Ultralight reduced graphene oxide based foam with excellent electromagnetic interference shielding and superior mechanical properties

Reduced graphene oxide/carboxymethyl cellulose (RGO/CMC) foams with ultra-lightweight, excellent EMI shielding and mechanical robustness are fabricated based on a facile solution method and regulation of thermal reduction conditions. Results indicate that the two-step heating mode is good to obtain better EMI shielding properties. By introducing only 10 wt% of CMC, high electrical conductivity up to 34.7 S/m and EMI shieling effectiveness (SE) up to 34.6 dB are obtained. In addition, due to the connection effect of CMC, superior compressive strength and modulus as high as 8.3 KPa and 29.2 KPa are achieved, corresponding to an increase of 388.2% and 378.7%, respectively, compared to that of the RGO foam without CMC. Moreover, due to the ultralow density (∼4.1 mg/cm3) and high EMI SE of RGO/CMC, excellent specific shielding efficiency as high as 42195 dB.cm2/g is obtained, way much superior to that of other metal-, graphene-, and CNT-based carbon foams. This work will have great significance for facile fabricating efficient EMI shielding materials towards electronics and aerospace applications.