJ, Johnson MR, Pellegrini E, Bafile U, Guarini E. Structure of liquid n-hexane. J Chem Phys 2009; 131:034508. [DOI: 10.1063/1.3176413] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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10
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Fenn EE, Moilanen DE, Levinger NE, Fayer MD. Water dynamics and interactions in water-polyether binary mixtures. J Am Chem Soc 2009; 131:5530-9. [PMID: 19323522 PMCID: PMC2889155 DOI: 10.1021/ja809261d] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Poly(ethylene) oxide (PEO) is a technologically important polymer with a wide range of applications including ion-exchange membranes, protein crystallization, and medical devices. PEO's versatility arises from its special interactions with water. Water molecules may form hydrogen-bond bridges between the ether oxygens of the backbone. While steady-state measurements and theoretical studies of PEO's interactions with water abound, experiments measuring dynamic observables are quite sparse. A major question is the nature of the interactions of water with the ether oxygens as opposed to the highly hydrophilic PEO terminal hydroxyls. Here, we examine a wide range of mixtures of water and tetraethylene glycol dimethyl ether (TEGDE), a methyl-terminated derivative of PEO with 4 repeat units (5 ether oxygens), using ultrafast infrared polarization selective pump-probe measurements on water's hydroxyl stretching mode to determine vibrational relaxation and orientational relaxation dynamics. The experiments focus on the dynamical interactions of water with the ether backbone because TEGDE does not have the PEO terminal hydroxyls. The experiments observe two distinct subensembles of water molecules: those that are hydrogen bonded to other waters and those that are associated with TEGDE molecules. The water orientational relaxation has a fast component of a few picoseconds (water-like) followed by much slower decay of approximately 20 ps (TEGDE associated). The two decay times vary only mildly with the water concentration. The two subensembles are evident even in very low water content samples, indicating pooling of water molecules. Structural change as water content is lowered through either conformational changes in the backbone or increasing hydrophobic interactions is discussed.
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Affiliation(s)
- Emily E. Fenn
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | | | | | - Michael D. Fayer
- Department of Chemistry, Stanford University, Stanford, CA 94305
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Brodeck M, Alvarez F, Arbe A, Juranyi F, Unruh T, Holderer O, Colmenero J, Richter D. Study of the dynamics of poly(ethylene oxide) by combining molecular dynamic simulations and neutron scattering experiments. J Chem Phys 2009; 130:094908. [DOI: 10.1063/1.3077858] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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13
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Borodin O, Smith GD. Molecular Dynamics Simulations of Comb-Branched Poly(epoxide ether)-Based Polymer Electrolytes. Macromolecules 2007. [DOI: 10.1021/ma062128s] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Oleg Borodin
- Department of Materials Science & Engineering, 122 S. Central Campus Dr, Rm 304, University of Utah, Salt Lake City, Utah 84112-0560
| | - Grant D. Smith
- Department of Materials Science & Engineering, 122 S. Central Campus Dr, Rm 304, University of Utah, Salt Lake City, Utah 84112-0560
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Siqueira LJA, Ribeiro MCC. Molecular dynamics simulation of the polymer electrolyte poly(ethylene oxide)/LiClO4. II. Dynamical properties. J Chem Phys 2006; 125:214903. [PMID: 17166045 DOI: 10.1063/1.2400221] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamical properties of the polymer electrolyte poly(ethylene oxide) (PEO)LiClO(4) have been investigated by molecular dynamics simulations. The effect of changing salt concentration and temperature was evaluated on several time correlation functions. Ionic displacements projected on different directions reveal anisotropy in short-time (rattling) and long-time (diffusive) dynamics of Li(+) cations. It is shown that ionic mobility is coupled to the segmental motion of the polymeric chain. Structural relaxation is probed by the intermediate scattering function F(k,t) at several wave vectors. Good agreement was found between calculated and experimental F(k,t) for pure PEO. A remarkable slowing down of polymer relaxation is observed upon addition of the salt. The ionic conductivity estimated by the Nernst-Einstein equation is approximately ten times higher than the actual conductivity calculated by the time correlation function of charge current.
