A novel desorption technique for improved sensitivity in sampling for gases

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DESCRIPTION (provided by applicant): Granular Activated Carbon (GAC) is the gold standard for volatile organic compound (VOC) sampling, but recently other carbonaceous porous materials like Single Walled Carbon Nanotubes (SWNT) and Porous Graphitized Carbon Particles (HDCP) have shown comparable adsorption and desorption attributes. Recent studies showed that SWNT efficiently absorb visible light and transform it in heat, hinting that irradiatio of samples loaded with vapors through air sampling could be desorbed by light irradiation. This will significantly simplify the current analytical methods and will increase sensitivity of analysi. We propose to fabricate five different matrix substrates based on SWNT, HDCP and GAC, characterize their physical and adsorption properties and determine the temperature response when irradiated with various energies and frequencies of pulsed, intense visible light. We will use the irradiation scenario that yields the highest temperature increase, load the substrates with toluene vapors and determine the amount of desorbed toluene for each irradiation/substrate/loading combination. If successful this project could open the door for extensive research that will investigate the best parameters needed to build new air samplers based on this new photo-desorption principle.