title: Ab initio molecular dynamics simulations investigating proton transfer in perfluorosulfonic acid functionalized carbon nanotubes.
abstract: Proton dissociation and transfer were examined with ab initio molecular dynamics (AIMD) simulations of carbon nanotubes (CNT) functionalized with perfluorosulfonic acid (-CF(2)SO(3)H) groups with 1-3 H(2)O/SO(3)H. The CNT systems were constructed both with and without fluorine atoms covalently bound to the walls to elucidate the effects of the presence of a strongly hydrophobic environment, the fluorine, on proton dissociation, hydration, and stabilization. The simulations revealed that the dissociated proton was preferentially stabilized as a hydrated hydronium cation (i.e., Eigen like) in the fluorinated CNTs but as a Zundel (H(5)O(2)(+)) cation in the nonfluorinated CNTs. This feature is attributed to the fluorine atoms forming hydrogen bonds with the water molecules coordinated to the central hydronium ion.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Habenicht
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Paddison
authors.forename: Mark E
authors.initials: ME
authors.lastname: Tuckerman
mesh_terms: D005461:Fluorine / Q000737:chemistry; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009861:Onium Compounds / Q000737:chemistry; D011522:Protons
chemical_list: D005465:Fluorocarbon Polymers; D037742:Nanotubes, Carbon; D009861:Onium Compounds; D011522:Protons; D005461:Fluorine; C040402:perfluorosulfonic acid; C027727:hydronium ion