Molecular simulation of crystal growth in long alkanes
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| Title: | Molecular simulation of crystal growth in long alkanes |
|---|---|
| Authors: | Waheed, N.1, Ko, M.J.1, Rutledge, G.C. rutledge@mit.edu |
| Source: | Polymer. Sep2005, Vol. 46 Issue 20, p8689-8702. 14p. |
| Subjects: | Crystal growth, Crystallization, Molecular dynamics, Thermodynamics, Molecular weights |
| Abstract: | Abstract: We report crystal growth rate data from the melt for C50 and C100 obtained from non-equilibrium molecular dynamics simulations. This extends our previous results for n-eicosane (C20) [Waheed et al. J Chem Phys 2002;116:2301]. We also construct a crystal growth model that accounts for the thermodynamic driving force and relaxation time, using WLF theory and a small number of chemically specific quantities that can be estimated from molecular dynamics simulations. Our model can predict growth rates as a function of temperature and molecular weight, up to the entanglement molecular weight. Qualitatively, we see frequent adsorption and desorption of chain segments on the surface in both C50 and C100 systems. We find evidence for a surface nucleus involving 4–5 chain segments that are approximately 20 beads long, shorter than the ultimate thickness of the chain stem in the crystal, and involving segments from multiple chains. Treatment of relaxation dynamics using the Rouse model and the reptation model does not yield a statistically significant difference within the limits of our data, but the Rouse-based fit yields thermodynamic parameters that are in closer accord with those found from fits to experiments. [Copyright &y& Elsevier] |
| Copyright of Polymer is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 18263109 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Molecular simulation of crystal growth in long alkanes – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Waheed%2C+N%2E%22">Waheed, N.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Ko%2C+M%2EJ%2E%22">Ko, M.J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Rutledge%2C+G%2EC%2E%22">Rutledge, G.C.</searchLink><i> rutledge@mit.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Polymer%22">Polymer</searchLink>. Sep2005, Vol. 46 Issue 20, p8689-8702. 14p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Crystal+growth%22">Crystal growth</searchLink><br /><searchLink fieldCode="DE" term="%22Crystallization%22">Crystallization</searchLink><br /><searchLink fieldCode="DE" term="%22Molecular+dynamics%22">Molecular dynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Thermodynamics%22">Thermodynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Molecular+weights%22">Molecular weights</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Abstract: We report crystal growth rate data from the melt for C50 and C100 obtained from non-equilibrium molecular dynamics simulations. This extends our previous results for n-eicosane (C20) [Waheed et al. J Chem Phys 2002;116:2301]. We also construct a crystal growth model that accounts for the thermodynamic driving force and relaxation time, using WLF theory and a small number of chemically specific quantities that can be estimated from molecular dynamics simulations. Our model can predict growth rates as a function of temperature and molecular weight, up to the entanglement molecular weight. Qualitatively, we see frequent adsorption and desorption of chain segments on the surface in both C50 and C100 systems. We find evidence for a surface nucleus involving 4–5 chain segments that are approximately 20 beads long, shorter than the ultimate thickness of the chain stem in the crystal, and involving segments from multiple chains. Treatment of relaxation dynamics using the Rouse model and the reptation model does not yield a statistically significant difference within the limits of our data, but the Rouse-based fit yields thermodynamic parameters that are in closer accord with those found from fits to experiments. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Polymer is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.polymer.2005.02.130 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 14 StartPage: 8689 Subjects: – SubjectFull: Crystal growth Type: general – SubjectFull: Crystallization Type: general – SubjectFull: Molecular dynamics Type: general – SubjectFull: Thermodynamics Type: general – SubjectFull: Molecular weights Type: general Titles: – TitleFull: Molecular simulation of crystal growth in long alkanes Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Waheed, N. – PersonEntity: Name: NameFull: Ko, M.J. – PersonEntity: Name: NameFull: Rutledge, G.C. IsPartOfRelationships: – BibEntity: Dates: – D: 23 M: 09 Text: Sep2005 Type: published Y: 2005 Identifiers: – Type: issn-print Value: 00323861 Numbering: – Type: volume Value: 46 – Type: issue Value: 20 Titles: – TitleFull: Polymer Type: main |
| ResultId | 1 |
