Nanoporous ultrahigh specific surface polyacrylonitrile fibres Lifeng, Zhang; Hsieh, Y-L [Fiber and Polymer Science, University of California, Davis, CA 95616 (United States)] 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CALORIMETRY; CYCLIZATION; DISSOLUTION; ETHYLENE; FOURIER TRANSFORMATION; INFRARED SPECTRA; MELTING; NITRILES; NMR IMAGING; NUCLEAR MAGNETIC RESONANCE; ORGANIC POLYMERS; OXIDES; PRECURSOR; SPECTROSCOPY; SURFACES; WATER; X-RAY DIFFRACTION The concept of phase separation was coupled with electrospinning to generate polyacrylonitrile (PAN) and poly(ethylene oxide) (PEO) bicomponent fibres that, upon removal of the phase-separated PEO domains, became nanoporous. Electrospinning of PAN (150 kDa) with 15-50% w/w PEO (10 kDa) at a 8% w/w total concentration in N,N-dimethylformamide produced fibres with decreasing averaged diameters from 390 to 130 nm. Evidence of phase separation between PAN and PEO in the bicomponent fibres was indicated by the characteristic PAN and PEO peaks by Fourier transform infrared (FTIR) spectroscopy and solid-state nuclear magnetic resonance (NMR) imaging, and confirmed by the co-existence of PAN cyclization and PEO melting by differential scanning calorimetry (DSC) and the presence of PEO crystalline diffraction by wide-angle x-ray scattering (WAXS). Removal of PEO by dissolution in water was confirmed by the matched mass loss to PEO fraction and the absence of PEO by FTIR and DSC. The water-treated bicomponent fibres appeared slightly larger in diameter and contained internal pores of nanometre scale. The nanoporous fibres generated from 50/50 PAN/PEO bicomponent precursor contained internal pores of a few nanometres to tens of nanometres in size and had 50% higher pore volume and 2.5-fold higher specific surface. Available online at http://stacks.iop.org/0957-4484/17/4416/nano6_17_022.pdf or at the Web site for the journal Nanotechnology (Print) (ISSN 1361-6528 ) http://www.iop.org/;INIS United Kingdom 2006-09-14 English Journal Article Journal Name: Nanotechnology (Print); Journal Volume: 17; Journal Issue: 17; Other Information: PII: S0957-4484(06)25336-4; DOI: 10.1088/0957-4484/17/17/022; Country of input: International Atomic Energy Agency (IAEA) Medium: X; Size: page(s) 4416-4423 https://doi.org/10.1088/0957-4484/17/17/022; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA) [] 17 17 Journal ID: ISSN 0957-4484; TRN: GB06P8217006882 GBN 2010-12-31 20832484