FTIR Determination of Surfactant Removal from Arc Discharge Buckypapers for Air Sampling

In our previous work, buckypapers (BPs) were fabricated for use as sorbents for the air sampling of vapors. The fabrication methods used suspended arc discharge (AD) single-walled carbon nanotubes (SWNTs) in a surfactant and water solution, then subsequently vacuum filtered the suspension to remove the supernatant. The BPs were then heat-treated to remove any residual surfactants remaining from fabrication, which was corroborated by gravimetric and surface analysis. The present work sought to validate these findings using Fourier-transform infrared spectrometry (FTIR) analysis of heat treated (HT) and non-heat treated (NHT) BPs. The effect of humidity on FTIR spectra was also considered to determine proper storage of BPs. This was assessed by storing BPs in three different environments over the course of four weeks and performing FTIR analyses weekly to determine changes due to humidity. The findings of FTIR analyses appear to indicate surfactants were removed in the heat treatment process, though water interference in the spectral data prevents conclusive evidence. It was also concluded that storing BPs in an airtight container of desiccant, under a dry nitrogen gas was the best way to prevent water retention overtime.