Graphene Wool Air Pollutant Samplers
Air quality is a concern worldwide. Consequently, efficient means to monitor air pollutants are critical. Current commercially available carbon-based sorbents used for sampling volatile organic compounds (VOCs) in air typically require solvent extraction prior to analysis and they cannot be re-used. The graphene wool (GW) trap samplers which we have developed can be thermally desorbed (which does not use solvents and is thus more environmentally friendly and cost-effective) and importantly they can be conditioned and re-used. The low back pressure of the GW sampler also enables the use of a small portable battery-operated personal sampling pump, which will enhance the market uptake and usability of our product, which can be used in different sampler formats.
Quartz wool was used for the first time as a substrate for the synthesis of graphene by chemical vapour deposition whereby the process was optimised and the graphene was characterised by Raman spectroscopy. For application as a sorbent for volatile organic compounds (VOe) air pollutants, the graphene wool is inserted into a glass liner to either be used as a stand-alone trap or as a sandwich trap in conjunction with other sorbents (such as polydimethylsiloxane) in a denuder sampling device setup, for example. The specifications and assembly of the trap have been optimised and the collection efficiencies were shown to be over 90 % for octane, dodecane, and hexadecane gases and the re-use of the trap has also been demonstrated.