Samantha L CONNELL, Evan L FLOYD and Claudiu T LUNGU; Evaluation of Carbon Nanotube Buckypaper as a Sorbent for Passive Sampling of Toluene; Advanced Materials and Technologies Environmental Sciences; 2017:1(3):118-125


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Passive air sampling is a preferred method of air sampling for many applications. Traditionally, this method uses activated carbon as the sorbent and samples are analyzed by chemical or thermal desorption. This research explores the use of carbon nanotubes in the form of a buckypaper as a sorbent for passive sampling by comparing the mass uptake and percent yield to that of the 3M™ Organic Vapor Monitor 3500 over four time trials (30, 60, 120 and 240min) using toluene as the sorbate. A total of 48 samples were taken and results were analyzed using a gas chromatograph. The desorption efficiency and mass uptake rate of the carbon nanotube sorbents were similar to the 3M™ Organic Vapor Monitor 3500. Desorption efficiencies were 85.5 – 100.3% for 3M samplers and 89.5 – 95.5% for carbon nanotube sorbents. The mass of toluene collected at 30-minute and 120-minute time trials showed no significant differences (p = 0.37, 0.1, respectively) while 60min and 240min time trials were significantly different with fabricated sorbents collecting closer to the expected mass (p = 0.02, 0.04 respectively). Overall sampling capacity is lower in the 20mg carbon nanotube buckypapers compared to the 200mg activated carbon pad of the 3M™ OVM 3500 due to somewhat lower adsorption capacity and much lower sorbent mass. While the objective of this study was to explore the suitability of buckypaper sorbents for sampling exposures at low concentration for short durations, a larger mass buckypaper sorbent should provide a similar sampling capacity to standard passive samplers.