摘要
研究了不同配比导电炭黑和羟乙基纤维素(HEC)感湿胶制备的碳湿敏元件的感湿特性,探讨了山梨醇增湿剂对感湿非线性特性的影响。对碳湿敏元件的体积电阻率、湿敏特性和复阻抗谱的测试结果表明,炭黑含量和山梨醇含量对非线性感湿特性有很大影响,2%炭黑试样在80%湿度附近开始出现电阻的非线性增大;适量山梨醇使试样的非线性湿度响应移向较低湿度区。试样的复阻抗谱在54%湿度时为1个带拖尾的半圆弧,80%湿度时变为带拖尾的2个半圆弧,更高湿度时是拖尾拉长变形明显的2个半圆弧,表明其等效电路是由包括体电阻、炭黑粒界电阻和电极接触电阻三个阻容并联体的串联组成。半圆弧数目随湿度增加的现象,与感湿膜中水分子增加使不同极化机制的作用变得更加明显有关。
The humidity-sensing property of carbon black（CB）/hydroxyethyl cellulose（HEC） humidity sensors and its dependence on the chemical composition of the sample were investigated. Sorbitol was incorporated into the samples as a sensitizing agent and its effect on the nonlinearity of the devices＇ performance was studied. The measurement results of conductivity, sensitivity to humidity and complex impedance spectrum （CIS） suggest that the amounts of CB and sorbitol affect the sensing performance greatly. A nonlinear increase in resistance was observed at 80% humidity on the sample with 2% CB, and the sensitivity response shifts to lower humidity values when an appropriate amount of sorbitol is added. The sensor＇s equivalent circuits derived from the CIS results can be modeled by a Warburg impedance in series with a number of resistance-capacitance circuits that correspond to bulk resistance, CB-grain-boundary resistance and contact resistance, respectively. The number of semicircles in the CIS increases with humidity level, which indicates different polarization mechanisms due to the adsorbed water.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2009年第1期200-204,共5页
Acta Materiae Compositae Sinica
基金
广州市科技计划项目(2007J1-C0341)
广州市属高校科技计划项目(62015)
关键词
碳湿敏元件
羟乙基纤维素
山梨醇
感湿性能
复阻抗谱
carbon humidity sensor
hydroxyethyl cellulose
sorbitol
humidity- sensing property
complex impedance spectroscopy
