title: Thermally Induced Charge Reversal of Layer-by-Layer Assembled Single-Component Polymer Films.
abstract: Temperature can be harnessed to engineer unique properties for materials useful in various contexts and has been shown to affect the layer-by-layer (LbL) assembly of polymer thin films and cause physical changes in preassembled polymer thin films. Herein we demonstrate that exposure to relatively low temperatures (≤ 100 °C) can induce physicochemical changes in cationic polymer thin films. The surface charge of polymer films containing primary and secondary amines reverses after heating (from positive to negative), and different characterization techniques are used to show that the change in surface charge is related to oxidation of the polymer that specifically occurs in the thin film state. This charge reversal allows for single-polymer LbL assembly to be performed with poly(allylamine) hydrochloride (PAH) through alternating heat/deposition steps. Furthermore, the negative charge induced by heating reduces the fouling and cell-association of PAH-coated planar and particulate substrates, respectively. This study highlights a unique property of thin films which is relevant to LbL assembly and biofouling and is of interest for the future development of thin polymer films for biomedical systems.
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Richardson
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Blaise L
authors.initials: BL
authors.lastname: Tardy
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ejima
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Junling
authors.initials: J
authors.lastname: Guo
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Cui
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Kang
authors.initials: K
authors.lastname: Liang
authors.affiliation: School of Chemical Engineering and SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University , Suwon, 16419, South Korea.
authors.forename: Gwan H
authors.initials: GH
authors.lastname: Choi
authors.affiliation: School of Chemical Engineering and SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University , Suwon, 16419, South Korea.
authors.forename: Pil J
authors.initials: PJ
authors.lastname: Yoo
authors.affiliation: Department of Pharmaceutics, Ghent University , Ghent, Belgium.
authors.forename: Bruno G
authors.initials: BG
authors.lastname: De Geest
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D002460:Cell Line; D006801:Humans; D008567:Membranes, Artificial; D011073:Polyamines / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D011073:Polyamines; C063994:polyallylamine
keywords: cell adhesion; charge conversion; layer-by-layer assembly; low-fouling; single-polymer