Related Experiment Video
Updated: Aug 18, 2026

Towards Biomimicking Wood: Fabricated Free-standing Films of Nanocellulose, Lignin, and a Synthetic Polycation
Published on: June 17, 2014
Moisture absorption and absorption kinetics in polyelectrolyte films: influence of film thickness
Bryan D Vogt1, Christopher L Soles, Hae-Jeong Lee
1Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA. bryan.vogt@nist.gov
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 degrees 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 ofthickness, 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.
Related Concept Videos
Factors Affecting Dissolution: Drug pKa, Lipophilicity and GI pH
A drug's pKa and the pH of the gastrointestinal (GI) tract play crucial roles in drug...
Determination of Molar Masses of Polymers II
Factors Influencing Drug Absorption: Physicochemical Parameters
Enhanced drug absorption can be achieved by reducing particle sizes and increasing surface areas, thereby facilitating...
Factors Influencing Drug Absorption: Pharmaceutical Parameters
Factors Influencing Drug Absorption: Drug Dissolution
Factors Affecting Dissolution: Polymorphism, Amorphism and Pseudopolymorphism
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...

