Research On Sensitive Property Of Cyclodextrin-polymer Optical Waveguide Sensor

Chemical sensor is the instrument that can identify and detect the chemicalsubstance and then experiment consequent can replaced electric signal. With thedevelopment of science and technology, chemical sensors possess widespreadapplications in the area of scientific, industrial and military. However Gas-Sensingmaterial is a core part of the sensor device. Therefore, the research and developmentof the polymer composite materials has wide application prospects and importanttheoretical significance and researcher has been concerned. Gas-Sensing material hasmany different types. Among that, polymer materials due to be low cost, simplemodified of physical and chemical properties, so it plays a decisive role in thedevelopment of sensors.Optical waveguide sensor has the characteristics of flexibility, high sensitivity tothe choice of sensitive reagents, fast response, low cost and other many features.Therefore, it has wide application prospects in the field of environmental monitoring,chemical and biological monitoring. The optical waveguide sensor technology canplay a better value in the area of gas detection.The article began by describing the poisoning effect of the human and theapplication of supramolecular compounds in the sensor field, we introduced thedetected object and detection methods of the supramolecular derivatives as a sensitivereagent. Meanwhile, we also introduced the importance of optical waveguidechemical sensors in the analysis of the field and its working principle andcharacteristics.Here, β-cyclodextrin(β-CD), polyvinylpyrrolidone(PVP), tert-butylcalix[6]arene,bromophenol blue material as the waveguide main sensitive materials. Opticalwaveguide gas chemical sensors were designed and fabricated. And its response to thevolatile organic gases was studied. The main contents were listed below.1. Polymer gas-sensing material has the important characteristics of low cost,easymodification, so they are widely used in the sensor field. In the second chapter,β-cyclodextrin was used as sensitive material, the β-cyclodextrin/K⁺-exchanged optical waveguide sensor was fabricated. Meanwhile, the best condition tofabricate the sensing element was selected (solvent, the concentration ofsensitive reagent, the speed of spin-coating machine). The OWG sensor wasused to detect Volatile Organic Compounds gas. The sensing principle wasstudied by the change of optical characteristics of sensitive film. Theexperiment result indicated that the minimum concentration of detection tostyrene gas of sensor is1×10^-5(43.3mg/m3).2. Chapter third is based on chapter second, the β-cyclodextrin thin film wasmodified. In this chapter, we first choice adequate PVP, and we choose certainamount of PVP and β-cyclodextrin as the sensitive reagents. And thePVP-cyclodextrin/K⁺-exchanged OWG sensor was fabricated by spin-coatingmethod. And the sensitive characteristics of the sensor device was detected. Theexperiment results indicated that, the minimum concentration of detection tostyrene gas of sensor is1×10^-6(4.3mg/m³).while the concentration of the gaseswas1×10^-3, the response of sensor to methanol, ethanol and formaldehyde wassmall. In addition, the infrared spectroscopy of PVP-cyclodextrin film wasmeasured and the interaction between them was studied.3. In the fourth chapter, the β-cyclodextrin film was modified. In this chapter, wefirst decided the certain amount of BPhB, and then chose the appropriate speedof spin-coating machine. The BPhB-cyclodextrin composite film/K⁺-exchangedOWG sensor was fabricated by spin-coating method. And carried out theVolatile Organic Compounds gas detection. Meanwhile, the sensitiveperformance to acidity of sensor device was studied. The experiment resultsindicated that, the sensor device has high response to xylene and the minimumdetection concentration of1×10^-6(4.41mg/m3). Meantime, has good responseto SO2and NH3, but it has slow recovery time to acidic gases.4. Sensor technology can provide low-cost device, therefore, an adjustable sensorsensitive material has wide application of new material in the sensor field. In thefifth chapter,4-tert-butylcalix[6]arene was selected as sensitive material. The4-tert-butylcalix[6]arene/K⁺-exchanged OWG sensor was fabricated by spin-coating method. And the sensitive performance to VOC was detected andthe sensing principle was studied. The experiment results indicated that, thesensor device has good selective response to styrene and the minimum detectionconcentration was1×10^-7(0.43mg/m³). In addition, the sensitive characteristicsof sensor device to chlorobenzene and toluene was researched.