Reported here are theoretical calculations on the triflic acid and water, establishing molecular scale information necessary to modeling of the structure, thermodynamics, and ionic transport of Nafion membranes. To characterize side chain flexibility and accessibility of the acid proton, free energies for rotation of both carbon-sulfur and sulfur-oxygen (hydroxyl) bonds are presented. The energetic barrier to rotation of the acid proton away from the sulfonic acid oxygen plane is substantially flattened, with barrier less than one kcal/mol, by electrostatic solvation. The activation free energy for acid-water proton interchange is about 4.7 kcal/mol.
@article{arxiv.physics/9706028,
title = {Molecular Modeling of Trifluoromethanesulfonic Acid for Solvation Theory},
author = {Stephen J. Paddison and Lawrence R. Pratt and Thomas Zawodzinski and David W. Reagor},
journal= {arXiv preprint arXiv:physics/9706028},
year = {2009}
}
Comments
Five pages (LaTeX) and four figures. Thirteenth Symposium on Thermophysical Properties, NIST, Boulder, CO USA, June 22 - 27, 1997. Submitted to Fluid Phase Equilibrium