Characterization of the structures and dynamics of phosphoric acid doped benzimidazole mixtures: a molecular dynamics study

TitleCharacterization of the structures and dynamics of phosphoric acid doped benzimidazole mixtures: a molecular dynamics study
Publication TypeJournal Article
Year of Publication2013
AuthorsMore, M, Pahari, S, Roy, S, Venkatnathan, A
JournalJournal of Molecular Modeling
Volume19
Issue1
Pagination109-118
Date PublishedJAN
ISSN1610-2940
KeywordsDiffusion coefficient, Hydrogen bond, molecular dynamics, Radial distribution functions
Abstract

Benzimidazole-based polymer membranes like poly(2,5-benzimidazole) (ABPBI) doped with phosphoric acid (PA) are electrolytes that exhibit high proton conductivity in fuel cells at elevated temperatures. The benzimidazole (BI) moiety is an important constituent of these membranes, so the present work was performed in order to achieve a molecular understanding of the BI-PA interactions in the presence of varying levels of the PA dopant, using classical molecular dynamics (MD) simulations. The various hydrogen-bonding interactions, as characterized based on structural properties and hydrogen-bond lifetime calculations, show that both BI and PA molecules exhibit dual proton-acceptor/donor functionality. An examination of diffusion coefficients showed that the diffusion of BI decreases with increasing PA uptake, whereas the diffusion of PA slightly increases. The hydrogen-bond lifetime calculations pointed to the existence of competitive hydrogen bonding between various sites in BI and PA.

DOI10.1007/s00894-012-1519-8
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)1.867
Divison category: 
Physical and Materials Chemistry