Carbon Nanotube Composite Curing Through Absorption Of Microwave Radiation

The microwave absorbing properties and subsequent heating of carbon nanotubes can be used to rapidly cure ceramic composites. With less than 1 wt% carbon nanotube additives and 30-40 W of directed microwave power (2.45 GHz), bulk composite samples reach temperatures above 500 degrees C within 1 min. Multiwalled carbon nanotubes (MWNTs), functionalized MWNTs (f-MWNTs), raw single-walled carbon nanotubes (r-SWNTs) and purified SWNTs (p-SWNTs) were all used to produce composites in Starfire (R) SMP-10 silicon carbide pre-ceramic. MWNTs loaded at 0.75 wt% in SMP-10 consistently displayed the fastest rate of heating (similar to 500 degrees C in 10 s) and highest temperatures (1150 degrees C in 7 min). The degree of composite curing was monitored by TGA. The nanotube/matrix dispersion and integrity was imaged using optical microscopy, TEM and SEM, and Raman spectroscopy was used to determine the state of the nanotubes after exposure to microwave radiation. (c) 2008 Elsevier Ltd. All rights reserved.