Guadagno Liberata, Longo Raffaele, Aliberti Francesca, Lamberti Patrizia, Tucci Vincenzo, Pantani Roberto, Spinelli Giovanni, Catauro Michelina, Vertuccio Luigi
Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
Department of Information and Electrical Engineering and Applied Mathematics University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
Nanomaterials (Basel). 2023 Jan 26;13(3):495. doi: 10.3390/nano13030495.
This work proposes nanocomposites with carbon nanotubes characterized by self-sensing and self-heating properties. Recently, a growing interest in these two properties has been found in many industrial sectors, especially in the aerospace and automotive fields. While the self-sensing function allows diagnosing the presence of micro-damage in the material thanks to the detection of residual resistance, the self-heating function is exploited to properly tune the heating performance in terms of the heating rate and final temperature values. An electrical percolation value of around 0.5% by weight of carbon nanotubes was found by electrical characterization. The AC conductivity of the nanocomposites, in the range of 100 Hz to 1 MHz, evidences that beyond a CNTs amount of 0.5% wt/wt, they are characterized by a purely resistive behavior. The self-sensing analysis displayed a gauge factor value of 4.1. The solid thermal stability up to 300 °C makes the material suitable as a heating element at high temperatures. SEM investigations and temperature maps evidence a good dispersion of the conductive filler in the epoxy matrix and, consequently, good isotropy in heat distribution. As regards the trend of electrical resistance by varying the temperature, the electro-thermal investigation has shown the presence of both Positive Temperature Coefficient (PTC) and Negative Temperature Coefficient (NTC) behaviors with a predominance of NTC as soon as the temperature becomes closer to the glass transition temperature of the epoxy resin.
这项工作提出了具有自传感和自热特性的碳纳米管纳米复合材料。最近，在许多工业领域，尤其是航空航天和汽车领域，人们对这两种特性的兴趣日益浓厚。自传感功能可通过检测残余电阻来诊断材料中微损伤的存在，而自热功能则用于根据加热速率和最终温度值来适当调节加热性能。通过电学表征发现碳纳米管的电渗流值约为0.5%（重量）。纳米复合材料在100 Hz至1 MHz范围内的交流电导率表明，当碳纳米管含量超过0.5%（重量/重量）时，它们具有纯电阻行为。自传感分析显示应变片系数值为4.1。高达300°C的固体热稳定性使该材料适合作为高温加热元件。扫描电子显微镜研究和温度分布图证明了导电填料在环氧基质中的良好分散性，因此热分布具有良好的各向同性。关于电阻随温度变化的趋势，电热研究表明存在正温度系数（PTC）和负温度系数（NTC）行为，一旦温度接近环氧树脂的玻璃化转变温度，NTC行为占主导。
