Alam Rabeya Binta, Ahmad Md Hasive, Islam Muhammad Rakibul
Department of Physics, Bangladesh University of Engineering and Technology (BUET) Dhaka Bangladesh
RSC Adv. 2022 May 16;12(23):14686-14697. doi: 10.1039/d2ra01508k. eCollection 2022 May 12.
In this work, multi wall carbon nanotube (MWCNT) reinforced bio-derived gelatin-based polymer nanocomposites were synthesized following an easy and affordable solution-casting method. The effects of different concentrations of MWCNTs on the structural, surface morphological, and dielectric properties of the nanocomposites were studied. A four-fold increase in the dielectric constant is observed due to the incorporation of just 0.02 wt% of MWCNT nanofiller into the polymer matrix. The modified Cole-Cole model was used to analyze the effect of nanofiller concentrations on the different dielectric parameters of the nanocomposite. The incorporation of MWCNTs was found to increase the dielectric strength and reduce the relaxation time of the nanocomposite. The AC conductivity of the nanocomposites was found to be improved due to the incorporation of the MWCNT nanofiller. A quantitative study based on the simulation of the complex impedance spectra demonstrates that the addition of MWCNTs into the nanocomposite decreases the grain barrier resistance from 5935 kΩ to 261 kΩ and increases the capacitive component from 0 to 23.25 μF. The improved dielectric performance of the nanocomposites can be attributed to the space charge polarization effect and is illustrated with a charge transport mechanism model. This biopolymer-based nanocomposite material with a large dielectric constant together with a small loss tangent may offer a potential route for the fabrication of fully biocompatible electrostatic capacitors and energy storage devices.
在本工作中，采用简便且经济的溶液浇铸法合成了多壁碳纳米管（MWCNT）增强的生物衍生明胶基聚合物纳米复合材料。研究了不同浓度的MWCNT对纳米复合材料的结构、表面形态和介电性能的影响。由于仅向聚合物基体中加入0.02 wt%的MWCNT纳米填料，观察到介电常数增加了四倍。采用修正的Cole-Cole模型分析了纳米填料浓度对纳米复合材料不同介电参数的影响。发现加入MWCNT可提高纳米复合材料的介电强度并缩短其弛豫时间。由于加入了MWCNT纳米填料，纳米复合材料的交流电导率得到改善。基于复阻抗谱模拟的定量研究表明，向纳米复合材料中添加MWCNT可使晶界电阻从5935 kΩ降至261 kΩ，并使电容性分量从0增加到23.25 μF。纳米复合材料介电性能的改善可归因于空间电荷极化效应，并通过电荷传输机制模型进行了说明。这种具有大介电常数和小损耗角正切的生物聚合物基纳米复合材料可能为制备完全生物相容的静电电容器和储能装置提供一条潜在途径。
