Application of m-CNTs/NaClO4/Ppy to a fast response, room working temperature ethanol sensor

作者：Wu Ren Jang^*; Huang Yu Ching; Yu Ming Ru; Lin Tzu Hsuan; Hung Shih Lin

来源：Sensors and Actuators B: Chemical , 2008, 134(1): 213-218.

DOI：10.1016/j.snb.2008.04.033

• Polypyrrole
• Multiwall carbon nanotubes (m-CNTs)
• UV-photo polymerization
• Ethanol sensor

A new blended material, m-CNTs/NaClO4/Ppy, was developed as a gas sensor to detect ethanol concentrations at room temperature. The sensing material polypyrrole (Ppy) was synthesized in situ by UV-photo-polymerization. The multiwall carbon nanotubes (m-CNTs) added enhanced the short-term repeatability of the Ppy-sensing material. The relative resistance variation (R-ethanol/R-air) of mCNTs/NaClO4/Ppy was 1.193 when exposed to ethanol of 30,000 ppm. The sensor response and recovery times (both 20s) were very short to this concentration. An unstable baseline of the sensor was explained by theoretical calculation of molecular dynamics made for ethanol adsorption on polypyrrole, which revealed formation of a new bond, N-H center dot center dot center dot O. Adsorption energy decreased with increasing the number of ethanol molecules adsorbed and was 0.8 kcal/mol at eight adsorbed molecules. Sensor responses of three different Ppy samples were measured to ethanol concentrations of 18,000-40,000 ppm.

• 出版日期2008-8-28