基于c‒MWCNTs/GO体系的湿敏型智能包装研究

Humidity Sensitive Intelligent Packaging Based on c-MWCNTs/GO

目的优选羧基化多壁碳纳米管(c-MWCNTs)与氧化石墨烯(GO)作为敏感材料制备湿度传感器,对其湿敏特性进行研究,探索一种能够快速精确监测包装内湿度变化的传感器。方法通过丝网印刷工艺印制传感器电极基底,在电极表面涂布c-MWCNTs/GO湿敏溶液,混合湿敏溶液中c-MWCNTs的质量分数分别为20%和67%,烘干后得到电阻型湿度传感器,测定其灵敏度、动态响应、响应恢复时间、吸湿滞后性、重复性等湿敏特性。结果选用长度为0.5~2μm的c-MWCNTs制备的湿度传感器灵敏度、线性度优于10~30μm的。质量分数分别为20%和67%的c-MWCNTs的湿敏溶液制备而得的传感器均对不同湿度敏感,而当c-MWCNTs质量分数为67%时灵敏度更高,线性度更好,在低湿(相对湿度为33%)时响应和恢复时间分别为7 s和3.9 s,高湿(相对湿度为85%)时分别为20 s和15 s,最大吸湿滞后值为17%。结论将c-MWCNTs与GO掺杂用于制备湿度传感器,可以检测的相对湿度范围为11%~98%,且c-MWCNTs质量分数为67%时传感器具有较高的灵敏度、良好的线性度、良好的重复性、快速的响应恢复能力和较小的吸湿滞后,在未来包装湿度监控应用方面具有广阔前景。

The work aims to preferably select carboxylated multi-walled carbon nanotubes(c-MWCNTs)and graphene oxide(GO)as sensitive materials to prepare humidity sensor and study the humidity sensitivity characteristics of the sensor to explore a novel sensor that can quickly and accurately monitor the humidity changes in the packaging.The sensor electrode substrate was printed by screen printing process,and the c-MWCNTs/GO humidity sensitive solution was coated on the electrode surface.The mass fraction of c-MWCNTs in the mixed humidity sensitive solution was 20%and 67%,respectively.After drying,a resistive humidity sensor was prepared.The sensitivity,dynamic response,response recovery time,hygroscopic lag and other hygroscopic sensitive characteristics were measured.The humidity sensor pre-pared with c-MWCNTs of length 0.5~2μm had better sensitivity and linearity than those prepared by c-MWCNTs of 10~30μm.The sensor prepared with 20%and 67%mass fraction of c-MWCNTs in the humidity sensitive solution was sensitive to different humidity levels,and the sensitivity and linearity were higher when the mass fraction of c-MWCNTs was 67%.The response and recovery times were 7 s and 3.9 s,respectively at low humidity(33%RH)and 20 s and 15 s,respectively at high humidity(85%RH).The maximum hygroscopic lag value was 17%.The c-MWCNTs can be doped with GO to prepare humidity sensor,which can detect the changes of relative humidity from 11%to 98%,and the sensor prepared by 67%mass fraction of c-MWCNTs has high sensitivity,good linearity,excellent repeatability,fast response recovery and small hygroscopic hysteresis,thus having a broad prospect in the future application of packaging humidity monitoring.