Volume 10, No. 3, June 2010, Pages 212-218 PDF(386 KB)
Thermal Analysis of Multi-walled Carbon Nanotubes by Kissinger’s Corrected Kinetic Equation
Yu-Chen Hsieh1, Yu-Chuan Chou1, Chun-Ping Lin2, Tung-Feng Hsieh2,3, Chi-Min Shu1
1 Department of Safety, Health, and Environmental Engineering, National Yunlin University of Science and Technology (NYUST), 123,University Rd., Sec. 3, Douliou, Yunlin, Taiwan 64002, ROC
2 Graduate School of Engineering Science and Technology, NYUST, 123,University Rd., Sec. 3, Douliou, Yunlin, Taiwan 64002, ROC
3 Chienkuo Technology University of General Education Center, 1, Chieh Shou N. Rd., Changhua City, Taiwan 50094, ROC
Carbon nanotubes (CNTs) have been a popular material in recent years, but their thermal characteristics have not been understood completely. We investigated the unique thermal stability of multi-walled carbon nanotubes (MWCNTs) and used nitric acid (HNO3) to purify MWCNTs to promote its activation energy (Ea). The study used differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), and Fourier transform infrared (FTIR) spectrometer to analyze as-grown MWCNTs and modified MWCNTs. For DSC, the heating rate was chosen to be 0.25 to 2.0 °C/min. From DSC results, Ea and exothermic onset temperature (T0) of the modified MWCNTs increased with increasing HNO3 concentration. The TGA results showed that both as-grown and modified MWCNTs’ decomposition temperatures were higher than 500°C in air. The infrared spectra of as-grown MWCNTs and modified MWCNTs have shown that the gas phase composition is CO2 after TGA linked with FTIR. By Kissinger’s corrected kinetic equation, Ea increased with increasing HNO3 concentration. Through this study, we realized that as-grown MWCNTs and modified MWCNTs are thermally hazardous materials with high potential heat of decomposition, especially under fire exposure. Thus, it is important to know the thermal hazard characteristics of material with a measure to prevent its thermal damage during perturbed situations.
Multi-walled carbon nanotubes (MWCNTs); Nitric acid (HNO3); Activation energy (Ea); Differential scanning calorimetry (DSC); Kissinger’s corrected kinetic equation.