Doping Of Carbon Nanotubes By Polyaniline And Its Application In Gas Sensor

Carbon nanotubes(CNTs) has porous microstructure and high surface area, so has strong absorption for some gas, which makes it a promising future as sensitive material. It is found that polyaniline(Pani) also has a certain gas sensor response characteristics. The characteristics of gas sensors based on carbon nanotubes doped Fani is significantly higher. Have this in mind, we do the following works:In this paper, we prepared polyaniline using the method of in-sute polymerization. And we control the ordered arragement of carbon nanotubes and Pani by using electrophoresis (DEP).The parameters we optimize are amplitude, frequency and time of the electric field. We also test the gas sening characteristics to ammonia of the two materials, and we certify the conclusion from response time, recovery time, linear degrees.Carbon nanotube and Polyaniline composite for gas sensing were investigated in this paper. Pani coated multi-walled carbon nanotube (MWNT) was synthesized by means of in-sute polymerization and dielectrophoresis. The nano-composite sensor showed a 3.4 reversible resistance change to lOppm NH3 with a response time of 15s while the sensitivities of Pani film sensor is 1.9 in the contrast experiment. The results indicate that the nano-composite sensitivity and sensing dynamic are improved due to the nanostructure with ultra-high surface-volume ratio and good conductivity. The mechanism of sensitivity to NH3 of the sensor was also discussed.In addition, we also use the method of direct scattered to prepare carbon nanotubes doped polyaniline.The mixed gas sensor response is 2.837 to ammonia in our experiment.And compared to pure CNT,the response time shortens greatly, the recovery time is just slightly longer, and the desorption is better.In conclusion,the gas sensor based on the CNT doped Pani has a better application prospect. The methods we use not only overcome the low defects of CNT gas scnsors,but also enhance the nano structure characteristics of polyaniline, which makes the composite material a star material for ammonia detection.