Carbonized foams from graphene/phenolic resin composite aerogels for superior electromagnetic wave absorbers. Issue 18 (15th September 2021)

• Record Type: Journal Article
• Authors: Li, Jinhuan; Ji, Huanmin; Li, Andong; Zhang, Jiaojiao; Yan, Yi; Ren, Linlin; Yu, Hongyan
• Is Part Of: Ceramics international. Volume 47:Issue 18(2021)
• Page Start: 26082
• Page End: 26091
• Publication Date: 2021-09-15
• Subjects: Graphene/phenolic resin composite foam -- Carbonization -- Electromagnetic wave absorption -- Thermal stability -- Corrosion resistance; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.06.014
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Ultralight graphene/phenolic resin composite aerogels (GPFs) were prepared through the chemical reduction and self-assembly of graphene oxide (GO) in water-soluble phenolic resin, followed by a freeze-drying process; carbonized foams (GPFs(T)) were obtained by the subsequent heat treatment of GPFs at a relatively low temperature (500–700 °C). Although GPFs do not show the qualified reflection loss value of below −10dB, GPFs(T) achieve the greatly enhanced electromagnetic-wave absorbing performance. Specifically, the minimum reflection loss value of GPF1 (500) reaches −22.7 dB at 14.4 GHz with the absorber thickness of 2.0 mm and the effective absorption bandwidth is up to 5.4 GHz (12.4–17.8 GHz). The evolution of electromagnetic-wave absorbing properties from GPFs to GPFs(T) at different temperatures related with different graphene content is explored. GPFs(T) are expected to exhibit high thermal stability and excellent corrosion resistance property, and especially still maintain ultralight nature (e.g the density of GPF1 (500) is only 24.3 mg/cm 3 ). Most importantly, little graphene (as low as 7.5 wt% of GO addition for GPF1 (T)) in GPFs(T) guarantees the facile formation of three-dimension (3D) skeleton network and greatly cut downs the carbonization temperature of phenolic resin to achieve the required electromagnetic-wave energy losing ability. The present work provides an effective method to fabricate an ultralight material with exceptional performances including the good electromagnetic-wave absorbing property and the high stability.