Humidity Sensing Performance of MWCNT/Nafion/MWCNT Composites
WANG Yanjie1, ZHAO Shijie1,2, SHENG Junjie3,*, RU Jie2, ZHAO Chun1,2, LI Shuyong3
1 College of Mechanical and Electrical Engineering, Hohai University, Changzhou 213022, Jiangsu, China 2 Jiangsu Key Laboratory of Special Robotics Technology, Changzhou 213022,Jiangsu, China 3 China Academy of Engineering Physics, Mianyang 621900, Sichuan, China
Abstract: The development of new humidity sensors is of great importance to meet the industrial and agricultural humidity detection. As a key component of a humidity sensor, the humidity-sensitive material directly affects the performance of the sensor.Ionic polymer-metal-composite (IPMC) can be used as a new type of flexible sensor. The movable ions inside the ionomer will undergo directional migration to form a potential difference under the action of external dynamic humidity, thereby generating an electrical signal. Because of excellent humidity-sensing properties, IPMC sensors have attracted increasing attention in the field of precision monitoring of ambient humidity. However, the electrode layer of the existing IPMC sensors is dense, which makes it difficult for quickly exchange humidity with the external environment. In addition, the weak adhesion between the electrode layer and the ionomer membrane causes the electrode to fall off easily. In order to solve the problem that the electrode layer is too dense, multi-walled carbon nanotubes (MWCNT), polyvinylidene fluoride (PVDF-HFP) and ionic liquids (ILs) have been used to cast the composite electrode layer with microporous structure for quickly exchange humidity with the external environment. Meanwhile, a binder with ion transport ability has been used between the electrode layer and ionomer membrane to enhance the bonding strength of the electrode during the thermoforming process. This work developed a new kind of ionic polymer (MWCNT/Nafion/MWCNT) composite for humidity sensitive film. Firstly, the multiwalled carbon nanotubes/polyvinylidene fluoride/ionic liquid (MWCNT/PVDF-HFP/ILs) electrode layer and perfluorinated sulfonic acid-polytetrafluoroethy-lene/ionic liquid (Nafion/ILs) electrolyte layer were prepared via solution casting method. The MWCNT/Nafion/MWCNT composite film with humidity sensitive properties was assembled by hot-pressing a Nafion/ILs electrolyte layer between two MWCNT/PVDF-HFP/ILs electrode films. Subsequently, the microstructure and electrochemical characteristics of the composite film were characterized by using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance (EIS), respectively. And the humidity-voltage responses, the humidity sensitivity characteristics and mechanism of the composite film under various humidity conditions were tested systematically. The results show that as the relative humidity ranges from 0%RH and 100%RH, the fastest response time and fastest recovery time of the humidity sensing film are 17 s and 58 s, respectively. The sensitivity of electrical response is 0.14 mV/%RH, and the response rate is up to 0.277 mV/s. Finally, the potential applications of the humidity sensing film in respiration detection, dam seepage detection and other scenarios were investigated and demonstrated.
1 Fahimeh Beigi, Matin Sadat Saneei Mousavi. Applied Clay Science, 2018, 166, 131. 2 Blank T A, Eksperiandova L P, Belikov K N. Sensors & Actuators B: Chemical, 2016, 228, 416. 3 Emad Esmaeli, Mahya Ganjian, Hamed Rastegar, et al. Sensors & Actuators B: Chemical, 2017, 247, 498. 4 Gan X, Zhao C, Yuan Q, et al. Applied Physics Letters, 2017, 110(15), 151107. 5 Ghosh S, Ghosh R, Kumar Guha P. IEEE Transactions on Nanotechnology, 2016, 15(5), 782. 6 Yang F, Zhang L, Yu K, et al. Materials Reports A:Review Papers, 2018, 32(17), 2940(in Chinese). 杨芳, 张龙, 余堃, 等.材料导报:综述篇, 2018, 32(17), 2940. 7 Guo R, Tang W, Shen C T, et al. Computational Materials Science, 2016, 111(1), 289. 8 Igor A Pašti, Aleksandra Janošević Ležaić, Gordana ćirić-Marjanović. Journal of Solid State Electrochemistry, 2016,20(11), 3061. 9 Kei Saotome, Swetha E Murthy, Jennifer M Kefauver. Nature: International Weekly Journal of Science,2018,554(7693), 481. 10 Mohdisa W H, Hunt A, Hosseinnia S H. Sensors,2019,19(18),3967. 11 Tiwari R, Kim K J. Applied Physics Letters, 2010, 97(24), 2441041. 12 Zhu Z, Horiuchi T, Kruusamäe K. Smart Materials and Structures, 2016, 25(5), 055024. 13 Esmaeli E, Ganjian M, Rastegar H, et al. Sensors & Actuators: B. Chemical, 2017, 247, 498. 14 Li T, Li L H, Sun H W. Advanced Science,2017,4(5),1600404. 15 Palmre V, Lust E, Alar J.J. Mater. Chem, 2011, 21(8), 2577. 16 Ghosh S, Ghosh R, Guha P K, et al. IEEE Transactions on Nanotechno-logy, 2016, 15(5), 782. 17 Fahimeh Beigi, Matin Sadat Saneei Mousavi, Faranak Manteghi, et al. Applied Clay Science, 2018, 166, 131. 18 Wang Y J, Wang J L, Hao M Y, et al. RSC Advances, 2020, 10(46), 27447. 19 Takeuchi I, Asaka K, Kiyohara K, et al. Journal of Physical Chemistry C, 2010, 114(34),14627. 20 Esmaeli E, Ganjian M, Rastegar H, et al. Sensors & Actuators B: Chemical, 2017, 247, 498. 21 Jeon J H, Kee C D, Kee C D. Advanced Functional Materials, 2013, 23(48), 6007. 22 Ru J. Performance Improvements and application research of ionic polymer-metal composite (IPMC) artificial muscle. Ph.D. Thesis,Xi’an Jiaotong University, China, 2018(in Chinese). 汝杰. 离子型电活性聚合物人工肌肉的性能改进及应用研究. 博士学位论文,西安交通大学,2018. 23 Khan A, Alamry K A, Jain R K. RSC Advance, 2019, 9(68), 39721. 24 Ru J, Zhu Z, Wang Y. RSC Advance, 2018, 8(6), 3090. 25 Xiaohui Leng, Dan Luo, Zongxiang Xu. Sensors & Actuators B: Chemical, 2018, 257, 372. 26 Liu Y, Chang L, Hu Y. Smart Materials and Structures, 2018, 27(7), 075055. 27 Beers K M, Sergey Y, Andrew J, et al. The Journal of Physical Chemistry B, 2014, 118(24), 6785. 28 Freger V. The Journal of Physical Chemistry B, 2008, 113(1), 24. 29 Jeck S, Scharfer P, Kind M. Journal of Membrane Science, 2011, 373(1), 74. 30 Kuang Q, Lao C, Wang Z L, et al. Journal of the American Chemical Society, 2007, 129(19), 6070
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2022, Vol. 36 
