Molecular dynamics simulation of diffusion and structure of n -alkane/ n -alkanol mixtures at infinite dilution
| Autor: | Haimin Zhong, Canjian Liang, Liuping Chen, Jinyang Wang, Xiaojuan Chen |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Alkane
chemistry.chemical_classification 010304 chemical physics Diffusion Thermodynamics Atmospheric temperature range 010402 general chemistry Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Dilution Solvent Molecular dynamics chemistry Computational chemistry 0103 physical sciences Materials Chemistry Radius of gyration Molecule Physical and Theoretical Chemistry Spectroscopy |
| Zdroj: | Journal of Molecular Liquids. 223:489-496 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2016.08.091 |
| Popis: | Infinite dilute diffusion coefficients ( D 12 ) of normal alkanes (C1 to C14) in 1-octanol (C8-OH), as well as primary alkanols (C1-OH to C14-OH) in n-octane (C8) have been studied using molecular dynamics simulation in the temperature range from 298 to 374 K and at atmosphere pressure. Simulated D 12 values for short-chain solute molecules show a good agreement with the experimental ones taken from literature, while for the long-chain solute molecules the overestimation is large. Besides, the structures of solute molecules in above fluid mixtures are investigated by calculating radial distribution functions, radius of gyration, end-to-end distance, and root mean square fluctuation of atomic positions. These results confirm long-chain n -alkanes and n -alkanols molecules are curved and curled up, which we call it flexibility. Moreover, flexibilities for solute molecules (5 ≤ n ≤ 9) are symmetric but for much long-chain solute molecules like n-tetradecane (C14) and 1-tetradecanol (C14-OH) are asymmetric. We believe that strong chain-chain interactions are existed between different long-chain molecules, and it will result in the solute and solvent molecules are intertwisted. The serious overestimation of simulated D 12 for long-chain solute molecules can be reasonably explained by the intertwist effect. |
| Databáze: | OpenAIRE |
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