dc.contributor.author |
Geldenhuys, Genna-Leigh
|
|
dc.contributor.author |
Mason, Yvonne C.
|
|
dc.contributor.author |
Dragan, George C.
|
|
dc.contributor.author |
Zimmermann, Ralf
|
|
dc.contributor.author |
Forbes, Patricia B.C.
|
|
dc.date.accessioned |
2022-07-11T10:48:35Z |
|
dc.date.available |
2022-07-11T10:48:35Z |
|
dc.date.issued |
2021-09-13 |
|
dc.description.abstract |
Volatile and semivolatile organic compounds in
ambient air and occupational settings are of great concern due to
their associated adverse human health and environmental impacts.
Novel graphene wool samplers have been developed and tested to
overcome limitations of commercially available sorbents that can
only be used once and typically require solvent extraction.
Graphene wool (GW) was synthesized by non-catalytic chemical
vapor deposition with optimized conditions, resulting in a novel
fibrous graphene wool that is very easy to manage and less rigid
than other forms of graphene, lending itself to a wide range of
potential applications. Here, the air pollutant sampling capabilities of the GW were of interest. The optimal packing weight of GW
inside a glass tube (length 178 mm, i.d. 4 mm, o.d. 6 mm) was investigated by the adsorption of vaporized alkane standards on the
GW, using a condensation aerosol generator in a temperature-controlled chamber and subsequent detection using a flame ionization
detector. The optimized GW packing density was found to be 0.19 mg mm−3 at a flow rate of 500 mL min−1, which provided a gas
collection efficiency of >90% for octane, decane, and hexadecane. The humidity uptake of the sampler is less than 1% (m/m) for
ambient humidities <70%. Breakthrough studies showed the favorable adsorption of polar molecules, which is attributed to the
defective nature of the graphene and the inhomogeneous coating of the graphene layers on the quartz wool, suggesting that the polar
versus non-polar uptake potential of the GW can be tuned by varying the graphene layering on the quartz wool substrate during
synthesis. Oxidized domains at the irregular edges of the graphene layers, due to a broken, non-pristine sp2 carbon network, allow for
adsorption of polar molecules. The GW was applied and used in a combustion sampling campaign where the samplers proved to be
comparable to frequently used polydimethylsiloxane sorbents in terms of sampling and thermal desorption of non-polar semivolatile
organic compounds. The total alkane concentrations detected after thermal desorption of GW and PDMS samplers were found to be
17.96 ± 13.27 and 18.30 ± 16.42 μg m−3, respectively; thus, the difference in the alkane sampling concentration between the two
sorbent systems was negligible. GW provides a new, exciting possibility for the monitoring of organic air pollutants with numerous
advantages, including high sampling efficiencies, simple and cost-effective synthesis of the thermally stable GW, solvent-free and
environmentally friendly analysis, and, importantly, the reusability of samplers. |
en_US |
dc.description.department |
Chemistry |
en_US |
dc.description.librarian |
am2022 |
en_US |
dc.description.sponsorship |
The National Research Foundation (NRF) and the Departments of Chemistry and Physics at the University of Pretoria and Impala Platinum Ltd. |
en_US |
dc.description.uri |
http://pubs.acs.org/journal/acsodf |
en_US |
dc.identifier.citation |
Geldenhuys, G.-L., Mason, Y., Dragan, G.C. et al. Novel graphene wool gas adsorbent for volatile and semivolatile organic compounds. ACS Omega 2021, 6, 24765−24776. |
en_US |
dc.identifier.issn |
2470-1343 (online) |
|
dc.identifier.other |
10.1021/acsomega.1c03595 |
|
dc.identifier.uri |
https://repository.up.ac.za/handle/2263/86087 |
|
dc.language.iso |
en |
en_US |
dc.publisher |
American Chemical Society |
en_US |
dc.rights |
© 2021 The Authors. Published by American Chemical Society. This is an open access article published under an ACS AuthorChoice License. |
en_US |
dc.subject |
Volatile |
en_US |
dc.subject |
Semivolatile organic compounds |
en_US |
dc.subject |
Ambient air |
en_US |
dc.subject |
Human health |
en_US |
dc.title |
Novel graphene wool gas adsorbent for volatile and semivolatile organic compounds |
en_US |
dc.type |
Article |
en_US |