Computational investigation of the influence of organic-aqueous interfaces on NaCl dissociation dynamics
- Louisiana Tech Univ., Ruston, LA (United States)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
NaCl pairing and dissociation was investigated at the CCl4-water and 1,2-dichloroethane (DCE)-water interfaces, and compared with dissociation results in the bulk and at the air-water interface utilizing polarizable potentials. The transition path sampling methodology was used to calculate the rate constant for dissociation, while umbrella sampling was used to map out a free energy profile for NaCl dissociation. The results found that ion pairing was weakest at the organic-water interfaces, even weaker than in the water bulk. This is in contrast to what has been observed previously for the air-water interface, in which NaCl ion paring is stronger than in the bulk [Wick, C.D. J. Phys. Chem. C, 2009, 113, 6356]. The consequence of the weaker binding at the organic-water interfaces was that ion dissociation was faster than in the other systems studied. Interactions of the organic phase with the ions influenced the magnitude of the Cl- dipole moment, and at the organic-water interfaces, the average Cl- dipole was found to be lower than at the air-water interface, weakening interactions with Na+. Work was performed at the Pacific Northwest National Laboratory (PNNL) was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy (DOE). PNNL is operated by Battelle for the DOE.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 971882
- Report Number(s):
- PNNL-SA-69544; JCPSA6; KC0301020; TRN: US201004%%334
- Journal Information:
- Journal of Chemical Physics, Vol. 132, Issue 4; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Anion Partitioning and Ion-Pairing Behavior of Anions in the Extraction of Cesium Salts by 4,5‘ ‘-Bis( tert -octylbenzo)dibenzo-24-crown-8 in 1,2-Dichloroethane
Molecular-level origin of the carboxylate head group response to divalent metal ion complexation at the air-water interface