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Affiliation(s)
- Leonardo J A Siqueira
- Laboratório de Espectroscopia Molecular, Instituto de Química, Universidade de São Paulo, C.P. 26077, CEP 05513-970 São Paulo, SP, Brazil
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15
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Borodin O, Smith GD. Development of Many−Body Polarizable Force Fields for Li-Battery Components: 1. Ether, Alkane, and Carbonate-Based Solvents. J Phys Chem B 2006; 110:6279-92. [PMID: 16553446 DOI: 10.1021/jp055079e] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Classical many-body polarizable force fields were developed for n-alkanes, perflouroalkanes, polyethers, ketones, and linear and cyclic carbonates on the basis of quantum chemistry dimer energies of model compounds and empirical thermodynamic liquid-state properties. The dependence of the electron correlation contribution to the dimer binding energy on basis-set size and level of theory was investigated as a function of molecular separation for a number of alkane, ether, and ketone dimers. Molecular dynamics (MD) simulations of the force fields accurately predicted structural, dynamic, and transport properties of liquids and unentangled polymer melts. On average, gas-phase dimer binding energies predicted with the force field were between those from MP2/aug-cc-pvDz and MP2/aug-cc-pvTz quantum chemistry calculations.
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Affiliation(s)
- Oleg Borodin
- Department of Materials Science & Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
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16
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Genix AC, Arbe A, Alvarez F, Colmenero J, Willner L, Richter D. Dynamics of poly(ethylene oxide) in a blend with poly(methyl methacrylate): a quasielastic neutron scattering and molecular dynamics simulations study. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:031808. [PMID: 16241474 DOI: 10.1103/physreve.72.031808] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2005] [Revised: 06/20/2005] [Indexed: 05/05/2023]
Abstract
In this paper, we have addressed the question of the dynamic miscibility in a blend characterized by very different glass-transition temperatures, Tg, for the components: poly(ethylene oxide) and poly(methyl methacrylate) (PEO/PMMA). The combination of quasielastic neutron scattering with isotopic labeling and fully atomistic molecular dynamics simulations has allowed us to selectively investigate the dynamics of the two components in the picosecond-10 nanoseconds scale at temperatures close and above the Tg of the blend. The main focus was on the PEO component, i.e., that of the lowest Tg, but first we have characterized the dynamics of the other component in the blend and of the pure PEO homopolymer as reference. In the region investigated, the dynamics of PMMA in the blend is strongly affected by the alpha-methyl rotation; an additional process detected in the experimental window 65 K above the blend-Tg can be identified as the merged alphabeta process of this component that shows strong deviations from Gaussian behavior. On the other hand, pure PEO displays entropy driven dynamics up to very large momentum transfers. Such kind of motion seems to freeze when the PEO chains are in the blend. There, we have directly observed a very heterogeneous and moreover confined dynamics for the PEO component. The presence of the hardly moving PMMA matrix leads to the creation of little pockets of mobility where PEO can move. The characteristic size of such confined islands of mobility might be estimated to be of approximately 1 nm. These findings are corroborated by the simulation study, which has been an essential support and guide in our data analysis procedure.
