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Hinrichs, K. ; Aulich, D. ; Esser, N. ; Minko, S. ; Hoy, O. ; Luzinov, I. ; Eichhorn, K.-J. ; Stamm, M.
In-situ infrared ellipsometry for the analysis of stimuli-responsive polymer brushes

Organic/silicon hybrid systems are of high relevance for the design of optical, electronic, biosensing and photovoltaic devices. Among all variety of smart materials, surface-immobilized polymer layers deserve a particular interest due to their unique switching properties. In the presented work the pH dependent switching behavior of stimuli-responsive mixed polymer brushes (d<12 nm) was monitored in liquid phase in-situ by infrared spectroscopic ellipsometry (IRSE) [1]. Structural and chemical changes are discussed for PAA, PAA-mix-P2VP and PEG/PS-mix-PAA brushes. The systematic change in pH confirmed the reversible switching behavior. For the PAA-mix-P2VP brush three different states are identified: Swollen P2VP plus compact PAA chains at pH 2, a compact "P2VPPAA" complex at pH 6.5, and swollen PAA plus compact P2VP chains at pH 10. [1] Mikhaylova Y., Ionov L., Rappich J., Gensch M., Esser N., Minko S., Eichhorn K.-J., Stamm M., Hinrichs K., Anal. Chem. 2007, 79, 7676.

Polymeric Materials: Science and Engineering 99



September 2008


Nanostructured Materials