Dynamic Nitroxide Functional Materials. Issue 71 (16th November 2018)

• Record Type: Journal Article
• Authors: Woehlk, Hendrik; Lauer, Andrea; Trouillet, Vanessa; Welle, Alexander; Barner, Leonie; Blinco, James P.; Fairfull‐Smith, Kathryn E.; Barner‐Kowollik, Christopher
• Is Part Of: Chemistry. Volume 24:Issue 71(2018)
• Page Start: 18873
• Page End: 18879
• Publication Date: 2018-11-16
• Subjects: dynamic covalent chemistry -- nitroxide radicals -- photochemistry -- polydopamine coating -- surface functionalization; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201804602
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A substrate‐independent and versatile coating platform for (spatially resolved) surface functionalization, based on nitroxide radical coupling (NRC) reactions and the formation of thermo‐labile alkoxyamine functional groups, was introduced. Nitroxide‐decorated poly(glycidyl methacrylate) (PGMA) microspheres, obtained through bioinspired copolymer surface deposition using dopamine and a nitroxide functional dopamine derivative as monomers, were conjugated with small functional groups in a rewritable process. Reversible coding of the nitroxide functional microspheres by NRC and decoding through thermal alkoxyamine fission were monitored and characterized by electron paramagnetic resonance (EPR) spectroscopy and X‐ray photoelectron spectroscopy (XPS). In addition, this nitroxide coating system was exploited in "grafting‐to" polymer surface ligations of poly(methyl methacrylate) (PMMA) and poly(2, 2, 2‐trifluoroethyl methacrylate) (PTFEMA) in spatially confined areas. Polymer strands terminated with an Irgacure 2959 (2‐hydroxy‐4′‐(2‐hydroxyethoxy)‐2‐methylpropiophenone) photoinitiator were obtained through chain‐transfer polymerization, and subsequently coupled to nitroxide‐immobilized poly(dopamine) (PDA)‐coated silicon substrates by using rapid photoclick NRC reactions. Light‐driven polymer surface coding was visualized by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) and XPS imaging. Abstract : Coating with nitroxide : A versatile, bioinspired nitroxide functional coating platform is presented for precise programming of various materials. Nitroxide‐coated polymeric microspheres with rewritable properties were manufactured, exemplified in consecutive nitroxide radical coupling (coding) and thermal alkoxyamine fission (decoding) reaction steps. Photoinduced dual‐polymer‐patterned surfaces were further generated highlighting the broad applicability of our nitroxide coating system.