Adsorption Kinetics of NIPAM-Based Polymers at the Air−Water Interface As Studied by Pendant Drop and Bubble Tensiometry

Autor: Vincent P. Gilcreest, Alexander V. Gorelov, Kenneth A. Dawson
Rok vydání: 2006
Předmět:
Zdroj: The Journal of Physical Chemistry B. 110:21903-21910
ISSN: 1520-5207
1520-6106
DOI: 10.1021/jp064112+
Popis: The adsorption of N-isopropylacrylamide (NIPAM) based thermoresponsive polymers at the air-water interface was investigated by using drop and bubble shape tensiometry. The molecular weight dependence of polymer adsorption rate was studied by using narrowly distributed polymer fractions (polydispersity < 1.2) that were prepared by solvent:nonsolvent fractionation. The time-dependent surface tension profiles were fitted to the Hua-Rosen equation and the t values obtained were applied for interpretation of the kinetic data. It was found that the rate of polymer adsorption increased as the molecular weight of the polymer decreased. The relationship between polymer surface concentration and surface tension was determined by applying the pendant drop as a Langmuir-type film balance. From this relationship, the kinetics of polymer adsorption determined experimentally was compared with the adsorption rates predicted by a diffusion-controlled adsorption model based on the Ward-Tordai equation. The predicted adsorption rates were in good agreement with what was found experimentally. The dependence of the adsorption rate on the molecular weight of polymers can be satisfactorily described within the diffusion-controlled model.
Databáze: OpenAIRE