TY - JOUR
T1 - Carbon nanotubes as a chemical sensor
AU - Sumanasekera, G. U.
AU - Pradhan, B. K.
AU - Adu, C. K.W.
AU - Romero, R. E.
AU - Eklund, P. C.
PY - 2004/9
Y1 - 2004/9
N2 - A systematic study of the changes in the thermoelectric power (TEP) and four-probe resistance of vacuum-degassed thin films of nanotube bundles induced by the adsorption of polar alcohols and water six-membered ring molecules was presented. A strong effect on both the TEP, represented by S, and resistivity was found for methanol, ethanol, isopropanol, and butanol. For these four compounds, the TEP increased exponentially with time from the degassed value S0 ∼ -2.7 μV/K to a higher plateau after ∼ 1 hr. For methanol and ethanol, S was even driven positive, saturating at Smax ∼ +1.1 and +0.1 μV/K, respectively. Exposure to larger alcohol molecules, i.e., isopropanol and butanol, led to smaller changes in S and saturation at Smax ∼ -0.5 and -1.0 μV/K, respectively. Exposure to water vapor induced virtually no change in the TEP. S exhibited a linear relationship with ΔR/R0, consistent with the creation of a new impurity scattering channel via physisorption.
AB - A systematic study of the changes in the thermoelectric power (TEP) and four-probe resistance of vacuum-degassed thin films of nanotube bundles induced by the adsorption of polar alcohols and water six-membered ring molecules was presented. A strong effect on both the TEP, represented by S, and resistivity was found for methanol, ethanol, isopropanol, and butanol. For these four compounds, the TEP increased exponentially with time from the degassed value S0 ∼ -2.7 μV/K to a higher plateau after ∼ 1 hr. For methanol and ethanol, S was even driven positive, saturating at Smax ∼ +1.1 and +0.1 μV/K, respectively. Exposure to larger alcohol molecules, i.e., isopropanol and butanol, led to smaller changes in S and saturation at Smax ∼ -0.5 and -1.0 μV/K, respectively. Exposure to water vapor induced virtually no change in the TEP. S exhibited a linear relationship with ΔR/R0, consistent with the creation of a new impurity scattering channel via physisorption.
UR - http://www.scopus.com/inward/record.url?scp=4544315322&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4544315322&partnerID=8YFLogxK
M3 - Conference article
AN - SCOPUS:4544315322
SN - 0569-3772
VL - 49
SP - 885
EP - 886
JO - ACS Division of Fuel Chemistry, Preprints
JF - ACS Division of Fuel Chemistry, Preprints
IS - 2
ER -