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Martin TB, Gartner TE, Jones RL, Snyder CR, Jayaraman A. pyPRISM: A Computational Tool for Liquid-State Theory Calculations of Macromolecular Materials. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00011] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Tyler B. Martin
- National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | | | - Ronald L. Jones
- National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Chad R. Snyder
- National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
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Taylor MP, Ye Y, Adhikari SR. Conformation of a flexible polymer in explicit solvent: Accurate solvation potentials for Lennard-Jones chains. J Chem Phys 2015; 143:204901. [DOI: 10.1063/1.4935952] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mark P. Taylor
- Department of Physics, Hiram College, Hiram, Ohio 44234, USA
| | - Yuting Ye
- Department of Physics, Hiram College, Hiram, Ohio 44234, USA
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Ganesan V, Jayaraman A. Theory and simulation studies of effective interactions, phase behavior and morphology in polymer nanocomposites. SOFT MATTER 2014; 10:13-38. [PMID: 24651842 DOI: 10.1039/c3sm51864g] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Polymer nanocomposites are a class of materials that consist of a polymer matrix filled with inorganic/organic nanoscale additives that enhance the inherent macroscopic (mechanical, optical and electronic) properties of the polymer matrix. Over the past few decades such materials have received tremendous attention from experimentalists, theoreticians, and computational scientists. These studies have revealed that the macroscopic properties of polymer nanocomposites depend strongly on the (microscopic) morphology of the constituent nanoscale additives in the polymer matrix. As a consequence, intense research efforts have been directed to understand the relationships between interactions, morphology, and the phase behavior of polymer nanocomposites. Theory and simulations have proven to be useful tools in this regard due to their ability to link molecular level features of the polymer and nanoparticle additives to the resulting morphology within the composite. In this article we review recent theory and simulation studies, presenting briefly the methodological developments underlying PRISM theories, density functional theory, self-consistent field theory approaches, and atomistic and coarse-grained molecular simulations. We first discuss the studies on polymer nanocomposites with bare or un-functionalized nanoparticles as additives, followed by a review of recent work on composites containing polymer grafted or functionalized nanoparticles as additives. We conclude each section with a brief outlook on some potential future directions.
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Affiliation(s)
- Venkat Ganesan
- Department of Chemical Engineering, University of Texas, Austin, USA.
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Jayaraman A, Nair N. Integrating PRISM theory and Monte Carlo simulation to study polymer-functionalised particles and polymer nanocomposites. MOLECULAR SIMULATION 2012. [DOI: 10.1080/08927022.2012.683528] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Taylor MP, Adhikari SR. Conformation of a flexible chain in explicit solvent: Exact solvation potentials for short Lennard-Jones chains. J Chem Phys 2011; 135:044903. [DOI: 10.1063/1.3614500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Nair N, Wentzel N, Jayaraman A. Effect of bidispersity in grafted chain length on grafted chain conformations and potential of mean force between polymer grafted nanoparticles in a homopolymer matrix. J Chem Phys 2011; 134:194906. [DOI: 10.1063/1.3590275] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Nair N, Jayaraman A. Self-Consistent PRISM Theory−Monte Carlo Simulation Studies of Copolymer Grafted Nanoparticles in a Homopolymer Matrix. Macromolecules 2010. [DOI: 10.1021/ma101229r] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nitish Nair
- Department of Chemical and Biological Engineering, University of Colorado UCB 424, Boulder, Colorado 80309
| | - Arthi Jayaraman
- Department of Chemical and Biological Engineering, University of Colorado UCB 424, Boulder, Colorado 80309
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Frischknecht AL, McGarrity ES, Mackay ME. Expanded chain dimensions in polymer melts with nanoparticle fillers. J Chem Phys 2010; 132:204901. [DOI: 10.1063/1.3428760] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [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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Liu W, Bedrov D, Kumar SK, Veytsman B, Colby RH. Role of distributions of intramolecular concentrations on the dynamics of miscible polymer blends probed by molecular dynamics simulation. PHYSICAL REVIEW LETTERS 2009; 103:037801. [PMID: 19659319 DOI: 10.1103/physrevlett.103.037801] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Indexed: 05/09/2023]
Abstract
Using molecular dynamics simulations we show that a given monomer in a miscible polymer blend experiences broad distributions of both connectivity driven self-concentrations and thermodynamically controlled intermolecular concentration fluctuations. While these distributions should play a significant role in determining the constituent's dynamics across the whole concentration range, the distribution of self-concentrations is particularly important in the dilute limit, where intermolecular concentration fluctuations should be absent. These conclusions allow us to rationalize the recent literature results that report the apparent self-concentration determined in the dilute limit surprisingly depended on the blend partner.
