PMID- 15571398
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20050404
LR  - 20041201
IS  - 0002-7863 (Print)
IS  - 0002-7863 (Linking)
VI  - 126
IP  - 48
DP  - 2004 Dec 8
TI  - Assembly of well-aligned multiwalled carbon nanotubes in confined 
      polyacrylonitrile environments: electrospun composite nanofiber sheets.
PG  - 15754-61
AB  - Highly oriented, large area continuous composite nanofiber sheets made from 
      surface-oxidized multiwalled carbon nanotubes (MWNTs) and polyacrylonitrile (PAN) 
      were successfully developed using electrospinning. The preferred orientation of 
      surface-oxidized MWNTs along the fiber axis was determined with transmission 
      electron microscopy and electron diffraction. The surface morphology and height 
      profile of the composite nanofibers were also investigated using an atomic force 
      microscope in tapping mode. For the first time, it was observed that the 
      orientation of the carbon nanotubes within the nanofibers was much higher than 
      that of the PAN polymer crystal matrix as detected by two-dimensional wide-angle 
      X-ray diffraction experiments. This suggests that not only surface tension and 
      jet elongation but also the slow relaxation of the carbon nanotubes in the 
      nanofibers are determining factors in the orientation of carbon nanotubes. The 
      extensive fine absorption structure detected via UV/vis spectroscopy indicated 
      that charge-transfer complexes formed between the surface-oxidized nanotubes and 
      negatively charged (-CN[triple bond]N:) functional groups in PAN during 
      electrospinning, leading to a strong interfacial bonding between the nanotubes 
      and surrounding polymer chains. As a result of the highly anisotropic orientation 
      and the formation of complexes, the composite nanofiber sheets possessed enhanced 
      electrical conductivity, mechanical properties, thermal deformation temperature, 
      thermal stability, and dimensional stability. The electrical conductivity of the 
      PAN/MWNT composite nanofibers containing 20 wt % nanotubes was enhanced to 
      approximately 1 S/cm. The tensile modulus values of the compressed composite 
      nanofiber sheets were improved significantly to 10.9 and 14.5 GPa along the fiber 
      winding direction at the MWNT loading of 10 and 20 wt %, respectively. The 
      thermal deformation temperature increased with increased MWNT loading. The 
      thermal expansion coefficient of the composite nanofiber sheets was also reduced 
      by more than an order of magnitude to 13 x 10(-6)/ degrees C along the axis of 
      aligned nanofibers containing 20 wt % MWNTs.
FAU - Ge, Jason J
AU  - Ge JJ
AD  - Maurice Morton Institute and Department of Polymer Science, The University of 
      Akron, Akron, Ohio 44325, USA.
FAU - Hou, Haoqing
AU  - Hou H
FAU - Li, Qing
AU  - Li Q
FAU - Graham, Matthew J
AU  - Graham MJ
FAU - Greiner, Andreas
AU  - Greiner A
FAU - Reneker, Darrell H
AU  - Reneker DH
FAU - Harris, Frank W
AU  - Harris FW
FAU - Cheng, Stephen Z D
AU  - Cheng SZ
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
EDAT- 2004/12/02 09:00
MHDA- 2004/12/02 09:01
CRDT- 2004/12/02 09:00
PHST- 2004/12/02 09:00 [pubmed]
PHST- 2004/12/02 09:01 [medline]
PHST- 2004/12/02 09:00 [entrez]
AID - 10.1021/ja048648p [doi]
PST - ppublish
SO  - J Am Chem Soc. 2004 Dec 8;126(48):15754-61. doi: 10.1021/ja048648p.