Preparation and Electromagnetic Properties of Carbon Nanofiber/Epoxy Composites

Carbon nanofibers (CNFs) with diameters ranging from 50 nm to 150 nm were prepared from polymer blends of polyacrylonitrile (PAN)/polymethyl methacrylate (PMMA) via a wet-spinning method and subsequent thermal treatment. The main factors that influence the diameter of the CNFs, including molecular weight of PAN, mass ratio of PAN/PMMA, and spinning draw ratio, are discussed. The formation of graphitization structures of the blend fibers during the carbonization process was investigated by Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction spectroscopy. The complex permittivity ϵ (ϵ′ − jϵ″), complex permeability μ (μ′ − jμ″), and microwave absorption properties of CNF/epoxy composites were studied in the X-band frequency range (8.2–12.4 GHz). ϵ′, ϵ″, μ′, and μ″’ were found to increase with increased CNF content. Measured values of these parameters were used to determine the reflection loss at various sample thicknesses, based on a model of a single-layered plane wave absorber backed by a perfect conductor. The calculated results showed that the composite with a CNF content of 8 wt% and a thickness of 2.1 mm would give a maximum reflection loss of −34 dB at 10.5 GHz with the −10 dB bandwidth over the extended frequency range of 8.8–12.4 GHz.

[1]  Y. Kim,et al.  Synthesis and characterization of porous carbon nanofibers with hollow cores through the thermal treatment of electrospun copolymeric nanofiber webs. , 2007, Small.

[2]  C. V. Gulijk,et al.  Characterizing herring bone structures in carbon nanofibers using selected area electron diffraction and dark field transmission electron microscopy , 2006 .

[3]  Tianbao Li,et al.  Preparation of vapor-grown carbon fibers from deoiled asphalt , 2006 .

[4]  A. Ōya,et al.  Preparation of highly crystalline carbon nanofibers from pitch/polymer blend , 2006 .

[5]  Zhi‐Kang Xu,et al.  Preparation and properties of the polyimide/multi-walled carbon nanotubes (MWNTs) nanocomposites , 2006 .

[6]  W. Yuan,et al.  Modeling of fishbone-type carbon nanofibers : A theoretical study , 2005 .

[7]  Seongyop Lim,et al.  Surface Modification of Carbon Nanofiber with High Degree of Graphitization , 2004 .

[8]  A. Tanaka,et al.  Preparation of highly crystalline nanofibers on Fe and Fe–Ni catalysts with a variety of graphene plane alignments , 2004 .

[9]  K. P. Jong,et al.  The influence of oxidation on the texture and the number of oxygen-containing surface groups of carbon nanofibers , 2004 .

[10]  A. Ōya,et al.  The polymer blend technique as a method for designing fine carbon materials , 2003 .

[11]  Young-Seak Lee,et al.  Surface characteristics of fluorine-modified PAN-based carbon fibers , 2003 .

[12]  C. Boothroyd,et al.  Synthesis and Characterization of Carbon Nanofibers Produced by the Floating Catalyst Method , 2002 .

[13]  B. Rand,et al.  Structural analysis of carbon nanofibres grown by the floating catalyst method , 2002 .

[14]  A. Ōya,et al.  Carbon Nanotubes Prepared by Spinning and Carbonizing Fine Core–Shell Polymer Microspheres , 2002 .

[15]  N. Patel,et al.  Designing carbon materials with unique shapes using polymer blending and coating techniques , 2002 .

[16]  J. Hwang,et al.  Synthesis and hydrogen storage of carbon nanofibers , 2002 .

[17]  A. Ōya,et al.  Carbon nanotubes prepared from polymer microspheres by spinning and carbonizing , 2002 .

[18]  K. Okabe,et al.  An attempt to prepare carbon nanotubes by the spinning of microcapsules , 2001 .

[19]  A. Ōya,et al.  Preferential supporting of platinum particles on pore surface using a polymer blend technique , 2001 .

[20]  N. Kasahara,et al.  Preparation of thin carbon fibers from phenol–formaldehyde polymer micro-beads dispersed in polyethylene matrix , 2000 .

[21]  A. Ōya,et al.  Preparation of platinum loaded carbon fiber by using a polymer blend , 1997 .

[22]  A. Ōya,et al.  Novel preparation method for the production of mesoporous carbon fiber from a polymer blend , 1997 .