[en] The desorption behaviour of the diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly ((dimethylamino)ethyl methacrylate), preadsorbed on silicon substrates was investigated under the influence of several desorption agents. The investigated polyampholyte is known to adsorb in regular structures directly from aqueous solutions onto silicon substrates. While the adsorption process is mainly determined by electrostatic interactions, two kinds of desorption mechanism should be assumed. The first mechanism is based on changed electrostatic conditions caused for instance by a strong change in pH of the aqueous solution. The other mechanism is observed after treatment with hydrophobic organic solvent, which leads to the desorption of hydrophobic adsorbed polyampholyte chains, while the electrostatically attached ones will not be influenced. To complete the desorption experiments with organic solvents also adsorption experiments from analogous polyampholytic solutions in the same organic solvents were performed. The amount of polymer at the substrate surface after adsorption or desorption experiments was determined using ellipsometry. Atomic force microscopy (AFM) was used to investigate the surface topography of dried samples after the desorption process.
Center for Education and Research on Macromolecules (CERM)
The DFG priority program “Polyelectrolyte” (grant IIC10-322 1009) ; Politique Scientifique Fédérale (Belgique) = Belgian Federal Science Policy ; Fondation Européenne de la Science = European Science Foundation - (ESF) in the frame of the SUPERNET program
The original publication is available at http://www.springerlink.com/content/r22011l1604j2736/fulltext.pdf. The authors acknowledge Journal of Polymer Research (Kluwer Academic Press) for allowing them to archive this paper.