MXene/ carbon black /polyimide aerogels: Integrating microwave absorption, thermal stability, flame retardancy, and hydrophobicity

The electromagnetic absorption properties of single optimized wave-absorbing materials limit their practical applications in complex environments such as aerospace and military protection. Therefore, it is of great significance to develop composite materials that combine high temperature resistance, flame retardancy and other properties with efficient wave-absorbing properties. In this study, MXene/CB/PI (MCP) aerogels were successfully prepared by using polyimide (PI) as the polymer matrix and carbon black (CB) and MXene as the conductive fillers. The porous structure of the aerogel enhances the multiple reflections and propagation path length of electromagnetic waves. The conductive network facilitates the conversion of electromagnetic waves into electric currents for efficient conductive loss and multiple heterogeneous interfaces enhance the interfacial polarization. Therefore, the prepared MCP aerogel has excellent microwave absorption properties, with a minimum reflection loss (RL_min) of −56.3 dB and an effective absorption bandwidth (EAB) that completely covers the X-band (4.2 GHz). In addition, MCP aerogel also exhibits: excellent thermal stability (Weight loss is only noticeable above 520 °C), good flame retardancy (LOI up to 43.7 %) and good hydrophobicity (water contact angle of about 110°). MCP aerogel materials combine multiple functions and are expected to play an important role in aerospace and other fields.