Wu Jima, Fu Yuheng, Hu Guo-Hua, Wang Shan, Xiong Chuanxi
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Université de Lorraine-CNRS, Laboratory of Reactions and Process Engineering (LRGP, UMR CNRS 7274), 1 rue Grandville, BP 20451, 54001 Nancy, France.
Polymers (Basel). 2021 Jun 22;13(13):2037. doi: 10.3390/polym13132037.
Compared to polyvinylidene fluoride (PVDF) and its copolymers, castor-oil-derived nylon-11 has been less explored over the past decades, despite its excellent piezoelectric properties at elevated temperatures. To utilize nylon-11 for future sensor or vibrational energy harvesting devices, it is important to control the formation of the electroactive δ' crystal phase. In this work, nylon-11 films were first fabricated by solution-casting and were then uniaxially stretched at different stretching ratios (SR) and temperatures (T) to obtain a series of stretched films. The combination of two-dimensional wide-angle X-ray diffraction (2D-WAXD) and differential scanning calorimetry (DSC) techniques showed that the fraction of the δ' crystal phase increased with the stretching ratio and acquired a maximum at a T of 80 °C. Further, it was found that the ferroelectric and piezoelectric properties of the fabricated nylon-11 films could be correlated well with their crystalline structure. Consequently, the stretched nylon-11 film stretched at an SR of 300% and a T of 80 °C showed maximum remanent polarization and a remarkable piezoelectric coefficient of 7.2 pC/N. A simple piezoelectric device with such a nylon-11 film was made into a simple piezoelectric device, which could generate an output voltage of 1.5 V and a current of 11 nA, respectively.
与聚偏二氟乙烯（PVDF）及其共聚物相比，尽管蓖麻油衍生的尼龙-11在高温下具有优异的压电性能，但在过去几十年中对其研究较少。为了将尼龙-11用于未来的传感器或振动能量收集装置，控制电活性δ'晶相的形成非常重要。在这项工作中，首先通过溶液浇铸制备尼龙-11薄膜，然后在不同的拉伸比（SR）和温度（T）下进行单轴拉伸，以获得一系列拉伸薄膜。二维广角X射线衍射（2D-WAXD）和差示扫描量热法（DSC）技术的结合表明，δ'晶相的比例随拉伸比增加，并在80°C的温度下达到最大值。此外，发现所制备的尼龙-11薄膜的铁电和压电性能与其晶体结构密切相关。因此，在300%的拉伸比和80°C的温度下拉伸的尼龙-11薄膜表现出最大剩余极化和7.2 pC/N的显著压电系数。用这种尼龙-11薄膜制成了一个简单的压电器件，该器件可分别产生1.5 V的输出电压和11 nA的电流。
