title: Precision synthesis of poly(ionic liquid)-based block copolymers by cobalt-mediated radical polymerization and preliminary study of their self-assembling properties.
abstract: A poly(ionic liquid)-based block copolymer (PIL BCP), namely, poly(vinyl acetate)-b-poly(N-vinyl-3-butylimidazolium bromide), PVAc-b-PVBuImBr, is synthesized by sequential cobalt-mediated radical polymerization (CMRP). A PVAc precursor is first prepared at 30 °C in bulk by CMRP of VAc, using bis(acetylacetonato)cobalt(II), Co(acac)2, and a radical source (V-70). Growth of PVBuImBr from PVAc-Co(acac)2 is accomplished by CMRP in DMF/MeOH (2:1, v/v). This PIL BCP self-assembles in the sub-micron size range into aggregated core-shell micelles in THF, whereas polymeric vesicles are observed in water, as evidenced by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Thin-solid sample cut from raw materials analyzed by TEM shows an ordered lamellar organization by temperature-dependent synchrotron small-angle X-ray scattering (SAXS). Anion exchange can be accomplished to achieve the corresponding PIL BCP with bis(trifluorosulfonyl)imide (Tf2 N(-)) anions, which also gives rise to an ordered lamellar phase in bulk samples. A complete suppression of SAXS second-order reflection suggests that this compound has a symmetric volume fraction (f ≈ 0.5). SAXS characterization of both di- and triblock PIL BCP analogues previously reported also shows a lamellar phase of very similar behavior, with only an increase of the period by about 8% at 60 °C.
authors: Université de Bordeaux, Laboratoire de Chimie des Polymères Organiques, IPB-ENSCBP, F-33607, Pessac cedex, France; Centre National de la Recherche Scientifique, Laboratoire de Chimie des Polymères Organiques, 16 avenue Pey-Berland, F-33607, Pessac cedex, France; POLYMAT Institute for Polymer Materials, University of the Basque Country UPV/EHU, Joxe Mari Korta Center, Avda. Tolosa 72, 20018, Donostia-san Sebastian, Spain.
authors: Paul
authors: P
authors: Coupillaud
authors: Maréva
authors: M
authors: Fèvre
authors: Anne-Laure
authors: AL
authors: Wirotius
authors: Karim
authors: K
authors: Aissou
authors: Guillaume
authors: G
authors: Fleury
authors: Antoine
authors: A
authors: Debuigne
authors: Christophe
authors: C
authors: Detrembleur
authors: David
authors: D
authors: Mecerreyes
authors: Joan
authors: J
authors: Vignolle
authors: Daniel
authors: D
authors: Taton
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008823:Micelles; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D005609:Free Radicals; D052578:Ionic Liquids; D008823:Micelles; D011108:Polymers; D014867:Water; D003035:Cobalt
keywords: CMRP; block copolymer; mesostructure; poly(ionic liquid); self-assembly