Preparation and Application of C60-Cryptand Coated Surface Acoustic Wave Sensor

• Main Authors: Hung-Bin Lin, 林宏斌
• Other Authors: Jeng-Shong Shin
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/69678926488799326764

碩士 === 國立臺灣師範大學 === 化學研究所 === 90 === Preparation and Application of C60-Cryptand Coated Surface Acoustic Wave Sensor Abstract A C60-cryptand [2,2] coated surface acoustic wave (SAW) detection system was prepared and applied as Gas Chromatographic detector for various vapors. The frequency of surface acoustic wave oscillator decrease due to the adsorption of gas molecules on C60-cryptand [2,2] . The C60-cryptand [2,2] coated surface acoustic wave sensor was used to measure various organic moleculesr and CO gas. A software was written to control the interface and data acquisition. In the stationary system, three coating materials (C60, cryptand [2,2] and C60-cryptand [2,2] ) was tested in organic molecules. The C60-cryptand [2,2] coated SAW dector exhibited more sensitive to polar molecule than Fullerene or cryptand [2,2] coated system respectively. Effect of functional groups, molecular weight, steric hindrance and polarity of organic molecules in both static and flow cell on frequency response of surface acoustic wave sensor had been investigated. The frequency shifts of the C60-cryptand [2,2] coated SAW sensor for various organic molecules and isomer in the order: Alcohols (ROH) > Aldehydes (RCHO) > Ketones (RCOR’); 1-Hexyne>1-Hexene >n-Hexane; Aromatic > cyclo-Alkane > Alkane; 10alcohol > 20alcohol > 30alcohol. The greater frequency shift of a molecule with large molecular weight, less steric hindrance and more polar molecule (especially can form hydrogen bond) was funded. The adsorption of C60-cryptand [2,2] to most organic molecules was found to be physical adsorption(a reversible type) ,which could be desorbed by introducing N2 gas. The detection system also showed the good detection limit of 0.2~3 mg/L for organic molecules. The frequency response of C60-cytptand[2,2] coated SAW for various organic molecules in the flow system showed quite accordance with that in static system. In the application of Gas Surface acoustic Wave (GC-SAW) in GC, the C60-cryptand[2,2] SAW sensor showed higher selectivity than the TCD for polar organic molecules. In CO gas study, various metal-ion/C60-cryptand[2,2] adsorbents, e.g. Ti4+/C60-cryptand [2,2]; Co2+/C60-cryptand [2,2]; Al3+/C60-cryptand, were used to adsorb and detect CO gas. The Co2+/C60-cryptand [2,2] coated SAW sensor exhibited more sensitive than another adsorbent for CO gas. It also showed no significant effect for anion group (e.g. SO42-; NO3-; Cl-). The detection limit of the SAW sensor for CO was found to be about 0.13 ppm.