High-performance flexible microwave-absorbing MXene/polydimethylsiloxane composites with highly oriented functionalized filler networks at low MXene content

Abstract

Obtaining highly flexible microwave-absorbing materials with good mechanical and absorption properties at low filler contents are greatly challenging. In this research, we prepared amphiphilic CSMXene/polydimethylsiloxane (PDMS) composite with oriented CSMXene sheets by the Pickering emulsion template. The brick-mud-brick sandwich structure was formed in the CSMXene/PDMS composites. This special structure built orientated networks at low MXene contents and enhanced multiple electromagnetic-wave reflections between adjacent MXene sheets. The results showed that the CSMXene/PDMS composite with orientated CSMXene had a good absorption performance in a wide frequency range (2–18 GHz), and exhibited an effective absorption bandwidth (EAB) of 4.3 GHz at 1.7 mm when the CSMXene content was only 4.72 wt%, and the minimum reflection loss (RLmin) of − 49.95 dB at 3.5 mm when the CSMXene content was only 6.48 wt%. Compared with those of the MXene/PDMS composite with un-oriented MXene sheets, the RLmin, elongation at break and tensile strength of CSMXene/PDMS composite with orientated CSMXene sheets were superior by 397%, 280% and by 245%, respectively. Strikingly, the EAB also improved from 0.06 to 4.3 GHz. These results showed high-performance flexible microwave-absorbing MXene/polydimethylsiloxane composites could be obtained at a low MXene content in the presence of highly oriented functionalized filler networks in PDMS.