[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*
關(guān)鍵字：electromagnetic interference shielding effectiveness, electromagnetic interference shielding effectiveness, graphene oxide
論文來源：期刊
具體來源：Journal of Materials Science & Technology
發(fā)表時(shí)間：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.
隨著日益嚴(yán)重的電磁污染，低密度和高屏蔽效能的屏蔽材料的研發(fā)已變得尤為重要。受甘蔗的有序多孔結(jié)構(gòu)啟發(fā)，通過水熱反應(yīng)去除甘蔗中的木質(zhì)素獲得水熱處理的甘蔗（SCHT）后將其退火，并借助真空輔助浸漬工藝填充氧化石墨烯后進(jìn)一步熱還原，制備出輕質(zhì)和高導(dǎo)電的退火甘蔗（ASC）/rGO雜化泡沫。當(dāng)石墨烯的用量為17wt%時(shí)，ASC/rGO-3的密度僅為0.047g/cm3，展現(xiàn)出最大的壓縮強(qiáng)度、電導(dǎo)率、屏蔽效能和比效能/厚度，分別為1.33 MPa、6.04 S/cm-1、53 dB和3830 dB·cm2/g。并且，ASC/rGO-3還具有優(yōu)異的阻燃性能、熱穩(wěn)定性和隔熱性能，能夠在酒精燈灼燒下無變化和接近于絕熱要求的熱導(dǎo)率（115.2 mW/(m·K)）。獨(dú)特的有序多孔結(jié)構(gòu)和豐富的界面增強(qiáng)了ASC/rGO-3對(duì)電磁波的損耗能力，屏蔽機(jī)理主要以吸收為主。這種輕質(zhì)，具有優(yōu)異的力學(xué)性能、屏蔽性能、阻燃性能力和隔熱性能的屏蔽材料將極大地拓展碳納米材料在航空航天工業(yè)中的應(yīng)用。