Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2009-4-6
pubmed:abstractText
Variations of the free volume, O2 permeability, and structure of the Nafion membrane upon ion exchange of H+ with Na+ and K+ were studied. The free volume was quantified using the positron annihilation lifetime (PAL) technique, whereas the polymer structure was characterized by dynamic mechanical analysis (DMA), nanoindentation, and wide-angle X-ray diffraction (WAXD). It was found that the ion exchange significantly expands the free volume and at the same time decreases the O2 permeability. This is opposed to the simple free volume model in which the structure with less open volume is more amenable to lower permeability. Comparison of experimental data collected by different techniques revealed that not only the free volume but also the polymer stiffness plays an essential role in O2 permeation.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Feb
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2247-52
pubmed:year
2009
pubmed:articleTitle
Effects of ion exchange on the free volume and oxygen permeation in Nafion for fuel cells.
pubmed:affiliation
FC-Cubic, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan. hamdy-mohamed@aist.go.jp
pubmed:publicationType
Journal Article