|Muthukrishnan, S.; Erhard, D.P.; Mori, H.; Müller, A.H.E.: Synthesis and Characterization of Surface-Grafted Hyperbranched Glycomethacrylates, Macromolecules, 39, 2743-2750 (2006) -- DOI: 10.1021/ma052575s|
Hyperbranched glycopolymers were grafted from a silicon wafer with a covalently attached initiator layer of α-bromoester fragments using self-condensing vinyl copolymerization (SCVCP) of the methacrylic AB* inimer, 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) and a sugar-carrying methacrylate, 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (MAIGlc) via atom transfer radical polymerization (ATRP). The film thickness and characteristic surface morphology were determined using ellipsometry and scanning force microscopy (SFM), respectively. The thickness and roughness of the resulting surfaces depend on the catalyst amount and the comonomer ratio, γ = [MAIGlc]0/[BIEM]0. A polymer brush of linear polyMAIGlc was also obtained in the presence of a sacrificial initiator via ATRP. Deprotection of the isopropylidene groups of the branched and linear polymer brushes resulted in hydrophilic surfaces as demonstrated by contact angle measurements. The quantitative deprotection was also confirmed by diffuse-reflectance infrared spectroscopy (DRIFT-IR). X-ray photoelectron spectroscopy (XPS) was further used to determine the surface chemical composition before and after deprotection.