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Affiliation(s)
- A-C Genix
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
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17
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The structure of poly(ethylene oxide) liquids: comparison of integral equation theory with molecular dynamics simulations and neutron scattering. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.03.123] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Siqueira LJA, Ribeiro MCC. Molecular dynamics simulation of the polymer electrolyte poly(ethyleneoxide)∕LiClO4. I. Structural properties. J Chem Phys 2005. [DOI: 10.1063/1.1899643] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wick CD, Theodorou DN. Connectivity-Altering Monte Carlo Simulations of the End Group Effects on Volumetric Properties for Poly(ethylene oxide). Macromolecules 2004. [DOI: 10.1021/ma049193r] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Collin D. Wick
- School of Chemical Engineering, Department of Materials Science and Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 15780 Athens, Greece
| | - Doros N. Theodorou
- School of Chemical Engineering, Department of Materials Science and Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 15780 Athens, Greece
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20
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Borodin O, Douglas R, Smith GD, Trouw F, Petrucci S. MD Simulations and Experimental Study of Structure, Dynamics, and Thermodynamics of Poly(ethylene oxide) and Its Oligomers. J Phys Chem B 2003. [DOI: 10.1021/jp0275387] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Oleg Borodin
- Department of Materials Science and Engineering, 122 S. Central Campus Drive, Rm. 304, University of Utah, Salt Lake City, Utah 84112, Manuel Lujan Jr. Neutron Scattering Center, MS H805, Los Alamos National Laboratory, New Mexico 87545, Department of Chemical and Fuels Engineering, University of Utah, Salt Lake City, Utah 84112, and Polytechnic University, Farmingdale, New York 11735
| | - Richard Douglas
- Department of Materials Science and Engineering, 122 S. Central Campus Drive, Rm. 304, University of Utah, Salt Lake City, Utah 84112, Manuel Lujan Jr. Neutron Scattering Center, MS H805, Los Alamos National Laboratory, New Mexico 87545, Department of Chemical and Fuels Engineering, University of Utah, Salt Lake City, Utah 84112, and Polytechnic University, Farmingdale, New York 11735
| | - Grant D. Smith
- Department of Materials Science and Engineering, 122 S. Central Campus Drive, Rm. 304, University of Utah, Salt Lake City, Utah 84112, Manuel Lujan Jr. Neutron Scattering Center, MS H805, Los Alamos National Laboratory, New Mexico 87545, Department of Chemical and Fuels Engineering, University of Utah, Salt Lake City, Utah 84112, and Polytechnic University, Farmingdale, New York 11735
| | - Frans Trouw
- Department of Materials Science and Engineering, 122 S. Central Campus Drive, Rm. 304, University of Utah, Salt Lake City, Utah 84112, Manuel Lujan Jr. Neutron Scattering Center, MS H805, Los Alamos National Laboratory, New Mexico 87545, Department of Chemical and Fuels Engineering, University of Utah, Salt Lake City, Utah 84112, and Polytechnic University, Farmingdale, New York 11735
| | - Sergio Petrucci
- Department of Materials Science and Engineering, 122 S. Central Campus Drive, Rm. 304, University of Utah, Salt Lake City, Utah 84112, Manuel Lujan Jr. Neutron Scattering Center, MS H805, Los Alamos National Laboratory, New Mexico 87545, Department of Chemical and Fuels Engineering, University of Utah, Salt Lake City, Utah 84112, and Polytechnic University, Farmingdale, New York 11735
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Smith GD, Borodin O, Bedrov D. A revised quantum chemistry-based potential for poly(ethylene oxide) and its oligomers in aqueous solution. J Comput Chem 2002; 23:1480-8. [PMID: 12370950 DOI: 10.1002/jcc.10166] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We have conducted a high-level quantum chemistry study of the interactions of 1,2-dimethoxyethane (DME) with water for complexes representing both hydrophilic and hydrophobic hydration. It was found that our previous quantum chemistry-based force field for poly(ethylene oxide) (PEO) and its oligomers in aqueous solution did a poor job in describing the hydrophobic binding of water to the ether, consistent with our recent calculations of the excess free energy and entropy of hydration of DME. Our original force field was revised to more accurately reproduce the interaction of water with the carboneous portions of DME. Molecular dynamics simulations of aqueous DME solutions using the revised quantum chemistry-based potential yielded good agreement with experiment for excess free energy, enthalpy, and volume as well as excess solution viscosity and the self-diffusion of water. Comparison with our original potential revealed that the relatively hydrophobic ether-water interactions in the new potential strongly reduced the favorable excess free energy and enthalpy but have relatively little influence on the excess entropy for dilute DME solutions. Other properties of DME and PEO solutions including conformational populations and dynamics, solution viscosity, hydrogen bonding, water translational and rotational diffusion and neutron structure factor as a function of solution composition were found to be largely unchanged from those obtained using the original potential.
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Affiliation(s)
- Grant D Smith
- Department of Materials Science and Engineering, University of Utah, 122 S. Central Campus Dr. Rm. 304, Salt Lake City, Utah 84112, USA.
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