Fraunhofer-Institute for Physical Measurement Techniques IPM, Heidenhofstrasse 8, 79110 Freiburg, Germany.
Laboratory for Gas Sensors, Department of Microsystems Engineering-IMTEK, University of Freiburg, Georges-Köhler-Allee 102, 79110 Freiburg, Germany.
Sensors (Basel). 2018 Jun 21;18(7):1994. doi: 10.3390/s18071994.
The detection of the toxic gas carbon monoxide (CO) in the low ppm range is required in different applications. We present a study of the reactivity of different gasochromic rhodium complexes towards the toxic gas carbon monoxide (CO). Therefore, variations of binuclear rhodium complexes with different ligands were prepared. They were characterized by FTIR spectroscopy, ¹H NMR spectroscopy, and differential scanning calorimetry. All complexes are spectroscopically distinguishable and temperature stable up to at least 187 °C. The gasochromic behavior of all different compounds was tested. Therefore, the compounds were dissolved in toluene and exposed to 100 ppm CO for 10 min to investigate their gas sensitivity and reaction velocity. The changes in the transmission spectra were recorded by UV/vis spectroscopy. Furthermore, a significant influence of the solvent to the color dyes’ gasochromic reaction and behavior was observed. After characterization, one complex was transferred as sensing element into an optical gas sensor. Two different measurement principles (reflection- and waveguide-based) were built up and tested towards their capability as gasochromic CO sensors. Finally, different gas-dependent measurements were carried out.
需要在不同应用中检测低 ppm 范围内的有毒气体一氧化碳 (CO)。我们研究了不同变色铑配合物对有毒气体一氧化碳 (CO)的反应性。因此，制备了具有不同配体的双核铑配合物的变化。它们通过傅里叶变换红外光谱、¹H NMR 光谱和差示扫描量热法进行了表征。所有配合物在光谱上都是可区分的，并且在至少 187 °C 下温度稳定。测试了所有不同化合物的变色行为。因此，将化合物溶解在甲苯中，并暴露于 100 ppm CO 中 10 分钟，以研究它们的气体灵敏度和反应速度。通过紫外/可见光谱记录透射光谱的变化。此外，观察到溶剂对显色染料的变色反应和行为有显著影响。表征后，将一个配合物作为传感元件转移到光学气体传感器中。建立了两种不同的测量原理（反射和波导），并对其作为变色 CO 传感器的性能进行了测试。最后，进行了不同的气体依赖性测量。
