Tsyganov Alexey, Vikulova Maria, Zotov Ilya, Grapenko Olga, Vlasenko Valery, Bainyashev Alexey, Gorokhovsky Alexander, Gorshkov Nikolay
Department of Chemistry and Technology of Materials, Yuri Gagarin State Technical University of Saratov, 77 Polytecnicheskaya Street, 410054 Saratov, Russia.
Research Institute of Physics, Southern Federal University, 194 Stachki Avenue, 344090, Rostov-on-Don, Russia.
Nanoscale. 2024 Aug 15;16(32):15208-15218. doi: 10.1039/d4nr01612b.
In this study, two-dimensional VCT MXenes were prepared by an accessible and rapid method, which involved aluminothermic combustion synthesis of the VAlC MAX phase and its further processing in an HCl/LiF mixture under hydrothermal conditions. The resulting VCT MXene was characterised by XRD, SEM, TEM and XANES. A colloidal solution of the VCT MXene in dimethylformamide was used to prepare nanocomposites based on a poly(vinylidene fluoride) polymer matrix with a conductive filler content of 2.5 to 20 wt%. The nanocomposites were characterised by XRD, SEM and simultaneous DSC-TG analysis. The dielectric properties of the nanocomposites were studied using impedance spectroscopy in the frequency range from 100 Hz to 1 MHz at temperatures from -50 to +140 °C. The results showed that adding 20 wt% VCT to PVDF allows increasing the permittivity to 425.3 with a dielectric loss tangent of 0.54 at a frequency of 10 kHz. Studies of the temperature behavior of the dielectric response of composites have shown that the nature of the temperature dependence of the permittivity and dielectric loss tangent was determined mainly by the characteristics of the PVDF polymer matrix, while the filler had a significant effect only on the interfacial polarization, which increased with increasing VCT filler concentration and temperature.
在本研究中，通过一种简便快速的方法制备了二维VCT MXene，该方法包括VAlC MAX相的铝热燃烧合成及其在水热条件下于HCl/LiF混合物中的进一步处理。所得的VCT MXene通过XRD、SEM、TEM和XANES进行表征。将VCT MXene在二甲基甲酰胺中的胶体溶液用于制备基于聚偏二氟乙烯聚合物基体的纳米复合材料，其中导电填料含量为2.5至20 wt%。通过XRD、SEM和同步DSC-TG分析对纳米复合材料进行表征。在-50至+140°C的温度范围内，使用阻抗谱在100 Hz至1 MHz的频率范围内研究了纳米复合材料的介电性能。结果表明，在PVDF中添加20 wt%的VCT可使介电常数在10 kHz频率下提高到425.3，介电损耗正切为0.54。对复合材料介电响应的温度行为研究表明，介电常数和介电损耗正切的温度依赖性本质主要由PVDF聚合物基体的特性决定，而填料仅对界面极化有显著影响，界面极化随VCT填料浓度和温度的升高而增加。
