干湿变化对多壁碳纳米管/水泥砂浆压阻效应的影响  

Influence of Dry/Wet State Variation on Piezoresistivity of Multi-walled Carbon Nanotube Reinforced Cement Mortar

作　　者：王燕锋 赵晓华[1] 李庚英[1] WANG Yanfeng;ZHAO Xiaohua;LI Gengying(Department of Civil Engineering,Shantou University,Shantou 515063)

机构地区：[1]汕头大学土木工程系,汕头515063

出　　处：《材料导报》2017年第24期20-25,共6页Materials Reports

基　　金：广东省高等教育重点实验室基金(2013CXZDA017);国家自然科学基金(51378303)

摘　　要：通过四次烘干和三次吸湿试验,考察了湿度变化对多壁碳纳米管复合水泥砂浆(MWCNTs/CM)的电阻和压阻效应的影响,并与素水泥砂浆(CM)进行对比。结果表明:在试件湿度较大时,烘干和吸湿对MWCNTs/CM和CM电阻的影响较小,而当试件湿度较低时(第三次烘干及第一次吸湿后,湿度变化比低于1%时),电阻随着湿度的降低突然增加,并且湿度变化对CM电阻的影响程度显著高于MWCNTs/CM。同样,当试件湿度较大时,烘干和吸湿对MWCNTs/CM和CM压阻效应的影响较小,当试件湿度较低时(在第三次烘干后),CM和MWCNTs/CM的压阻效应显著增强,并且湿度变化对CM压阻效应的影响显著高于MWCNTs/CM。研究还表明,在湿度变化量大致相同时,吸湿过程中CM和MWCNTs/CM达到渗流阈值附近时压阻效应高于烘干过程。最后,初步探讨了MWCNTs/CM压阻效应随湿度变化的作用机理,给出了MWCNTs/CM压阻效应随湿度变化的等效电路模型。The influence of water content variation on the resistance and piezoresistivity of multi-wall carbon nanotube reinforced mortar was investigated by means of four times drying and three times wetting experiments.The results were compared with the cement mortar.It showed small impact on resistance and piezoresistivity of specimen with more water content.With decreasing water content,the change of resistance became significant,especially for the cement mortar.The magnitude of the piezoresistivity of composites became large.The piezoresistivity of CM was more sensitive to the change of water than MWCNTs/CM in this case.Moreover,the magnitude of piezoresistivity near the percolation during the wetting process was higher than the drying process.Finally,the mechanisms of piezoresistivity change of MWCNTs/CM were analyzed during the process.The equivalent circuits were obtained to explain the change of conductive network.

关 键 词：多壁碳纳米管 砂浆 压阻效应 干湿变化 等效电路模型 

分 类 号：TQ127.1[化学工程—无机化工]