Reduced graphene oxide/cyanoethyl cellulose composite: An example of dielectric tailoring design for efficient microwave absorption materials

Nowadays, electromagnetic pollution is becoming increasingly severe, causing disturbances to electronic devices and posing a potential threat to human health. Therefore, there is an urgent demand for lightweight and efficient electromagnetic wave absorbing (EMA) materials. Our study proposes a dielectric regulation idea to create graphene/polymer efficient electromagnetic wave absorbers. Cyanoethyl cellulose (CEC) with high dielectric real part (epsilon') and low dielectric imaginary part (epsilon") is used as the matrix to composite with high -epsilon' and high -epsilon" reduced graphene oxides (rGO). The interwoven long fibers of CEC provide a framework for rGO attachment, allowing the fabrication of the 3D rGO structure that suppresses graphene stacking and improves the dispersibility of rGO. Beneficial from these advantages, a small addition of rGO makes the rGO/CEC composites acquire high e' and appropriate e", which are essential for impedance matching and efficient EMA performance. As a result, the rGO/CEC with only 0.7 wt% rGO achieves the minimum reflection loss (RLmin) of -42.8 dB at 10.6 GHz with the effective absorption bandwidth (RL < -10 dB) spanning 3.6 GHz. This work demonstrates an effective material -design strategy for developing efficient EMA materials through dielectric regulation, which opens up a new dimension for advanced EMA materials design.