title: Immobilization of a hyperbranched polyester via grafting-to and electron beam irradiation.
abstract: Stable thin films of an aromatic-aliphatic hyperbranched polyester with hydroxyl groups were fabricated on silicon substrates using electron beam irradiation and a grafting-to approach. We present a detailed study on the influence of the dose, dose rate, and temperature on the film properties and degradation behavior of the polyester immobilized by electron beam irradiation. A patterned polyester film was prepared on the substrate using a masking technique. In the second part of this work, we report on a method for the strong binding of the hyperbranched polyester onto the surface of an "activated" silicon substrate without using any coupling agent. The results are compared with the grafting-to of the hydroxyl-terminated polyester using thin PGMA anchoring layers ( Reichelt et al. Macromol. Symp. 2007, 254, 240- 247 ). The optimal conditions and mechanism of the anchoring procedures were investigated. The surface and film properties of all immobilized polymer films were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), electrokinetic measurements, contact-angle measurements by drop-shape analysis, spectroscopic and imaging ellipsometry, and infrared spectroscopy. It is shown that all immobilization methods can be optimized in such a way that the polymer surface properties remain unchanged compared to those of nongrafted polyesters.
authors.affiliation: Leibniz Institute of Polymer Research Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany.
authors.forename: Senta
authors.initials: S
authors.lastname: Reichelt
authors.forename: Uwe
authors.initials: U
authors.lastname: Gohs
authors.forename: Frank
authors.initials: F
authors.lastname: Simon
authors.forename: Sven
authors.initials: S
authors.lastname: Fleischmann
authors.forename: Klaus-Jochen
authors.initials: KJ
authors.lastname: Eichhorn
authors.forename: Brigitte
authors.initials: B
authors.lastname: Voit