title: Photoelectron spectroscopy studies of the functionalization of a silicon surface with a phosphorylcholine-terminated polymer grafted onto (3-aminopropyl)trimethoxysilane.
abstract: The structure of a biomimetic phosphorylcholine (PC)-functionalized poly(trimethylene carbonate) (PC-PTMC-PC), linked to a silicon substrate through an aminolysis reaction at 120 degrees C with (3-aminopropyl)trimethoxysilane (APTMS), was studied using photoelectron spectroscopy. Two chemical states were found for the unreacted APTMS amine, a neutral state and a protonated state, where the protonated amine on average was situated closer to the silicon substrate than the neutral amine. The experiments also indicated the presence of a third chemical state, where amines interact with unreacted silanol groups. The PTMC chains of the grafted films were found to consist of only 2-3 repeat units, with the grafted chains enriched in the zwitterionic end group, suggesting that these groups are attracted to the surface. This was further supported by the experiments showing that the PC groups were situated deeper within the film.
authors.affiliation: Department of Physics, Box 530, and Department of Materials Chemistry, Polymer Chemistry, Box 538, Uppsala University, SE-751 21 Uppsala, Sweden. emma.kristensen@fysik.uu.se
authors.forename: Emma M E
authors.initials: EM
authors.lastname: Kristensen
authors.forename: Fredrik
authors.initials: F
authors.lastname: Nederberg
authors.forename: Håkan
authors.initials: H
authors.lastname: Rensmo
authors.forename: Tim
authors.initials: T
authors.lastname: Bowden
authors.forename: Jöns
authors.initials: J
authors.lastname: Hilborn
authors.forename: Hans
authors.initials: H
authors.lastname: Siegbahn
mesh_terms: D004583:Electrons; D007700:Kinetics; D015394:Molecular Structure; D010767:Phosphorylcholine / Q000737:chemistry*; D010777:Photochemistry; D011108:Polymers / Q000737:chemistry*; D011437:Propylamines / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D011108:Polymers; D011437:Propylamines; D012821:Silanes; D010767:Phosphorylcholine; C088294:3-aminopropyltrimethoxysilane; D012825:Silicon