Molecular Dynamics Simulation of Surface Nucleation during Growth of an Alkane Crystal
| Autor: | Gregory C. Rutledge, Alexander J. Bourque, C. Rebecca Locker |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Quenching
chemistry.chemical_classification Materials science Polymers and Plastics Organic Chemistry Nucleation Crystal growth 02 engineering and technology Polymer Polyethylene 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Inorganic Chemistry Crystal Crystallography Molecular dynamics chemistry.chemical_compound chemistry Chemical physics Materials Chemistry Melting point 0210 nano-technology |
| Zdroj: | Macromolecules. 49:3619-3629 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/acs.macromol.5b02757 |
| Popis: | Crystal growth from the melt of n-pentacontane (C50) was studied by molecular dynamics simulation. Quenching below the melting temperature gives rise to propagation of the crystal growth front into the C50 melt from a crystalline polyethylene surface. By tracking the location of the crystal–melt interface, crystal growth rates between 0.02 and 0.05 m/s were observed, for quench depths of 10–70 K below the melting point. These growth rates compare favorably with those from a previous study by Waheed et al. [Polymer 2005, 46, 8689−8702]. Next, surface nucleation was identified with the formation of two-dimensional clusters of crystalline sites within layers parallel to the propagating growth front. Critical nucleus sizes, waiting times, and rates for surface nucleation were estimated by a mean first passage time analysis. A surface nucleation rate of ∼0.05 nm–2 ns–1 was observed, and it was nearly temperature-independent. Postcritical “spreading” of the surface nuclei to form a completely crystallized layer... |
| Databáze: | OpenAIRE |
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