Polymer Engineering Faculty Research

Title

Moisture Absorption and Absorption Kinetics in Polyelectrolyte Films:â Influence of Film Thickness

Document Type

Article

Publication Date

Fall 2004

Abstract

Specular X-ray reflectivity (XR) and 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 and overall absorption was investigated in the range of thickness from (3 to 200) nm. The equilibrium swelling of all the films irrespective of film thickness was (0.57 ± 0.03) volume fraction. Although the equilibrium absorption is independent of thickness, the absorption rate substantially decreases for film thickness < 100 nm. For the thinnest film (3 nm), there is a 5 orders of magnitude decrease in the diffusion coefficient for water.

Volume

20

First Page

1453

Last Page

1458