Abstract A new type of graphene@poly(dopamine)-Ag (Gns@PDA-Ag) core-shell nanoplatelets was designed to improve the dielectric properties of thermoplastic polyurethane (TPU) composites. The microstructure, dielectric performances and the effects of Ag nanoparticles’ content on the dielectric properties of composites were investigated. Results showed that the addition of Gns@PDA-Ag nanoplatelets could effectively improve the dielectric constant of the composite. When tested at low frequency (below 100 Hz), the highest dielectric constant of the TPU/Gns@PDA-0.78Ag (3 wt%) composite was 118.82, which was 14 times higher than that of pure TPU (8.39). This increase in dielectric constant should be attributed to the strong polarization effect of conductive graphene nanoflakes (Gns) and Ag nanoparticles to TPU molecules. The PDA shell could prevent direct contact between Gns and Ag nanoparticles, limit the formation of conductive pathways, which kept the dielectric loss of the composites at a low level and maintained the breakdown strength in a stable state. Compared with pure TPU (0.29), the minimum dielectric loss of composites was only 0.36. Moreover, after Gns@PDA-Ag nanoplatelets with higher Ag content were doped into TPU, the composite showed a higher dielectric constant, and due to the existence of the Coulomb blocking effect, the dielectric loss did not increase significantly. The scalability and simplicity of the described method will provide a promising route to polymer composites for highspeed integrated circuits and energy storage applications.

中文翻译：

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以石墨烯@聚（多巴胺）-Ag核壳纳米片作为填料填充的TPU复合材料的介电性能增强

摘要 为了提高热塑性聚氨酯（TPU）复合材料的介电性能，设计了一种新型的石墨烯@聚（多巴胺）-Ag（Gns@PDA-Ag）核壳纳米片。研究了纳米银的微观结构、介电性能以及纳米银含量对复合材料介电性能的影响。结果表明，Gns@PDA-Ag纳米片的加入可以有效提高复合材料的介电常数。在低频（低于 100 Hz）下测试时，TPU/Gns@PDA-0.78Ag（3 wt%）复合材料的最高介电常数为 118.82，是纯 TPU（8.39）的 14 倍。这种介电常数的增加应归因于导电石墨烯纳米薄片 (Gns) 和银纳米颗粒对 TPU 分子的强极化效应。PDA外壳可以防止Gns和Ag纳米颗粒之间的直接接触，限制导电通路的形成，从而使复合材料的介电损耗保持在较低水平，并使击穿强度保持在稳定状态。与纯TPU（0.29）相比，复合材料的最小介电损耗仅为0.36。此外，将Ag含量较高的Gns@PDA-Ag纳米片掺杂到TPU中后，复合材料表现出更高的介电常数，并且由于库仑阻塞效应的存在，介电损耗没有显着增加。所描述方法的可扩展性和简单性将为用于高速集成电路和能量存储应用的聚合物复合材料提供有希望的途径。使复合材料的介电损耗保持在较低水平，并使击穿强度保持在稳定状态。与纯TPU（0.29）相比，复合材料的最小介电损耗仅为0.36。此外，将Ag含量较高的Gns@PDA-Ag纳米片掺杂到TPU中后，复合材料表现出更高的介电常数，并且由于库仑阻塞效应的存在，介电损耗没有显着增加。所描述方法的可扩展性和简单性将为用于高速集成电路和能量存储应用的聚合物复合材料提供有希望的途径。使复合材料的介电损耗保持在较低水平，并使击穿强度保持在稳定状态。与纯TPU（0.29）相比，复合材料的最小介电损耗仅为0.36。此外，将Ag含量较高的Gns@PDA-Ag纳米片掺杂到TPU中后，复合材料表现出更高的介电常数，并且由于库仑阻塞效应的存在，介电损耗没有显着增加。所描述方法的可扩展性和简单性将为用于高速集成电路和能量存储应用的聚合物复合材料提供有希望的途径。将Ag含量较高的Gns@PDA-Ag纳米片掺杂到TPU中后，复合材料表现出较高的介电常数，并且由于库仑阻塞效应的存在，介电损耗没有明显增加。所描述方法的可扩展性和简单性将为用于高速集成电路和能量存储应用的聚合物复合材料提供有希望的途径。将Ag含量较高的Gns@PDA-Ag纳米片掺杂到TPU中后，复合材料表现出较高的介电常数，并且由于库仑阻塞效应的存在，介电损耗没有明显增加。所描述方法的可扩展性和简单性将为用于高速集成电路和能量存储应用的聚合物复合材料提供有希望的途径。