[Journal of Materials Science & Technology] Lightweight and robust rGO/sugarcane derived hybrid carbon foams with outstanding EMI shielding performance
作者：Lei Wang#, Xuetao Shi#, Junliang Zhang, Yali Zhang and Junwei Gu*
关键字：electromagnetic interference shielding effectiveness, electromagnetic interference shielding effectiveness, graphene oxide
论文来源：期刊
具体来源：Journal of Materials Science & Technology
发表时间：2020年
Abstract: Increasingly severe electromagnetic pollution is now in urgent need of materials with lightweight, excellent flame retardancy, and outstanding electromagnetic interference shielding effectiveness (EMI SE). Renewable source-derived carbon foams and graphene have attracted extensive attention due to their 3D porous structure and remarkable electrical conductivity (σ). In this work, annealed sugarcane (ASC) was prepared by removal of lignin from sugarcane via hydrothermal reaction, followed by annealing treatment. Then graphene oxide (GO) was filled by vacuum-assisted impregnation process and thermally annealed to obtain the ASC/reduced graphene oxide (rGO) hybrid foams. When the loading of rGO is 17 wt.%, the ASC/rGO hybrid foam (density, ρ of 0.047 g/cm3) exhibits the optimal σ of 6.0 S/cm, EMI SE of 53 dB, specific SE (SSE = SE/ρ)/thickness (t) of 3830 dB·cm2/g, and compressive strength of 1.33 MPa, which is 76 %, 36 %, 13 % and 6 % higher than those of ASC, respectively. Moreover, ASC/rGO presents excellent flame retardancy, thermal stability, and heat insulation, which remains constant under burning on an alcohol lamp and presents low thermal conductivity of 115.19?mW/(m·K), close to the requirement for heat insulation. Synergistic effect of ASC and rGO not only significantly increase σ of ASC/rGO, but fully utilizes the capability of ASC and rGO to attenuate electromagnetic waves by virtue of unique porous structures and abundant interfaces. Such kind of lightweight EMI materials with excellent mechanical property, shielding performance, flame retardancy, and heat insulation is expected to tackle the key scientific and technical bottleneck problems of EMI materials, and will greatly expand the application of carbon nanomaterials in the field of aerospace industry.
随着日益严重的电磁污染，低密度和高屏蔽效能的屏蔽材料的研发已变得尤为重要。受甘蔗的有序多孔结构启发，通过水热反应去除甘蔗中的木质素获得水热处理的甘蔗（SCHT）后将其退火，并借助真空辅助浸渍工艺填充氧化石墨烯后进一步热还原，制备出轻质和高导电的退火甘蔗（ASC）/rGO杂化泡沫。当石墨烯的用量为17wt%时，ASC/rGO-3的密度仅为0.047g/cm3，展现出最大的压缩强度、电导率、屏蔽效能和比效能/厚度，分别为1.33 MPa、6.04 S/cm-1、53 dB和3830 dB·cm2/g。并且，ASC/rGO-3还具有优异的阻燃性能、热稳定性和隔热性能，能够在酒精灯灼烧下无变化和接近于绝热要求的热导率（115.2 mW/(m·K)）。独特的有序多孔结构和丰富的界面增强了ASC/rGO-3对电磁波的损耗能力，屏蔽机理主要以吸收为主。这种轻质，具有优异的力学性能、屏蔽性能、阻燃性能力和隔热性能的屏蔽材料将极大地拓展碳纳米材料在航空航天工业中的应用。