基于分子筛薄膜探测神经类毒气的传感器研究

Research on nerve agent gas sensor based on zeolite films

采用ZSM-5分子筛材料对神经类毒剂沙林的相似物甲基磷酸二甲脂(DMMP)气体进行了测试。分子筛材料因为具有选择性吸附分子的能力常被用来作为气体敏感材料,但因为其神经类气体极性较强,被吸附后难于解吸附,因此,分子筛材料很少用于检测神经类气体。利用合成的ZSM-5纳米分子筛作为吸附神经类气体DMMP的敏感材料,将其涂布在2个石英晶体微天平(QCM)上进行差频测试,以减小外界的干扰,并提出了用交变电场进行极性分子解吸附的新方法。DMMP气体的探测最小体积分数达到1×10-6,响应时间和解吸附时间分别小于20 s和90 s。

The nerve agent simulant dimethyhnethylphosphonate（DMMP） has been tested with this piezoelectric sensor devices coated with nanosize ZSM-5 zeolite films. The zeolite has been often utilized as the gas sensing material for its molecular sieving properties, but there is seldom report on nerve gas detection based on this material because the never gas is the strong polar molecule. Therefore, a new type of ZSM-5 nano-zeolite especially sensitive to DMMP is synthesized and deposited on two mass sensor quartz crystal microbalance（QCM） and the difference frequency has been examined to reduce outside interference. The desorption method has been developed by using alternant electric field. Volume fraction of DMMP gas is 1 ×10 ^-6. The response time of absorption and desorption is 20 s and 90 s respectively.