title: Solid-state13C,15N and29Si NMR characterization of block copolymers with CO2capture properties.
abstract: Natural abundance solid-state multinuclear (13C,15N and29Si) cross-polarization magic-angle-spinning NMR was used to study structures of three block copolymers based on polyamide and dimethylsiloxane and two polyamides, one of which including ferrocene in its structure. Assignment of most of the resonance lines in13C,15N and29Si cross-polarization magic-angle-spinning NMR spectra were suggested. A comparative analysis of13C isotropic chemical shifts of polyamides with and without ferrocene has revealed a systematic shift towards higher δ -values (de-shielding) explained as the incorporation of paramagnetic ferrocene into the polyamide backbone. In addition, the13C NMR resonance lines for ferrocene-based polyamide were significantly broadened, because of paramagnetic effects from ferrocene incorporated in the structure of this polyamide polymer. Single resonance lines with chemical shifts ranging from 88.1 to 91.5 ppm were observed for15N sites in all of studied polyamide samples.29Si chemical shifts were found to be around -22.4 ppm in polydimethylsiloxane samples that falls in the range of chemical shifts for alkylsiloxane compounds. The CO2capture performance of polyamide-dimethylsiloxane-based block copolymers was measured as a function of temperature and pressure. The data revealed that these polymeric materials have potential to uptake CO2(up to 9.6 cm3g-1) at ambient pressures and in the temperature interval 30-40 °C. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Chemistry of Interfaces, Luleå University of Technology, SE-97187, Luleå, Sweden.
authors.forename: Faiz Ullah
authors.initials: FU
authors.lastname: Shah
authors.affiliation: Division of Material Science, Luleå University of Technology, SE-97187, Luleå, Sweden.
authors.forename: Farid
authors.initials: F
authors.lastname: Akhtar
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Muhammad Saif Ullah
authors.initials: MSU
authors.lastname: Khan
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Zareen
authors.initials: Z
authors.lastname: Akhter
authors.affiliation: Chemistry of Interfaces, Luleå University of Technology, SE-97187, Luleå, Sweden.
authors.forename: Oleg N
authors.initials: ON
authors.lastname: Antzutkin
keywords: CO2 capture; NMR characterization; block copolymers