Confinement Effects on Mositure Absorption Kinetics in Polyelectrolyte Films
B D. Vogt, Christopher L. Soles, Hae-Jeong Lee, Eric K. Lin, Wen-Li Wu
Quartz crystal microbalance (QCM) measurements were used to determine the absorption of water into thin poly(4-ammonium styrenesulfonic acid) films from saturated vapor at 25 C. The effect of film thickness on the absorption kinetics was investigated in the range of thickness from 3 to 150 nm. The absorption follows Fickian behavior for films greater than 50 nm thick. For thinner films, a two-stage absorption model can fit the data. The deviation from Fickian behavior increases with increasing confinement. In addition to the change in absorption behavior, there is also significant decreases in the water diffusivity as the film thickness is decreased below 50 nm, with the water diffusivity into a 3 nm film more than three orders of magnitude less than the bulk.
Abstracts Of Papers Of The American Chemical Society
absorption, thin film
, Soles, C.
, Lee, H.
, Lin, E.
and Wu, W.
Confinement Effects on Mositure Absorption Kinetics in Polyelectrolyte Films, Abstracts Of Papers Of The American Chemical Society
(Accessed December 3, 2023)