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Affiliation(s)
- Wenjuan Liu
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Polson JM, Opps SB, Abou Risk N. Theoretical study of solvent effects on the coil-globule transition. J Chem Phys 2009; 130:244902. [DOI: 10.1063/1.3153350] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Antypov D, Elliott JA. Computer simulation study of a single polymer chain in an attractive solvent. J Chem Phys 2008; 129:174901. [DOI: 10.1063/1.2991178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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12
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Taylor MP, Petersen GM. Solvation potentials for flexible chain molecules in solution: on the validity of a pairwise decomposition. J Chem Phys 2008; 127:184901. [PMID: 18020661 DOI: 10.1063/1.2787006] [Citation(s) in RCA: 9] [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 effects of a solvent on the conformation of a flexible n-site solute molecule can be described formally in terms of an n-body solvation potential. Given the practical difficulty in computing such multibody potentials, it is common to carry out a pairwise decomposition in which the n-body potential is approximated by a sum of two-body potentials. Here we investigate the validity of this two-site approximation for short interaction-site chain-in-solvent systems. Using exact expressions for the conformation of an isolated chain, we construct a mapping between the full chain-in-solvent system and its solvation potential representation. We present results for both hard-sphere and square-well systems with n=5 that show that the two-site approximation is sufficient to completely capture the effects of an explicit solvent on chain conformation for a wide range of conditions (which include varying the solvent diameter in the hard-sphere system and varying the chain-solvent coupling in the square-well system). In all cases, a set of two-site potentials (one for each distinct site-site pair) is required. We also show that these two-site solvation potentials can be used to accurately compute a multisite intramolecular correlation function.
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Affiliation(s)
- Mark P Taylor
- Department of Physics, Hiram College, Hiram, Ohio 44234, USA.
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Polson JM, Moore NE. Simulation study of the coil-globule transition of a polymer in solvent. J Chem Phys 2006; 122:024905. [PMID: 15638628 DOI: 10.1063/1.1830435] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular dynamics simulations are used to study the coil-globule transition for a system composed of a bead-spring polymer immersed in an explicitly modeled solvent. Two different versions of the model are used, which are differentiated by the nature of monomer-solvent, solvent-solvent, and nonbonded monomer-monomer interactions. For each case, a model parameter lambda determines the degree of hydrophobicity of the monomers by controlling the degree of energy mismatch between the monomers and solvent particles. We consider a lambda-driven coil-globule transition at constant temperature. The simulations are used to calculate average static structure factors, which are then used to determine the scaling exponents of the system in order to determine the theta-point values lambdatheta separating the coil from the globule states. For each model we construct coil-globule phase diagrams in terms of lambda and the particle density rho. The results are analyzed in terms of a simple Flory-type theory of the collapse transition. The ratio of lambdatheta for the two models converges in the high density limit exactly to the value predicted by the theory in the random mixing approximation. Generally, the predicted values of lambdatheta are in reasonable agreement with the measured values at high rho, though the accuracy improves if the average chain size is calculated using the full probability distribution associated with the polymer-solvent free energy, rather than merely using the value obtained from the minimum of the free energy.
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Affiliation(s)
- James M Polson
- Department of Physics, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3, Canada
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Abstract
In the present study, we simulated a model system, PE in biphenyl, to gain the insight into the detailed solvation structures and the molecular mechanism of polymer chain solvation. Using atomistic molecular dynamics (MD) simulation, it was found that when the biphenyl is far from PE chain or in the bulk, the dihedral angle of the two rings in the solvent molecule are approximately 32 degrees. But, the dihedral angel is about 27 degrees when the biphenyls are very close to the PE chain. In the first solvation shell, the orientation angle of the biphenyl long axis to the chain segment backbone was found to be enhanced around two values: approximately 0 and approximately 60 degrees. The detailed solvation structures found here include all dyad conformations (TT, TG, TG', GT, GG, GG', G'T, G'G, and G'G') and vary as a function of the distance between PE chain and biphenyls in the first solvation shell. The closer the the solvent molecule to the PE segment, the higher the TT conformation fraction response is. The other dyad conformations such as TG, GG', etc. undergo different decreases, respectively. This study shows that the solvation even in the Theta condition makes the overall size expansion or the chain stretched. Such a cooperative change was examined here and found not due to generating or losing a conformational state but due to a change in conformational distribution. This change occurs in the middle location of the chain instead of the chain end locations.
