Regensburg 2002 – scientific programme
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CPP: Chemische Physik und Polymerphysik
CPP 13: Poster: Funktionalisierte Polymere
CPP 13.5: Poster
Wednesday, March 13, 2002, 16:30–18:00, B
Adsorption properties of new thermoreversible co-polymers designed for multilayer self-assembly — •Mihaela Rusu1, Monika Schönhoff1, Sebastian Wohlrab1, and Dirk Kuckling2 — 1Max-Planck-Institute of Colloids and Interfaces Department of Interfaces;D-14424 Golm-Potsdam, Germany — 2Dresden University of Technology, Institute of Macromolecular Chemistry;D-01062 Dresden, Germany
A new type of co-polymers (PNIPY 112 and 102) consisting of a thermosensitive backbone of PNIPAAm and charged side chains of P2VP is investigated for two different molar ratios. These co-polymers provide properties of polyelectrolytes and of classical polyelectrolyte multilayers.
The coil-to-globule transition of both co-polymers in solution, as investigated by 1H NMR, occurs at different LCST. While PNIPY 112 shows a transition at 36∘C, the LCST of PNIPY102 is 40∘C. The elevation of the LCST can be attributed to the repulsive interaction between charged side chain, which hinders the rearrangement necessary for collapse. The adsorption properties of PNIPY 102 and PNIPY 112 are studied on planar surfaces and on colloidal particles, which were both pre-coated with four polyelectrotyte layers of alternating charge (PSS−, PDADMAC+). X-Ray reflectivity and ζ potential measurements monitor the adsorption of both co-polymers, and the adsorption isotherm is established by UV-VIS spectra of the supernatant. For the thermosensitive co-polymers which contains less charged side chains the phase transition is less affected, while that containing more charged side chains exhibit better adsorption properties and phase transition can be established in dependence of the side chain grafting density.