摘要
用液相还原法和水热法制备出零维和具有不同长径比的一维纳米铜。通过将其作为导电填料与聚合物P(VDF-HFP)进行溶液共混来研究填料尺寸对其聚合物基纳米复合电介质材料的介电性能及逾渗阈值的影响。利用SEM、TEM、XRD、XPS对零维及一维纳米铜的形貌、结构和化学成分进行了表征;利用SEM和阻抗分析仪分别对复合材料的结构和介电性能进行了表征,纳米铜填料在聚合物基体中分散均匀,且介电常数规律符合逾渗理论。通过线性拟合得出零维纳米铜及长径比分别为100,800的一维纳米铜的逾渗阈值分别为10.9%,6.8%,2.9%(体积分数)。与零维纳米铜和低长径比一维纳米铜相比,高长径比一维纳米铜更容易在聚合物基体中形成导电网络,从而有效地降低其复合材料的逾渗阈值,使其在较低的填充量下获得高介电常数。
Zero-dimensional (0D) copper nanoparticles and one-dimensional (1D) copper nanowires with different aspect ratios were prepared by liquid phase reduction method and hydrothermal method respectively. The nanomaterials were used as conductive fillers and mixed with P(VDF-HFP) by solution blending for investigations of the effects of filler size on the dielectric properties and percolation threshold of the polymer-based nanocomposites. The morphologies, structures and chemical compositions of the copper nanofillers were characterized by SEM, TEM, XRD and XPS. The structures and dielectric properties of the nanocomposites were characterized by SEM and impedance analysis. The copper nanofillers were uniformly dispersed in the polymer matrix and their dielectric constants were consistent with the percolation theory. The percolation thresholds of the 0D copper nanoparticles and the 1D copper nanowires with aspect ratios of 100 and 800 were 11.9%, 6.8%, and 2.8vol% respectively according to the results of linear fitting. Hence, a conductive network was easier to form in the polymer-based nanocomposite and percolation threshold of the nanocomposite was effectively reduced to obtain a high permittivity at a low filler content by adopting 1D copper nanowires with a high aspect ratio rather than 0D copper nanoparticles or 1D copper nanowires with a low aspect ratio as fillers.
作者
刘昱航
李衡峰
杨科
LIU Yuhang;LI Hengfeng;YANG Ke(School of Material science and Engineering, Central South University, Changsha 410083, China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2019年第12期12020-12025,12034,共7页
Journal of Functional Materials
基金
湖南省自然科学基金资助项目(2019JJ50818)
关键词
铜纳米粒子
铜纳米线
聚合物基复合材料
逾渗阈值
介电性能
copper nanoparticles
copper nanowires
polymer matrix composite
percolation threshold
dielectric properties
