Studies on graphitic carbon nanofibers: towards electronic, mechanical and biological applications
Li, Jiang
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2006-07-13
Abstract
Graphitic carbon nanofibers (GCNFs) have become the subject of extensive research due to their high aspect ratio, large surface area, superior electronic and mechanical properties. A variety of nanocomposites containing GCNFs have been designed, synthesized and characterized in this study. Surface-reactive carbon atoms have enabled the surface functionalization of herringbone GCNFs with covalently bound linker molecules, including diamines, triamines and an aminoalkoxysilane. GCNF/epoxy nanocomposites have been fabricated using GCNFs surface-derivatized with diamine linker molecules, and bending test data have revealed enhanced flexural strength for these nanocomposites over pure epoxy specimens. In addition, GCNF/silica xerogel nanocomposites prepared via sol-gel chemistry of GCNF/amidoalkoxysilane have displayed improved wetting and dispersion of GCNFs within a ceramic matrix. Further, attempts to bind antibodies and radionuclides onto surface-functionalized GCNFs have demonstrated interesting results for potential biological applications. Moreover, GCNFs have been grown on diverse substrates, including silicon wafers, carbon felt and carbon paper. Work functions of GCNFs have been acquired from thermionic electron emission measurements. GCNF/SiC/carbon felt nanocomposites prepared by carbothermal reduction exhibit optimized mechanical robustness, high chemical stability and reversible superhydrophobicity, and serve as a close structural mimic of a lotus leaf. Furthermore, the electrical resistance of GCNF/carbon paper nanocomposites has been evaluated for potential use as gas diffusion layers in fuel cells.