Manika Georgia C, Gioti Sevasti, Sanida Aikaterini, Mathioudakis Georgios N, Abazi Anxhela, Speliotis Thanassis, Patsidis Anastasios C, Psarras Georgios C
Smart Materials & Nanodielectrics Laboratory, Department of Materials Science, School of Natural Sciences, University of Patras, 26504 Patras, Greece.
Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research & Technology-Hellas (FORTH), Stadiou Str., Platani, 26504 Patras, Greece.
Polymers (Basel). 2022 Nov 9;14(22):4817. doi: 10.3390/polym14224817.
Polymer matrix nanocomposites are widely studied because of the versatility of their physical and mechanical properties. When these properties are present simultaneously, responding at relative stimuli, multifunctional performance is achieved. In this study, hybrid nanocomposites of SrFeO and BaTiO ceramic particles dispersed in an epoxy resin matrix were fabricated and characterized. The content of SrFeO was varying, while the amount of BaTiO was kept constant. The successful fabrication of the nanocomposites and the fine dispersion of the ceramic particles was verified via the morphological and structural characterization carried out with X-ray Diffraction patterns and Scanning Electron Microscopy images. Dielectric response and related relaxation phenomena were studied by means of Broadband Dielectric Spectroscopy. Dielectric permittivity augments with filler content, while the recorded relaxations, with descending relaxation time, are: (i) interfacial polarization, (ii) glass-to-rubber transition, (iii) intermediate dipolar effect, and (iv) re-orientation of polar-side groups of the main polymer chain. SrFeO nanoparticles induce magnetic properties to the nanocomposites, which alter with the magnetic filler content. Static and dynamic mechanical response improves with filler content. Thermogravimetric analysis shown that ceramic particles are beneficial to the nanocomposites' thermal stability. Glass transition temperature, determined via Differential Scanning Calorimetry, was found to slightly vary with filler content, in accordance with the results from dynamic mechanical and dielectric analysis, indicating the effect of interactions occurring between the constituents. Examined systems are suitable for energy storing/retrieving.
聚合物基纳米复合材料因其物理和机械性能的多功能性而受到广泛研究。当这些性能同时存在并对相关刺激做出响应时,就实现了多功能性能。在本研究中,制备并表征了分散在环氧树脂基体中的SrFeO和BaTiO陶瓷颗粒的混合纳米复合材料。SrFeO的含量变化,而BaTiO的量保持恒定。通过X射线衍射图谱和扫描电子显微镜图像进行的形态和结构表征,验证了纳米复合材料的成功制备以及陶瓷颗粒的良好分散。通过宽带介电谱研究了介电响应和相关的弛豫现象。介电常数随填料含量增加,而记录到的弛豫现象,弛豫时间递减,依次为:(i)界面极化,(ii)玻璃态到橡胶态转变,(iii)中间偶极效应,以及(iv)主聚合物链极性侧基团的重新取向。SrFeO纳米颗粒赋予纳米复合材料磁性,该磁性随磁性填料含量而变化。静态和动态力学响应随填料含量提高。热重分析表明陶瓷颗粒有利于纳米复合材料的热稳定性。通过差示扫描量热法测定的玻璃化转变温度,发现随填料含量略有变化,这与动态力学和介电分析的结果一致,表明各组分之间发生相互作用的影响。所研究的体系适用于能量存储/回收。