title: Controlled grafting of well-defined epoxide polymers on hydrogen-terminated silicon substrates by surface-initiated ATRP at ambient temperature.
abstract: Controlled grafting of well-defined epoxide polymer brushes on the hydrogen-terminated Si(100) substrates (Si-H substrates) was carried out via the surface-initiated atom-transfer radical polymerization (ATRP) at room temperature. Thus, glycidyl methacrylate (GMA) polymer brushes were prepared by ATRP from the alpha-bromoester functionalized Si-H surface. Kinetic studies revealed a linear increase in GMA polymer (PGMA) film thickness with reaction time, indicating that chain growth from the surface was a controlled "living" process. The graft polymerization proceeded more rapidly in the dimethylformamide/water (DMF/H(2)O) mixed solvent medium than in DMF, leading to much thicker PGMA growth on the silicon surface in the former medium. The chemical composition of the GMA graft-polymerized silicon (Si-g-PGMA) surfaces were characterized by X-ray photoelectron spectroscopy (XPS). The fact that the epoxide functional groups of the grafted PGMA were preserved quantitatively was revealed in the reaction with ethylenediamine. The "living" character of the PGMA chain end was further ascertained by the subsequent growth of a poly(pentafluorostyrene) (PFS) block from the Si-g-PGMA surface, using the PGMA brushes as the macroinitiators.
authors.affiliation: Department of Chemical Engineering, National University of Singapore, Kent Ridge, Singapore.
authors.forename: W H
authors.initials: WH
authors.lastname: Yu
authors.forename: E T
authors.initials: ET
authors.lastname: Kang
authors.forename: K G
authors.initials: KG
authors.lastname: Neoh
mesh_terms: D004852:Epoxy Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D008689:Methacrylates / Q000138:chemical synthesis* / Q000737:chemistry; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D004852:Epoxy Compounds; D008689:Methacrylates; D011108:Polymers; D011137:Polystyrenes; D006859:Hydrogen; C007870:glycidyl methacrylate; D012825:Silicon