Introduction to the results
High-performance lightweight carbon aerogel (CA) has received widespread attention in the fields of electrochemical , catalysis, adsorption, energy storage, etc. However, finding an environmentally friendly and efficient preparation method and achieving controllable performance of CA remains a challenge. This article, Sichuan University Huawei Zou, Pengbo Liu and other researchers published a paper titled "Anisotropic and Lightweight Carbon/Graphene Composite Aerogels for Efficient Thermal Insulation and Electromagnetic Interference Shielding" in the journal of the "ACS Appl. Mater. Interfaces". study proposed to synthesize a series of anisotropic carbon/graphene composite aerogels by unidirectional freezing of polyacid ammonium salt/graphene oxide (PAS/GO) suspension, then freeze-drying, thermal imidation and carbonization.
aerogel prepared in showed a tubular pore structure along the freezing direction. GO dispersed in the polymer matrix enhances the aerogel's backbone, thereby significantly inhibiting volume shrinkage during preparation, thus providing a low density of 0.074–0.185 g cm–3. In addition, the orientation pore structure gives the composite aerogel obvious anisotropic thermal insulation properties. When the density is 0.074 g cm–3, the radial thermal conductivity is as low as 0.038 W m–1 K–1. When the initial content of GO rises to 20 phr, the resulting aerogel exhibits a high conductivity of about 0.77 S cm–1 in the radial direction, and at the same time, the electromagnetic interference shielding effect (EMI SE) reaches 54.6 dB. Therefore, this study provides a simple and environmentally friendly method for the preparation of lightweight anisotropic carbon aerogels.
Graphics and text introduction
Figure 1. Schematic diagram of CG aerogel preparation.
Figure 2. Volume shrinkage, weight loss during carbonization, and relationship between density and GO content of carbon/graphene composite aerogel.
Figure 3 (a-b) Full scan XPS spectra and C1s spectra of PI/rGO-10 and CG-10. (C-d) XRD mode and Raman spectra of rGO-800 and CG aerogels with different GO contents.
Figure 4. Thermal properties of carbon/graphene composite aerogel
Figure 5. Electromagnetic interference shielding performance of carbon/graphene composite aerogel
summary
In summary, this paper successfully prepared a series of carbon/graphene composite aerogels with anisotropic structures through unidirectional freeze-drying, thermal imidation and carbonization processes. This material has simple preparation technology and excellent performance, and has broad application prospects in thermal insulation and electromagnetic shielding materials.
Literature:
https://doi.org/10.1021/acsami.2c13000
