Publication Type Journal Article
Title Volatile Organic Compound Monitoring during Extreme Wildfires: Assessing the Potential of Sensors Based on LbL and Sputtering Films
Authors Catia Magro O. C. Gonçalves Marcelo Morais Paulo A. Ribeiro S. Serio Pedro Vieira Maria Raposo
Groups Chem4Env
Journal SENSORS
Year 2022
Month
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Volume 22
Number 17
Pages
Abstract A new theory suggests that flammable gases generated by heated vegetation, in particular the volatile organic compounds (VOC) common to Mediterranean plants, may, under certain topographic and wind conditions, accumulate in locations where, after the arrival of the ignition source, they rapidly burst into flames as explosions. Hence, there is a need for the development of a system that can monitor the development of these compounds. In this work, a sensor s array is proposed as a method for monitoring the amount of eucalyptol and alpha-pinene, the major VOC compounds of the Eucalyptus and Pine trees. The detection of the target compounds was assessed using the impedance spectroscopy response of thin films. Combinations of layers of polyelectrolytes, such as poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), poly(sodium 4-sytrenesulfonate) (PSS) graphene oxide (GO), and non/functionalized multiwall nanotubes (MWCNT-COOH or MWCNT), namely, PAH/GO, PEI/PSS, PEI/GO, PAH/MWCNT, PAH/MWCNT-COOH, films, and TiO2 and ZnO sputtered films, were deposited onto ceramic supports coated with gold interdigitated electrodes. The results showed that concentrations of the target VOCs, within the range of 68 to 999 ppm(v), can be easily distinguished by analyzing the impedance spectra, particularly in the case of the ZnO- and PAH/GO-film-based sensors, which showed the best results in the detection of the target compounds. Through principal component analysis (PCA), the best set of features attained for the ZnO and PAH/GO based sensor devices revealed a linear trend of the PCA s first principal component with the concentration within the range 109 and 807 ppm(v). Thus, the values of sensitivity to eucalyptol and alpha-pinene concentrations, which were (2.2 +/- 0.3) x 10(-4) and (5.0 +/- 0.7) x 10(-5) per decade, respectively, as well as resolutions of 118 and 136 ppb(v), respectively, were identified.
DOI http://dx.doi.org/10.3390/s22176677
ISBN
Publisher MDPI
Book Title
ISSN
EISSN 1424-8220
Conference Name
Bibtex ID WOS:000851691300001
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