Surface modification of thin polystyrene films |
| |
Authors: | D F Siqueira-Petri G Wenz P Schunk T Schimmel M Bruns M A Dichtl |
| |
Institution: | Instituto de Química Universidade de S?o Paulo P.O. Box 26077 05599-970 S?o Paulo-SP Brazil Fax: + 55-11-8155579 e-mail: dfsp@quim.iq.usp.br, BR Polymer Institut Universit?t Karlsruhe Hertzstrasse 16 D-76187 Karlsruhe Germany, DE Institut für Angewandte Physik Universit?t Karlsruhe D-76128 Karlsruhe Germany, DE Forschungszentrum Karlsruhe GmbH Institut für Instrumentelle Analytik P.O. Box 3640 D-76021 Karlsruhe Germany, DE Technische Universit?t München Physikdepartment Lehrstuhl fuer Biophysik E22 James-Franck-Strasse D-85747 Garching Germany, DE
|
| |
Abstract: | The sulfonation of polystyrene (PS) films with 50 and 96% sulfuric acid as a function of time is presented. In contrast to
previous literature reports, we showed that the treatment of PS films even with dilute sulfuric acid yields sulfonated surfaces
after reaction times of 30 s–1 h. The hydrophilicity of the modified PS increased considerably in comparison to the unreacted
PS films. X-ray photoelectron spectroscopy yielded evidence for the sulfonation of PS at the surface. Unreacted spin-coated
PS films were very smooth, while modified PS showed some clumps dispersed on a flat surface, as analyzed by atomic force microscopy.
The surface morphology was identified as a phase-separated system composed of domains of unreacted PS and a matrix of sulfonated
PS by fluorescence microscopy using the positively charged dye rhodamine B. The adsorption of the polycation diallyldimethylammonium
chloride on the sulfonated PS surface could be detected. The thickness of the adsorbed polycation was 2.2 nm.
Received: 3 November 1998 Accepted in revised form: 23 February 1999 |
| |
Keywords: | Polystyrene Sulfonation Surface analysis Adsorption Wet modification |
本文献已被 SpringerLink 等数据库收录! |