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Affiliation(s)
- Qing Ji
- Polymer Physics Laboratory, National Laboratory of Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
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Zhao L, Li YG, Zhong C, Mi J. Structure and effective interactions in polymer nanocomposite melts: An integral equation theory study. J Chem Phys 2006; 124:144913. [PMID: 16626251 DOI: 10.1063/1.2187489] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The polymer reference interaction site model from integral equation theory is used to investigate the structure and effective interactions in polymer nanocomposite melts where strong nanoparticle-monomer interactions are principally considered in this work. For finite particle volume fraction, the compromise for the interference between polymers and nanoparticles results in an optimum particle volume fraction for nanoparticle dispersion in polymer melts. At constant particle volume fraction, the effects of degree of polymerization become insignificant when it reaches a threshold value, below which quantitative effects on the organization states of polymer nanocomposite melts are found and help nanoparticles to well disperse in polymer. The aggregation of large nanoparticles decreases with the increase of the nanoparticle-monomer attraction strength. These observations may provide useful information for the development of new polymer materials.
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Affiliation(s)
- Lei Zhao
- Department of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
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Frink LJD, Frischknecht AL. Density functional theory approach for coarse-grained lipid bilayers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:041923. [PMID: 16383436 DOI: 10.1103/physreve.72.041923] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Revised: 07/07/2005] [Indexed: 05/05/2023]
Abstract
Lipid bilayers are important inhomogeneous fluid systems that mediate the environment of cells and the interaction of cells with their environment. A variety of approaches have been taken to model the lipid molecules in bilayers, from all atom molecular dynamics to rigid body liquid crystals. In this paper we discuss the application of a density functional theory approach that treats the lipid molecules at the coarse-grained level of a freely jointed chain. This approach allows for compressibility effects, and can therefore be used to study not only the long range structure in lipid bilayers, but also the nanoscale structure induced in the bilayer when the lipids crystallize or when an inclusion (e.g., an embedded protein) is present. This paper presents a detailed analysis of fluid bilayers and lamellae predicted by the theory. In particular we locate solutions with zero surface tension. We calculate the phase diagram for all possible phases with planar symmetry, including uniform macrophases. Surprisingly, we find a first-order phase transition from the lamellar phase to an isolated bilayer phase on lowering the temperature. This transition appears to be driven by solvent packing effects. A further lowering of the temperature leads to a set of highly ordered bilayers.
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Schupper N, Shnerb NM. Inverse melting and inverse freezing: a spin model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:046107. [PMID: 16383468 DOI: 10.1103/physreve.72.046107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Indexed: 05/05/2023]
Abstract
Systems of highly degenerate ordered or frozen state may exhibit inverse melting (reversible crystallization upon heating) or inverse freezing (reversible glass transition upon heating). This phenomenon is reviewed, and a list of experimental demonstrations and theoretical models is presented. A simple spin model for inverse melting is introduced and solved analytically for infinite range, constant paramagnetic exchange interaction. The random exchange analogue of this model yields inverse freezing, as implied by the analytic solution based on the replica trick. The qualitative features of this system (generalized Blume-Capel spin model) are shown to resemble a large class of inverse melting phenomena. The appearance of inverse melting is related to an exact rescaling of one of the interaction parameters that measures the entropy of the system. For the case of almost degenerate spin states, perturbative expansion is presented, and the first three terms correspond to the empiric formula for the Flory-Huggins chi parameter in the theory of polymer melts. The possible microscopic origin of this chi parameter and the limitations of the Flory-Huggins theory where the state degeneracy is associated with the different conformations of a single polymer or with the spatial structures of two interacting molecules are discussed.
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Affiliation(s)
- Nurith Schupper
- Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
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Zhao L, Li YG, Mi J, Zhong C. Integral equation theory for atactic polystyrene melt with a coarse-grained model. J Chem Phys 2005; 123:124905. [PMID: 16392525 DOI: 10.1063/1.2038891] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this work, an integral equation approach to investigate the atactic polystyrene (aPS) melt based on polymer reference interaction site model (PRISM) theory is proposed. The intramolecular structure factors, required as input to PRISM theory, are obtained from the semiflexible chain model. With a novel coarse-graining procedure and the explicit-atom molecular-dynamics (MD) simulations for aPS, the parameters needed for the coarse-grained model are obtained by using an automatic simplex optimization. These parameters can be used to describe the structure and thermodynamic properties of the complex aPS melt and good agreement is obtained between the theory and MD simulations. The proposed integral equation approach provides a basis for describing the structure and properties of PS nanocomposites where the application of molecular simulation is difficult.
