掺盐MEBA-co-KH570共聚物的湿敏性能

采用甲基丙烯酸二甲氨基乙酯的溴代丁烷季铵盐和硅烷偶联剂KH570的共聚物作为感湿聚合物,并向该聚合物中掺杂LiCl、CaCl2、FeCl33种不同的盐类,制备了高分子电阻型湿敏元件,系统研究了聚合物浓度、无机盐的种类和浓度对元件湿敏性能的影响。结果表明,在33%～95%RH湿度范围内,元件显示出较高的灵敏度(b为-0.043 8～-0.038 8)和较好的线性(R为-0.994 8～-0.981 6),且阻抗随聚合物浓度的增加而下降,但响应变慢;掺杂LiCl和CaCl2可使元件阻抗变小,掺杂FeCl3却使元件阻抗增大;在1×10-2mol/L的最佳LiCl掺杂浓度下,元件具有最好的灵敏度(b=-0.044 6)和最短的脱湿时间(20 s)。

Humidity-sensitive Properties Based on Salts-doped MEBA-co-KH570 Copolymer

Several resistive-type humidity sensors were prepared from copolymer of 2-(methacryloyloxy)ethyl]dimethyl butyl ammonium bromide(MEBA) and γ-methacryloxypropyl trimethoxy silane(KH570) and used as humidity-sensitive material, which were respectively doped with inorganic salt LiCl, CaCl_2 or FeCl_3. The effects of concentrations of polymer, type of doped inorganic salt, doping concentration of salt on humidity-sensitive properties of the humidity sensors were examined. The experimental results show that these humidity sensors exhibited high sensitivities(b=-0.043 8~-0.038 8) and good linearities(R=-0.994 8～-0.981 6) in a humidity range of 33%～95%RH. Increasing the concentration of polymer resulted in impedance, decrease but slower response. In addition, doping LiCl and CaCl_2 caused the impedance decreases, while FeCl_3 doping exhibited a different behavior. At an optimal doping concentration (1×10~(-2) mol/L) of LiCl, the sensor exhibits the best sensitivity(b=-0.044 6) and the shortest desorption time(20 s).