ABSTRACT

In flexible electronics, a highly electroconductive, flexible, and durable material is important for various applications. This study describes the property changes in graphene nanosheets (GNSs) doped into a conductive silver (Ag) paste that is used to form a grid-style pattern on a polyurethane hot melt film (PU HMF) for electromagnetic wave shielding. Electrical conductivity, thermal conductivity, and bending tests were performed for materials fabricated by an electronic printing method. The results showed that the conductive paste with a loading of 0.3 wt% GNSs (3SC) had good electromagnetic shielding effectiveness (EMSE, 49.9 dB at 1800 MHz), much better electrical conductivity (4.63*10⁴ S/cm) than the pure silver paste (1.38*10⁴ S/cm), and an improved bending ability. The coefficient of variation of GNS loading (3.01% to 3.80%) under 1000 cyclic bending tests was better than that of the pure silver paste (6.94%) at 2.4% strain, but the results under 500 cyclic elongation tests at 10.0% strain did not exhibit the same pattern. The coefficients of variation (CVs) of all samples in the GNS group (8.3–13.3%) were worse than those of the pure silver group (6.3%) after the elongation test. The reason for the differences in the electrical conductivity and flexibility was explained by the SEM results, which indicated notable damage after the bending and elongation tests. Woven fabrics laminated with a PU/Ag/GNS conductive film that were doped with different amounts of fillers were successfully manufactured by electronic printing and can be used for Electromagnetic Interference (EMI) shielding materials, electrodes for sensor components, wearable elements, smart home textiles, and conductive materials, for example.

摘要

在柔性电子产品中，高导电性、柔性和耐用材料对各种应用都很重要。本研究描述了掺杂到导电银 (Ag) 糊中的石墨烯纳米片 (GNS) 的特性变化，该糊用于在聚氨酯热熔膜 (PU HMF) 上形成网格样式的图案以进行电磁波屏蔽。对通过电子印刷方法制造的材料进行了导电性、导热性和弯曲测试。结果表明，负载量为 0.3 wt% GNSs (3SC) 的导电浆料具有良好的电磁屏蔽效果（EMSE，1800 MHz 时为 49.9 dB），比纯银导电浆料具有更好的导电性（4.63*10 ⁴ S/cm）。粘贴（1.38*10 ⁴S/cm)，以及改进的弯曲能力。1000次循环弯曲试验下GNS负载的变异系数（3.01%~3.80%）优于2.4%应变下的纯银浆（6.94%），但10.0%应变下500次循环伸长率试验下的结果不表现出相同的模式。伸长率试验后，GNS 组所有样品的变异系数（CV）（8.3-13.3%）均比纯银组（6.3%）差。SEM 结果解释了导电性和柔韧性差异的原因，这表明在弯曲和伸长率测试后有明显的损坏。