Abstract
The structure H (sH) clathrate hydrates of neo-hexane with argon, krypton, and methane help gases are synthesized to study the effect of the help gas on the crystal lattice structure. Powder X-ray diffraction (PXRD) measurements on these hydrates were performed for temperatures in the range of 93-183 K, and the a-axis and c-axis lattice constants and the small and medium sH cage occupancies were determined. The PXRD results show that the a-axis lattice constants of the three clathrate hydrates are close in magnitude, but at each temperature, for the c-axis lattice constants c(CH4) > c(Kr) > c(Ar). Parrinello-Rahman molecular dynamics (MD) simulations were performed on the three sH clathrate hydrate phases. The PXRD observed trends in the a-axis and c-axis lattice constants at different temperatures were reproduced by the simulations. The dynamics of the small cage guests are characterized by the velocity autocorrelation functions. The experiments and computations show the complex interplay of the molecular size and interaction energies in determining the lattice structure and stability of even relatively simple clathrate hydrates of nonpolar, hydrophobic molecules.
| Original language | English |
|---|---|
| Pages (from-to) | 21323-21330 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry C |
| Volume | 118 |
| Issue number | 37 |
| DOIs | |
| Publication status | Published - 2014 Sep 18 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Energy(all)
Cite this
Anisotropic lattice expansion of structure H clathrate hydrates induced by help guest : Experiments and molecular dynamics simulations. / Murayama, Kotaro; Takeya, Satoshi; Alavi, Saman; Ohmura, Ryo.
In: Journal of Physical Chemistry C, Vol. 118, No. 37, 18.09.2014, p. 21323-21330.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Anisotropic lattice expansion of structure H clathrate hydrates induced by help guest
T2 - Experiments and molecular dynamics simulations
AU - Murayama, Kotaro
AU - Takeya, Satoshi
AU - Alavi, Saman
AU - Ohmura, Ryo
PY - 2014/9/18
Y1 - 2014/9/18
N2 - The structure H (sH) clathrate hydrates of neo-hexane with argon, krypton, and methane help gases are synthesized to study the effect of the help gas on the crystal lattice structure. Powder X-ray diffraction (PXRD) measurements on these hydrates were performed for temperatures in the range of 93-183 K, and the a-axis and c-axis lattice constants and the small and medium sH cage occupancies were determined. The PXRD results show that the a-axis lattice constants of the three clathrate hydrates are close in magnitude, but at each temperature, for the c-axis lattice constants c(CH4) > c(Kr) > c(Ar). Parrinello-Rahman molecular dynamics (MD) simulations were performed on the three sH clathrate hydrate phases. The PXRD observed trends in the a-axis and c-axis lattice constants at different temperatures were reproduced by the simulations. The dynamics of the small cage guests are characterized by the velocity autocorrelation functions. The experiments and computations show the complex interplay of the molecular size and interaction energies in determining the lattice structure and stability of even relatively simple clathrate hydrates of nonpolar, hydrophobic molecules.
AB - The structure H (sH) clathrate hydrates of neo-hexane with argon, krypton, and methane help gases are synthesized to study the effect of the help gas on the crystal lattice structure. Powder X-ray diffraction (PXRD) measurements on these hydrates were performed for temperatures in the range of 93-183 K, and the a-axis and c-axis lattice constants and the small and medium sH cage occupancies were determined. The PXRD results show that the a-axis lattice constants of the three clathrate hydrates are close in magnitude, but at each temperature, for the c-axis lattice constants c(CH4) > c(Kr) > c(Ar). Parrinello-Rahman molecular dynamics (MD) simulations were performed on the three sH clathrate hydrate phases. The PXRD observed trends in the a-axis and c-axis lattice constants at different temperatures were reproduced by the simulations. The dynamics of the small cage guests are characterized by the velocity autocorrelation functions. The experiments and computations show the complex interplay of the molecular size and interaction energies in determining the lattice structure and stability of even relatively simple clathrate hydrates of nonpolar, hydrophobic molecules.
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U2 - 10.1021/jp5058786
DO - 10.1021/jp5058786
M3 - Article
VL - 118
SP - 21323
EP - 21330
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 37
ER -