Anisotropic microcellular epoxy/rGO-SCF aerogel foam with excellent compressibility and superior electromagnetic interference shielding performance. (10th November 2022)

• Record Type: Journal Article
• Authors: Fan, Xun; Gao, Qiang; Zhang, Yu; Qin, Jianbin; Zhao, Yongsheng; Shi, Xuetao; Zhang, Guangcheng
• Is Part Of: Composites science and technology. Volume 230(2022)Part 1
• Publication Date: 2022-11-10
• Subjects: Hybrid carbon aerogel -- Supercritical CO2 foaming method -- Microcellular epoxy-based nanocomposite -- Electromagnetic interference shielding effectiveness; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2022.109718
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Carbon aerogel shows great potential in electromagnetic interference shielding (EMI) application and is generally strengthened by epoxy impregnation for harsh working environment. However, it is still challenging to simultaneously achieve high mechanical robustness and EMI performance, especially taking low-cost and light-weight feature into account. In this work, a "gelation-press drying-impregnation & micro-foaming" method was systematically reported to target microcellular epoxy foam containing hybrid reduced graphene oxide (rGO)/short-carbon-fiber (SCF) aerogel. Herein, aerogel morphology was transformed from isotropic honey-comb structure into anisotropic corrugated structure by controllable press air-drying. A further supercritical carbon dioxide (scCO2 ) foaming process was implemented for density reduction. Moreover, the anisotropic microcellular epoxy(m-EP)/rGO-SCF foam (D = ∼0.48 μm, N f = 5.02 × 10 12 cell/cm 3 ) shows low density (1.14 g/cm 3 ), high electrical conductivity (2365.0 S/m), enhanced compressibility (σb = 243.0 MPa, εb = ∼45%) and outstanding EMI shielding effectiveness (95.5 dB) with a low thickness (2.0 mm) within X band (8.2–12.4 GHz). Therefore, our work provides a universal step-by-step and industrial-friendly approach to fabricate light-weight carbon-aerogel-based foams with anisotropic carbon structure and outstanding EMI performance. Graphical abstract: Image 1 Highlights: A "gelation-press drying-impregnation & micro-foaming" method systematically reported to target microcellular m-EP/rGO-SCF composites. Aerogel morphology transformed from isotropic honey-comb structure into anisotropic corrugated structure by controllable press air-drying. scCO2 foaming process implemented for density reduction. Nanocomposite with comprehensive properties including low density (1.14 g/cm 3 ), high electrical conductivity (2365.0 S/m), enhanced compressibility (σb = 243.0 MPa, εb = ∼45%) and outstanding EMI performance (95.5 dB). Comprehensive properties including low density, enhanced compressibility, high electrical conductivity and outstanding EMI performance.