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Affiliation(s)
- Lei Zhao
- Department of Chemical Engineering, Key Laboratory of Bioprocess of Beijing, Beijing University of Chemical Technology, Beijing 100029, China
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McCoy JD, Curro JG. The colloidal force of bead-spring chains in a good solvent. J Chem Phys 2005; 122:164905. [PMID: 15945705 DOI: 10.1063/1.1884113] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A recently developed density functional theory (DFT) for tethered bead-spring chains is used to investigate colloidal forces for the good solvent case. A planar surface of tethered chains is opposed to a bare, hard wall and the force exerted on the bare wall is calculated by way of the contact density. Previously, the case of large wall separation was investigated. The density profiles of the unperturbed chains, in that case, were found to be neither stepfunctions nor parabolas and were shown to accurately predict computer simulation results. In the present paper, the surface forces that result from the distortion of these density profiles at finite wall separation is studied. The resulting force function is analyzed for varying surface coverages, wall separations, and chain lengths. The results are found to be in near quantitative agreement with the scaling predictions of Alexander [S. Alexander, J. Phys. (Paris) 38, 983 (1977)] when the layer thickness is "correctly" defined. Finally, a hybrid Alexander-DFT theory is suggested for the analysis of experimental results.
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Affiliation(s)
- John D McCoy
- Department of Materials and Metallurgical Engineering, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA.
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Müller M, Smith GD. Phase separation in binary mixtures containing polymers: A quantitative comparison of single-chain-in-mean-field simulations and computer simulations of the corresponding multichain systems. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/polb.20385] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Borodin O, Bedrov D, Smith GD, Nairn J, Bardenhagen S. Multiscale modeling of viscoelastic properties of polymer nanocomposites. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/polb.20390] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Taylor MP. Conformation of a polymer chain in solution: An exact density expansion approach. J Chem Phys 2004; 121:10757-65. [PMID: 15549961 DOI: 10.1063/1.1807831] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The conformation of a polymer chain in solution is intrinsically coupled to the thermodynamic and structural properties of the solvent. Here we study such solvent effects in a system consisting of a flexible interaction-site n-mer chain immersed in a monomeric solvent. Chain conformation is described with a set of intramolecular site-site probability functions. We derive an exact density expansion for these intramolecular probability functions and give a diagrammatic representation of the terms contributing at each order of the expansion. The expansion is tested for a short hard-sphere chain (n=3 or 4) with site diameter sigma in a hard-sphere solvent with solvent diameter D. In comparison with Monte Carlo simulation results for 0.2< or =D/sigma< or =100, the expansion (taken to second order) is found to be quantitatively accurate for low to moderate solvent volume fractions for all size ratios. Average chain dimensions are predicted accurately up to liquidlike solvent densities. The hard-sphere chains are compressed with both increasing solvent density and decreasing solvent size. For small solvent (D<sigma), depletion effects are found and the chain structure is strongly perturbed even at low solvent volume fractions.
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Affiliation(s)
- Mark P Taylor
- Department of Physics, Hiram College, Hiram, OH 44234, USA.
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Mendez S, Curro JG. Integral Equation Theory of Polymer Solutions: Application to Polyethylene/Benzene Solutions. Macromolecules 2004. [DOI: 10.1021/ma0355296] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergio Mendez
- University of New Mexico, Albuquerque, New Mexico 87131
| | - John G. Curro
- Sandia National Laboratories, Albuquerque, New Mexico 87185
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Smith GD, Bedrov D, Li L, Byutner O. A molecular dynamics simulation study of the viscoelastic properties of polymer nanocomposites. J Chem Phys 2002. [DOI: 10.1063/1.1516589] [Citation(s) in RCA: 228] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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McCoy JD, Ye Y, Curro JG. Application of density functional theory to tethered polymer chains: Athermal systems. J Chem Phys 2002. [DOI: 10.1063/1.1491242] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bedrov D, Smith GD, Freed KF, Dudowicz J. A comparison of self-assembly in lattice and off-lattice model amphiphile solutions. J Chem Phys 2002. [DOI: 10.1063/1.1461355] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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