Title: | Photothermal Desorption of Toluene from Carbonaceous Substrates Using Light Flash |
Author(s): | Floyd EL; Oh J; Sapag K; Oni TM; Shedd JS; Lungu CT; |
Address: | "Department of Environmental Health Sciences, The University of Alabama at Birmingham, Birmingham, AL 35294, USA. Department of Occupational and Environmental Health, University of Oklahoma Health Sciences Center, Oklahoma, OK 73126, USA. Department of Physics, National University of San Luis, San Luis D5700HHW, Argentina" |
ISSN/ISBN: | 2079-4991 (Print) 2079-4991 (Electronic) 2079-4991 (Linking) |
Abstract: | "Millions of workers are occupationally exposed to volatile organic compounds (VOCs) annually. Current exposure assessment techniques primarily utilize sorbent based preconcentrators to collect VOCs, with analysis performed using chemical or thermal desorption. Chemical desorption typically analyzes 1 microL out of a 1 mL (0.1%) extraction volume providing limited sensitivity. Thermal desorption typically analyzes 100% of the sample which provides maximal sensitivity, but does not allow repeat analysis of the sample and often has greater sensitivity than is needed. In this study we describe a novel photothermal desorption (PTD) technique to bridge the sensitivity gap between chemical desorption and thermal desorption. We used PTD to partially desorb toluene from three carbonaceous substrates; activated carbon powder (AC-p), single-walled carbon nanotube (SWNT) powder (SWNT-p) and SWNT felts (SWNT-f). Sorbents were loaded with 435 ug toluene vapour and irradiated at four light energies. Desorption ranged from <0.007% to 0.86% with a single flash depending on substrate and flash energy. PTD was significantly greater and more consistent in SWNT-f substrates compared to AC-p or SWNT-p at all irradiation energies. We attribute the better performance of SWNT-f to greater utilization of its unique nanomaterials properties: high thermal conductivity along the nanotube axis, and greater interconnection within the felt matrix compared to the powdered form" |
Keywords: | carbon nanotubes carbonaceous substrates photothermal desorption thermal desorption toluene; |
Notes: | "PubMed-not-MEDLINEFloyd, Evan L Oh, Jonghwa Sapag, Karim Oni, Toluwanimi M Shedd, Jacob S Lungu, Claudiu T eng P42 ES027723/ES/NIEHS NIH HHS/ T42 OH008436/OH/NIOSH CDC HHS/ 5T42OH008436-15/OH/NIOSH CDC HHS/ 1R21OH010373/OH/NIOSH CDC HHS/ Switzerland 2022/02/27 Nanomaterials (Basel). 2022 Feb 16; 12(4):662. doi: 10.3390/nano12040662" |