High-temperature piezoelectric sen-sors are very important in severe environments such as fire safety,aerospace and oil drills,however,most current sensors are not heat res-istant(<300℃)and are fragile,which limit...High-temperature piezoelectric sen-sors are very important in severe environments such as fire safety,aerospace and oil drills,however,most current sensors are not heat res-istant(<300℃)and are fragile,which limits their use,especially in high-temperature environ-ments.A high-temperature resistant flexible piezoelectric film based on graphene oxide(GO)/polyacrylonitrile(PAN)composites was prepared by electrospinning and thermal treat-ment.It was packed into a micro-device,which could work continuously at 500℃.The intro-duction of GO significantly increased the mechanical properties of the PAN nanofibers because the oxygen-containing func-tional groups(electronegative groups)on the surface of the GO initiated a nucleophilic attack on the PAN molecule during heat treatment,enabling the GO to initiate the cyclization of the PAN at lower heat-treatment temperatures.In addition,the abund-ant oxygen-containing functional groups on GO acted as pro-oxidants to hasten the oxidation of PAN during heat treatment.The effects of GO content and heat treatment temperature on the properties of the nanofiber films were investigated.A GO/PAN nanofiber piezoelectric sensor heat-treated at 300℃had a 9.10 V and 2.25μA peak output,which are respectively 101.3%and 78.6%higher than those of the untreated films.Cyclic testing over 5000 cycles at 350℃confirmed the stable out-put performance of the GO/PAN nanofiber piezoelectric sensor.Furthermore,a sensor heat-treated at 400℃had a sensitivity of 1.7 V/N,which is 83.5%higher than that of an untreated one.The results show that the prepared GO/PAN nanofiber piezo-electric sensor combines high temperature resistance,high flexibility,stability and high sensitivity,and may have broad applic-ations in high temperature environments such as the aerospace and petroleum industries.展开更多
挠曲电效应广泛应用于柔性传感、医疗复健、振动能量收集等领域,然而尚未有研究探讨挠曲形变量对挠曲电响应性能的影响。基于此,以MoS_(2)/PAN复合挠曲电传感薄膜为例,制备MoS_(2)/PAN弯曲传感器,采用X射线衍射仪和扫描电子显微镜对复...挠曲电效应广泛应用于柔性传感、医疗复健、振动能量收集等领域,然而尚未有研究探讨挠曲形变量对挠曲电响应性能的影响。基于此,以MoS_(2)/PAN复合挠曲电传感薄膜为例,制备MoS_(2)/PAN弯曲传感器,采用X射线衍射仪和扫描电子显微镜对复合挠曲电传感薄膜的晶体结构、微观形貌进行表征。在弯曲角度为0.1°、0.5°、1.5°、4°、7°、15°、30°和45°情况下,通过数字源表收集不同弯曲角度下MoS_(2)/PAN弯曲传感器的挠曲响应电压、电流和响应时间,分析挠曲形变量对挠曲电响应性能的影响规律,基于悬臂梁方法测试计算挠曲电系数。结果表明:MoS_(2)/PAN弯曲传感器挠曲电效应显著,挠曲电系数高达1.95 n C/m,当弯曲角度为7°时,MoS_(2)/PAN弯曲传感器获得最优的挠曲电响应,当弯曲角度小于7°时,挠曲电响应随弯曲角度的增大而增大,但是当弯曲角度大于7°时,挠曲电效应减弱。展开更多
文摘High-temperature piezoelectric sen-sors are very important in severe environments such as fire safety,aerospace and oil drills,however,most current sensors are not heat res-istant(<300℃)and are fragile,which limits their use,especially in high-temperature environ-ments.A high-temperature resistant flexible piezoelectric film based on graphene oxide(GO)/polyacrylonitrile(PAN)composites was prepared by electrospinning and thermal treat-ment.It was packed into a micro-device,which could work continuously at 500℃.The intro-duction of GO significantly increased the mechanical properties of the PAN nanofibers because the oxygen-containing func-tional groups(electronegative groups)on the surface of the GO initiated a nucleophilic attack on the PAN molecule during heat treatment,enabling the GO to initiate the cyclization of the PAN at lower heat-treatment temperatures.In addition,the abund-ant oxygen-containing functional groups on GO acted as pro-oxidants to hasten the oxidation of PAN during heat treatment.The effects of GO content and heat treatment temperature on the properties of the nanofiber films were investigated.A GO/PAN nanofiber piezoelectric sensor heat-treated at 300℃had a 9.10 V and 2.25μA peak output,which are respectively 101.3%and 78.6%higher than those of the untreated films.Cyclic testing over 5000 cycles at 350℃confirmed the stable out-put performance of the GO/PAN nanofiber piezoelectric sensor.Furthermore,a sensor heat-treated at 400℃had a sensitivity of 1.7 V/N,which is 83.5%higher than that of an untreated one.The results show that the prepared GO/PAN nanofiber piezo-electric sensor combines high temperature resistance,high flexibility,stability and high sensitivity,and may have broad applic-ations in high temperature environments such as the aerospace and petroleum industries.
文摘挠曲电效应广泛应用于柔性传感、医疗复健、振动能量收集等领域,然而尚未有研究探讨挠曲形变量对挠曲电响应性能的影响。基于此,以MoS_(2)/PAN复合挠曲电传感薄膜为例,制备MoS_(2)/PAN弯曲传感器,采用X射线衍射仪和扫描电子显微镜对复合挠曲电传感薄膜的晶体结构、微观形貌进行表征。在弯曲角度为0.1°、0.5°、1.5°、4°、7°、15°、30°和45°情况下,通过数字源表收集不同弯曲角度下MoS_(2)/PAN弯曲传感器的挠曲响应电压、电流和响应时间,分析挠曲形变量对挠曲电响应性能的影响规律,基于悬臂梁方法测试计算挠曲电系数。结果表明:MoS_(2)/PAN弯曲传感器挠曲电效应显著,挠曲电系数高达1.95 n C/m,当弯曲角度为7°时,MoS_(2)/PAN弯曲传感器获得最优的挠曲电响应,当弯曲角度小于7°时,挠曲电响应随弯曲角度的增大而增大,但是当弯曲角度大于7°时,挠曲电效应减弱。
