Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
ACS Appl Mater Interfaces. 2023 May 24;15(20):24769-24776. doi: 10.1021/acsami.2c21994. Epub 2023 May 15.
Suspending microscale droplets of liquid metals like eutectic gallium-indium (EGaIn) in polydimethylsiloxane (PDMS) has been shown to dramatically enhance electrical permittivity without sacrificing the elasticity of the host PDMS matrix. However, increasing the dielectric constant of EGaIn-PDMS composites beyond previously reported values requires high EGaIn loading fractions (>50% by volume) that can result in substantial increases in density and loss of material integrity. In this work, we enhance permittivity without further increasing EGaIn loading by incorporating polydopamine (PDA)-coated graphene oxide (GO) and partially reduced GO. In particular, we show that the combination of EGaIn and PDA-GO within a PDMS matrix results in an elastomer composite with a high dielectric constant (∼10-57), a low dissipation factor (∼0.01), and rubber-like compliance and elasticity.
将像共晶镓铟（EGaIn）这样的微尺度液态金属液滴悬浮在聚二甲基硅氧烷（PDMS）中，已被证明可以在不牺牲宿主 PDMS 基质弹性的情况下显著提高介电常数。然而，要将 EGaIn-PDMS 复合材料的介电常数提高到之前报道的值以上，需要高的 EGaIn 负载分数（体积比超过 50%），这可能导致密度大幅增加和材料完整性丧失。在这项工作中，我们通过加入聚多巴胺（PDA）包覆的氧化石墨烯（GO）和部分还原的 GO 来提高介电常数，而不进一步增加 EGaIn 的负载。特别地，我们表明，在 PDMS 基质中同时存在 EGaIn 和 PDA-GO，可得到具有高介电常数（约 10-57）、低损耗因子（约 0.01）和橡胶状柔韧性和弹性的弹性体复合材料。
