scholarly journals Effects of the CO2 Guest Molecule on the sI Clathrate Hydrate Structure

Materials ◽  
2016 ◽  
Vol 9 (9) ◽  
pp. 777 ◽  
Author(s):  
Fernando Izquierdo-Ruiz ◽  
Alberto Otero-de-la-Roza ◽  
Julia Contreras-García ◽  
Olga Prieto-Ballesteros ◽  
Jose Recio
Keyword(s):  
Guest Molecule ◽  
Clathrate Hydrate

Ordering of guest-molecule dipoles in the structure I clathrate hydrate of trimethylene oxides

1974 ◽  
Vol 3 (2) ◽  
pp. 239-247 ◽  
Author(s):  
S.R. Gough ◽  
S.K. Garg ◽  
D.W. Davidson
Keyword(s):  
Guest Molecule ◽  
Clathrate Hydrate

Structural Transition of Trimethylamine Hydrate by Methane or Hydrogen Inclusion

2020 ◽  
Author(s):  
Minjun Cha
Keyword(s):  
Structural Transition ◽  
Guest Molecule ◽  
Clathrate Hydrate ◽  
Hydrogen Gas ◽  
Time Dependent ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Inclusion Process ◽  
Diffraction Patterns

<p>Recently, several alkylamine hydrates have been studied in an effort to reveal the structural transitions from semi- to ‘canonical’ clathrate hydrate in the presence of secondary guest molecules. Trimethylamine (TMA) is known to form the semi-clathrate hydrate, and it has been reported that the structural transition of the TMA semi-clathrate hydrate may not occur in the presence of hydrogen gas as a secondary guest molecule. This paper reports the structural transition of trimethylamine(TMA) hydrate induced by the type of guest molecules. Powder X-ray diffraction patterns of (TMA + H<sub>2</sub>) hydrates show the formation of hexagoanl P6/mmm hydrate, but those of (TMA + CH<sub>4</sub>) hydrates indicate the formation of cubic Fd3m hydrate. Without gaseous guest molecule, the crystal structure of pure TMA hydrate is identified as hexagonal P6/mmm. Therefore, inclusion of gaseous methane in TMA hydrate can induce the structural transition from hexagonal to cubic hydrate or the formation of metastable cubic hydrate. To clearly reveal this possibility, we also check the time-dependent structural patterns of binary (TMA + CH<sub>4</sub>) hydrates from 1 to 14 days, and the results show that the structural transition of TMA hydrate from hexagonal P6/mmm to cubic Fd3m hydrate structure can occur during the methane inclusion process.</p>

scholarly journals Elasticity and Stability of Clathrate Hydrate: Role of Guest Molecule Motions

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jihui Jia ◽  
Yunfeng Liang ◽  
Takeshi Tsuji ◽  
Sumihiko Murata ◽  
Toshifumi Matsuoka
Keyword(s):  
Guest Molecule ◽  
Clathrate Hydrate

Managing Hydrogen Bonding in the Clathrate Hydrate of the 1-Pentanol Guest Molecule

CrystEngComm ◽  
2021 ◽  
Author(s):  
Byeonggwan Lee ◽  
Jeongtak Kim ◽  
Kyuchul Shin ◽  
Ki Hun Park ◽  
Minjun Cha ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Guest Molecule ◽  
Clathrate Hydrate ◽  
Guest Molecules

It remains a difficult task to predict the hydrate structure and conformation of potential guest molecules in one of the three canonical hydrate lattices. 1-pentanol is characteristic of molecules that...

Proton and deuteron nuclear magnetic resonance study of host and guest motions in ethylene oxide-d4 clathrate hydrate

1976 ◽  
Vol 54 (23) ◽  
pp. 3677-3684 ◽  
Author(s):  
John A. Ripmeester
Keyword(s):  
Relaxation Time ◽  
Ethylene Oxide ◽  
Guest Molecule ◽  
Continuous Wave ◽  
Quadrupole Coupling Constant ◽  
Nuclear Magnetic Resonance Study ◽  
Clathrate Hydrate ◽  
Water Molecules ◽  
Time Data ◽  
And Diffusion

The motions of water molecules in ethylene oxide-d4 clathrate hydrate have been studied between 200 and 280 K using continuous wave and pulsed 1H nmr methods. The 1H second moment and rotating frame relaxation time variation with temperature show that reorientation and diffusion of water molecules occur as two distinct processes. From the relaxation time data, activation energies of 8.15 and 12.0 kcal/mol are found for reorientation and diffusion, respectively.From the non-zero guest molecule D quadrupole coupling constant observed between ∼100 and 280 K, it is evident that there is some net orientation of the guest molecules in the hydrate cages at all temperatures. Also, there is a slow motional averaging superimposed on the rapid guest molecule reorientation which can be described approximately by the same parameters as the water molecule reorientation.

Rapid Clathrate Hydrate Formation Using a Heavy Guest Molecule with Sodium Dodecyl Sulfate

2016 ◽  
Vol 55 (21) ◽  
pp. 6079-6084 ◽  
Author(s):  
Hyery Kang ◽  
Yun-Ho Ahn ◽  
Dong-Yeun Koh ◽  
Seungjun Baek ◽  
Jae W. Lee ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Guest Molecule ◽  
Sodium Dodecyl ◽  
Hydrate Formation ◽  
Clathrate Hydrate ◽  
Dodecyl Sulfate

Modeling Dissociation Pressure of Semi-Clathrate Hydrate Systems Containing CO2, CH4, N2, and H2S in the Presence of Tetra-n-butyl Ammonium Bromide

2019 ◽  
Vol 44 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Mohammad Mesbah ◽  
Ebrahim Soroush ◽  
Mashallah Rezakazemi
Keyword(s):  
Gas Phase ◽  
Mass Fraction ◽  
Guest Molecule ◽  
Clathrate Hydrate ◽  
Clathrate Hydrates ◽  
Ammonium Bromide ◽  
Guest Molecules ◽  
Dissociation Pressure ◽  
Tuning Parameters ◽  
Langmuir Adsorption

Abstract In this study, the phase equilibria of semi-clathrate hydrates of methane (CH4), carbon dioxide (CO2), nitrogen (N2), and hydrogen sulfide (H2S) in an aqueous solution of tetra-n-butyl ammonium bromide (TBAB) were modeled using a correlation based on a two-stage formation mechanism: a quasi-chemical reaction that forms basic semi-clathrate hydrates and adsorption of guest molecules in the linked cavities of the basic semi-clathrate hydrate. The adsorption of guest molecules was described by the Langmuir adsorption theory and the fugacity of the gas phase was calculated by Peng–Robinson (PR) equation of state (EOS). The water activity in the presence of TBAB was calculated using a correlation, dependent on temperature, the TBAB mass fraction, and the nature of the guest molecule. These equations were coupled together and form a correlation which was linked to a genetic algorithm for optimization of tuning parameters. The results showed an excellent agreement between model results and experimental data. In addition, an outlier diagnostic was performed for finding any possible doubtful data and assessing the applicability of the model. The results showed that more than 97 % of the data were reliable and they were in the applicability domain of the model.

Distortion of Host Lattice in Clathrate Hydrate as a Function of Guest Molecule and Temperature

2000 ◽  
Vol 104 (46) ◽  
pp. 10623-10630 ◽  
Author(s):  
Tomoko Ikeda ◽  
Shinji Mae ◽  
Osamu Yamamuro ◽  
Takasuke Matsuo ◽  
Susumu Ikeda ◽  
...  
Keyword(s):  
Guest Molecule ◽  
Host Lattice ◽  
Clathrate Hydrate
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