苯乙烯-马来酸酐交替共聚物钠盐/聚苯乙烯磺酸钠复合物的湿敏特性

摘要

以苯乙烯-马来酸酐交替共聚物钠盐(NaSMA)与聚苯乙烯磺酸钠(NaPSS)复合物为湿敏材料,在叉指金电极上浸涂成膜制备了电阻型湿度传感器,考察了NaSMA和NaPSS浓度对复合湿度传感器响应特性的影响.研究表明,加入NaPSS可降低传感器在低湿下电阻,同时提高传感器的高湿灵敏度.在最佳条件下,当环境湿度从33%RH增加至97%RH时,制备的复合湿度传感器的电阻由4.2×106Ω变化至1.8x103Ω,并具有优异的半对数线性、较高的高湿响应灵敏度和较小的湿滞.相对于单独以NaPSS或NaSMA为湿敏材料的传感器,复合传感器具有更好的综合性能.在复合敏感膜外施加硅丙树脂保护层,可明显提高传感器的稳定性.%Resistive-type humidity sensors based on a composite of sodium poly (styrene-alt-maleic anhydride )(NaSMA) and sodium polystyrenesulfonate (NaPSS) were fabricated by dip coating the aqueous solution of the composite onto interdigitated gold electrodes. The effect of the concentration of both NaSMA and NaPSS on the humidity sensing properties of the composite sensors has been investigated over a wide range of relative humidity(RH) (33％RH ～97％ RH). It was found that the introduction of NaPSS into the composite not only decreased the impedance of the composite at low humidity but also improved the sensitivity at high humidity. Under optimal conditions, the composite sensor exhibited impedance change from 4.2×l06 Ω to 1.8×103 Ω when humidity increased from 33％RH ～ 97％ RH, showing high sensitivity. Moreover, good sensing linearity on a semi-logarithmic scale and relatively small hysteresis were observed. The composite humidity sensor showed better sensing properties than that based on NaSMA or NaPSS alone. In addition, it was found that applying a protective layer of silicone-acrylic resin on the composite sensor its stability under humid environment can be greatly improved.