Using natural cotton fibers to synthesize carbon nanotubes and electromagnetic wave absorption properties

Abstract In this paper, we report a new method for synthesizing carbon nanotubes (CNTs) and other carbon nanostructures such as carbon nanoparticles (CNPs) through catalytic thermolysis of natural cotton fibers. Using the new method, long CNTs (L-CNTs), which could reach to 20 μm or longer, can be readily synthesized from natural cotton fibers under hydrogen environment at a thermolysis temperature around 1200 °C. The analysis of the microstructure of synthesized L-CNTs showed that the CNT growth from the catalytic thermolysis of cotton fibers may not undergo a carbon-containing gas generation step that is different from most of other growth methods. We further studied the dielectric and electromagnetic wave (EMW) absorption properties of synthesized CNTs by embedding them in a epoxy matrix. The measurement results show that complex dielectric permittivity ɛ and EMW absorption ratio of the composites strongly depend on CNT loading in the frequency range from 8 to 26 GHz.