title: Ionization of covalent immobilized poly(4-vinylphenol) monolayers measured by ellipsometry, QCM and SPR.
abstract: Covalently immobilized poly(4-vinylphenol) (PVP) monolayer films were fabricated by spin coating PVP on perfluorophenyl azide (PFPA)-functionalized surface followed by UV irradiation. The pH-responsive behavior of these PVP ultrathin films was evaluated by ellipsometry, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). By monitoring the responses of these films to pHin situ, the ionization constant of the monolayer thin films was obtained. The apparent pKavalue of these covalently immobilized PVP monolayers, 13.4 by SPR, was 3 units higher than that of the free polymer in aqueous solution.
authors.affiliation: Department of Chemistry, University of Massachusetts Lowell, 1 University Ave., Lowell, MA 01854, United States.
authors.forename: Suji
authors.initials: S
authors.lastname: Uppalapati
authors.affiliation: KTH-Royal Institute of Technology, Department of Chemistry, Teknikringen 30, S-10044 Stockholm, Sweden.
authors.forename: Na
authors.initials: N
authors.lastname: Kong
authors.affiliation: KTH-Royal Institute of Technology, Department of Chemistry, Teknikringen 30, S-10044 Stockholm, Sweden.
authors.forename: Oscar
authors.initials: O
authors.lastname: Norberg
authors.affiliation: KTH-Royal Institute of Technology, Department of Chemistry, Teknikringen 30, S-10044 Stockholm, Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Ramström
authors.affiliation: Department of Chemistry, University of Massachusetts Lowell, 1 University Ave., Lowell, MA 01854, United States ; KTH-Royal Institute of Technology, Department of Chemistry, Teknikringen 30, S-10044 Stockholm, Sweden.
authors.forename: Mingdi
authors.initials: M
authors.lastname: Yan
keywords: Ionization constant; Monolayer; Perfluorophenyl azide; Poly(4-vinylphenol); pH response