Prokhorov Evgen, Luna-Bárcenas Gabriel, Yáñez Limón José Martín, Gómez Sánchez Alejandro, Kovalenko Yuriy
Cinvestav, Unidad Querétaro, Querétaro 76230, QRO, Mexico.
Postgraduate Department, University of Aeronautics of Querétaro, Querétaro 76278, QRO, Mexico.
Polymers (Basel). 2020 Sep 1;12(9):1991. doi: 10.3390/polym12091991.
The aim of this work is to structurally characterize chitosan-zinc oxide nanoparticles (CS-ZnO NPs) films in a wide range of NPs concentration (0-20 wt.%). Dielectric, conductivity, mechanical, and piezoelectric properties are assessed by using thermogravimetry, FTIR, XRD, mechanical, and dielectric spectroscopy measurements. These analyses reveal that the dielectric constant, Young's modulus, and piezoelectric constant (d) exhibit a strong dependence on nanoparticle concentration such that maximum values of referred properties are obtained at 15 wt.% of ZnO NPs. The piezoelectric coefficient d in CS-ZnO nanocomposite films with 15 wt.% of NPs (d = 65.9 ) is higher than most of polymer-ZnO nanocomposites because of the synergistic effect of piezoelectricity of NPs, elastic properties of CS, and optimum NPs concentration. A three-phase model is used to include the chitosan matrix, ZnO NPs, and interfacial layer with dielectric constant higher than that of neat chitosan and ZnO. This layer between nanoparticles and matrix is due to strong interactions between chitosan's side groups with ZnO NPs. The understanding of nanoscale properties of CS-ZnO nanocomposites is important in the development of biocompatible sensors, actuators, nanogenerators for flexible electronics and biomedical applications.
这项工作的目的是在广泛的纳米颗粒浓度范围（0-20重量%）内对壳聚糖-氧化锌纳米颗粒（CS-ZnO NPs）薄膜进行结构表征。通过热重分析、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、力学和介电谱测量来评估介电、导电、力学和压电性能。这些分析表明，介电常数、杨氏模量和压电常数（d）对纳米颗粒浓度有很强的依赖性，使得在ZnO NPs含量为15重量%时获得了上述性能的最大值。由于纳米颗粒的压电性、壳聚糖的弹性性能以及最佳纳米颗粒浓度的协同效应，含有15重量%纳米颗粒的CS-ZnO纳米复合薄膜中的压电系数d（d = 65.9）高于大多数聚合物-ZnO纳米复合材料。采用三相模型来包含壳聚糖基体、ZnO NPs以及介电常数高于纯壳聚糖和ZnO的界面层。纳米颗粒与基体之间的这一层是由于壳聚糖侧基与ZnO NPs之间的强相互作用。了解CS-ZnO纳米复合材料的纳米级性能对于开发用于柔性电子和生物医学应用的生物相容性传感器、致动器、纳米发电机至关重要。
