In situ infrared ellipsometric study of stimuli-responsive mixed polyelectrolyte brushes

Yulia Mikhaylova; Leonid Ionov; Jörg Rappich; Michael Gensch; Norbert Esser; Sergiy Minko; Klaus-Jochen Eichhorn; Manfred Stamm; Karsten Hinrichs

doi:10.1021/ac070853a

In situ infrared ellipsometric study of stimuli-responsive mixed polyelectrolyte brushes

Anal Chem. 2007 Oct 15;79(20):7676-82. doi: 10.1021/ac070853a. Epub 2007 Sep 19.

Authors

Yulia Mikhaylova¹, Leonid Ionov, Jörg Rappich, Michael Gensch, Norbert Esser, Sergiy Minko, Klaus-Jochen Eichhorn, Manfred Stamm, Karsten Hinrichs

Affiliation

¹ ISAS-Institute for Analytical Sciences, Department Berlin, Albert-Einstein-Strasse 9, 12489 Berlin, Germany.

PMID: 17877422
DOI: 10.1021/ac070853a

Abstract

The switching behavior of stimuli-responsive mixed polymer brushes (d = 11 nm) was monitored for the first time in liquid phase in situ by infrared spectroscopic ellipsometry (IRSE). IRSE is presented as a new, sensitive in situ tool for online analysis of chemical changes in a thin complex film at the solid/liquid interface. Responsive behavior (protonation and deprotonation reaction) of the poly(acrylic acid)/poly(2-vinylpyridine) (PAA-mix-P2VP) brush was probed in aqueous solutions with pH ranging from pH 2 to pH 10. Structural and chemical changes in a thin polymer brush layer were identified from the analysis of infrared ellipsometric tanPsi spectra during the variation of pH. Systematic change in pH confirmed the reversible switching behavior of the PAA-mix-P2VP brush between three different states: swollen P2VP and compact PAA chains at pH 2, a compact "P2VP...PAA" complex at pH 6.5, and swollen PAA and compact P2VP chains at pH 10.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Electrolytes / chemistry*
Hydrogen-Ion Concentration
Molecular Structure
Spectrophotometry, Infrared / methods*

Substances

Electrolytes