Procek Marcin, Kepska Kinga, Stolarczyk Agnieszka
Department of Optoelectronics, Silesian University of Technology, 2 Krzywoustego Street, 44-100 Gliwice, Poland.
Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 9 Strzody Street, 44-100 Gliwice, Poland.
Sensors (Basel). 2018 Mar 20;18(3):928. doi: 10.3390/s18030928.
The detection and concentration measurements of low concentrations of nitrogen dioxide (NO₂) are important because of its negative effects on human health and its application in many fields of industry and safety systems. In our approach, conducting graft copolymers based on the poly(3-hexylthiophene) (P3HT) conducting polymer and other side-chains, polyethylene glycol (PEG) and dodec-1-en, grafted on a poly(methylhydrosiloxane) backbone, were investigated. The grafts containing PEG (PEGSil) and dodec-1-en (DodecSil) in two variants, namely, fractions with shorter (hexane fraction -H) and longer (chloroform fraction -CH) side-chains of P3HT, were tested as receptor structures in NO₂ gas sensors. Their responses to NO₂, within the concentration range of 1-20 ppm, were investigated in an nitrogen atmosphere at different operating temperatures-room temperature (RT) = 25 °C, 50 °C, and 100 °C. The results indicated that both of the copolymers with PEG side-chains had higher responses to NO₂ than the materials with dodec-1-en side-chains. Furthermore, the results indicated that, in both cases, H fractions were more sensitive than CH fractions. The highest response to 1 ppm of NO₂ from the investigated graft copolymers, had PEGSil H, which indicated a response of 1330% at RT and 1980% at 100 °C. The calculated lower-limit of the detection of this material is lower than 300 ppb of NO₂ at 100 °C. This research indicated that graft copolymers of P3HT had great potential for low temperature NO₂ sensing, and that the proper choice of other side-chains in graft copolymers can improve their gas sensing properties.
低浓度二氧化氮（NO₂）的检测和浓度测量非常重要，因为它对人体健康有负面影响，并且在许多工业和安全系统领域都有应用。在我们的方法中，研究了基于聚（3-己基噻吩）（P3HT）导电聚合物和其他侧链（聚乙二醇（PEG）和十二碳-1-烯）接枝在聚（甲基氢硅氧烷）主链上的导电接枝共聚物。含有PEG（PEGSil）和十二碳-1-烯（DodecSil）的两种变体接枝物，即具有较短（己烷馏分-H）和较长（氯仿馏分-CH）P3HT侧链的馏分，被测试作为NO₂气体传感器中的受体结构。在氮气气氛中，于不同操作温度（室温（RT）=25°C、50°C和100°C）下研究了它们对1-20 ppm浓度范围内NO₂的响应。结果表明，两种带有PEG侧链的共聚物对NO₂的响应都高于带有十二碳-1-烯侧链的材料。此外，结果表明，在两种情况下，H馏分比CH馏分更敏感。在所研究的接枝共聚物中，对1 ppm NO₂响应最高的是PEGSil H，其在室温下的响应为1330%，在100°C时为1980%。该材料在100°C时计算出的检测下限低于300 ppb的NO₂。这项研究表明，P3HT接枝共聚物在低温NO₂传感方面具有巨大潜力，并且在接枝共聚物中适当选择其他侧链可以改善其气敏性能。
