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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:21 |
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Conference: Bucharest University Faculty of Physics 2010 Meeting
Section: Solid State Physics and Materials Science
Title:
Nitrogen Dioxide Sensor Based on Carbon Nanotubes
Authors:
I.D. Simandan, A. Velea,
C. E. Simion, A. Tomescu, A. Lorinczi
Affiliation:
National Institute of Research & Development for Materials Physics INCDFM
Atomistilor St., P.O. Box MG 7, Bucharest-Magurele, ROMANIA
E-mail
simandan@infim.ro
Keywords:
sensor,nanotube,NO2
Abstract:
Langmuir – Blodgett multilayers have been prepared from Barium Stearate with carbon nanotubes. The dispersion of carbon nanotubes in the mass of the amphiphlic molecules was made possible by the use of a strong sulfonic tensioactive compound. There were prepared differently layers on glass substrate with different concentration of nanotubes.The multilayers without nanotubes show a high electrical resistance(23 GΩ), and those with 0.005 wt% nanotubes a resistence of 20-60 KΩ.There were deposited thin multilayers on alumina substrates equipped with platinum electrodes for testing the sensoring effect.It was observed a strong sensibility of the tested material at low concentrations of NO2 such as 2.5 ppm at 50oC and 100oC.The material is not sensitive at other gasses such as carbon oxide or methane.The lowering of the electrical resistance, under a minimum concentration of NO2 is 5,68% for the probe with 0.005 wt% nanotubes and 4.27% for the probe with 0.01 wt% nanotubes.The desorption of the nitrogen dioxide and the upcoming to the initial resistance of the material could be achieved by heating the sensor above some critical temperature specific of the NO2-carbon nanotube interaction.The NO2 gas sensor has the advantage of functionality at near room temperatures, great sensibility factor (1.99) at low concentration of gas and a very good. The purpose of this sensor is the detection of NO2 gas in industrial processes and in the prevention of chemical terrorism.
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