Berlin 2012 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 13: Poster: Interfaces and Thin Films
CPP 13.8: Poster
Tuesday, March 27, 2012, 18:15–20:45, Poster A
Stimuli-responsive layer-by-layer films containing block copolymer micelles — •Inna Dewald1, Julia Gensel1, Johann Erath1, Eva Betthausen2, Axel H.E. Müller2, and Andreas Fery1 — 11Physical Chemistry II, University of Bayreuth, 95440, Germany — 2Macromolecular Chemistry II, University of Bayreuth, 95440, Germany
We report on a novel approach for the design of stimuli-responsive thin films based on the incorporation of charged core-shell-corona micelles consisting of a hydrophobic core, a pH-responsive shell and a permanently charged cationic corona. [1,2] The films were produced using the layer-by-layer technique. Thereby the micelles were electrostatically self-assembled in an alternating manner using a strong anion as binding partner. Our results reveal that the assemblies exhibit fully reversible swelling transition due to pH-response of the weak polyelectrolyte middle block. The swelling behavior shows a strong dependence on solution pH and bilayer number. In order to characterize the multilayer films and analyze their pH-dependent behavior methods such as ellipsometry and atomic force microscopy were used. Measurements for both methods were performed on air as well as in liquid resulting in an up to ten-fold increase of the film thickness compared to the dry thickness. The films capacity of reversible swelling due to changes of solution pH makes our multilayer films excellent candidates for future applications in e.g. drug delivery with controlled release mechanism.
[1] E. Betthausen et al., Soft Matter, 2011, 7, 8880
[2] J. Gensel et al., Soft Matter, 2011, 7, 11144