Investigation of the Thermal Behavior of Single-Walled Carbon Nanotubes and Tungsten Oxide Nanostructures Using Raman Spectroscopy

Thermal conductivity measurements of a variety of Single-Walled Carbon Nanotube (SWCNT) samples via Raman shifts of the G$^{\mathrm{+}}$ band frequency around 1592 cm$^{\mathrm{-1}}$ recorded with a 780 nm laser as a function of laser power (0 -- 25 mW) have allowed quantitative estimates of the purity levels of the SWCNTs. In addition, Raman spectra of a variety of tungsten oxide (WO$_{\mathrm{3}})$ nanomaterial samples, namely WO$_{\mathrm{3}}$ on silicon substrate, as well as nanopowder and nanowires, exhibited clear variation in O-H band features around 1550 cm$^{\mathrm{-1}}$ due to effects of ambient humidity, as well as other spectral features due to gas (NO$_{\mathrm{x}})$ exposure have been documented, as a function of varying temperature (in the range 27 -- 200\textdegree C). Thermal characteristics of SWCNTs and WO$_{\mathrm{3}}$ samples, along with the associated Molecular Dynamics simulations performed, will prove useful for thermal energy storage and gas sensing applications.