Coarse-grained simulations in the united-atom-model approximation are used to investigate confinement-induced morphological changes in Nafion-like ionomers. The system we study models a cylindrical pore in a hydrophobic matrix of supporting material with pore diameters that vary from 0.7 to 3.96 nm. Simulation results indicate a strong dependence of the equilibrium ionomer structures both on the pore diameter and on the sulfonate concentration in the pore. In the case of larger pores, the ionic clustering has the shape of a branched wire-like network oriented parallel to the pore axis. In the case of narrow pores, the ionic clusters occupy the pore center and exhibit strong density modulations both along the pore axis and across the pore diameter. The calculated diffusion coefficients for the ions indicate a sharp increase within the narrow pores. This finding is explained by ballistic-type ionic motion at shorter times and by the collective motion of ions in hydrophilic clusters. The influence of the hydrophobic walls on the distribution of ions and solvent molecules is discussed. (C) 2015 AIP Publishing LLC.
机构:
Comis Nacl Energia Atom, Dept Fis, Ave Libertador 8250, RA-1429 Buenos Aires, DF, ArgentinaComis Nacl Energia Atom, Dept Fis, Ave Libertador 8250, RA-1429 Buenos Aires, DF, Argentina
Elola, M. Dolores
Rodriguez, Javier
论文数: 0引用数: 0
h-index: 0
机构:
Comis Nacl Energia Atom, Dept Fis, Ave Libertador 8250, RA-1429 Buenos Aires, DF, Argentina
UNSAM, ECyT, Martin de Irigoyen 3100, RA-1650 San Martin, Buenos Aires, ArgentinaComis Nacl Energia Atom, Dept Fis, Ave Libertador 8250, RA-1429 Buenos Aires, DF, Argentina
机构:
Univ Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USAUniv Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA
Cordoba, Andres
Montes de Oca, Joan Manuel
论文数: 0引用数: 0
h-index: 0
机构:
Univ Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA
Argonne Natl Lab, Adv Mat Energy Water Syst AMEWS, Energy Frontier Res Ctr, Lemont, IL 60439 USAUniv Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA
Montes de Oca, Joan Manuel
Darling, Seth B.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA
Argonne Natl Lab, Adv Mat Energy Water Syst AMEWS, Energy Frontier Res Ctr, Lemont, IL 60439 USA
Argonne Natl Lab, Chem Sci & Engn Div, Lemont, IL 60439 USAUniv Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA
Darling, Seth B.
de Pablo, Juan J.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA
Argonne Natl Lab, Chem Sci & Engn Div, Lemont, IL 60439 USA
Argonne Natl Lab, Mat Sci Div, Lemont, IL 60439 USAUniv Chicago, Pritzker Sch Mol Engn, Chicago, IL 60637 USA