ACS Appl Mater Interfaces
August 2015
Most gas barrier thin films suffer from cracking or plastic deformation when stretched, leading to significant loss of barrier. In an effort to make a stretchable gas barrier, which maintains low permeability when exposed to cyclic strain, we prepared layer-by-layer assemblies of tannic acid (TA) and poly(ethylene oxide) (PEO). A 40-bilayer (344 nm-thick) TA/PEO assembly maintained its oxygen transmission rate (6X lower than the 1.
View Article and Find Full Text PDFHydrogen bonded poly(acrylic acid) (PAA)/poly(ethylene oxide) (PEO) layer-by-layer assemblies are highly elastomeric, but more permeable than ionically bonded thin films. In order to expand the use of hydrogen-bonded assemblies to applications that require a better gas barrier, the effect of assembling pH on the oxygen permeability of PAA/PEO multilayer thin films was investigated. Altering the assembling pH leads to significant changes in phase morphology and bonding.
View Article and Find Full Text PDFUnlike ionically bonded or clay-loaded gas barrier thin films, which easily crack when moderately stretched, hydrogen-bonded poly(acrylic acid) (PAA)/poly(ethylene oxide) (PEO) multilayer thin films remain crack-free. Even after 100% strain, these nanocoatings provide more than a 5× reduction in oxygen transmission rate. This study shows that the lowest modulus PAA/PEO thin film is obtained at pH 3, but maintains a high barrier.
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