Development of a Short Carbon Fiber@Polyaniline/Polydimethylsiloxane Flexible Composite Film with Excellent Microwave Absorption Properties at an Ultralow Filler Content

In this work, a flexible composite film was prepared by a facile mechanical mixing method with polydimethylsiloxane as the matrix and short carbon fiber@polyaniline as the microwave absorption (MA) functional filler. The prepared short carbon fiber@polyaniline/polydimethylsiloxane (SCF@PANI/PDMS) composite film has excellent mechanical properties as well as outstanding MA properties. When the added filler content is 2 wt %, the optimal comprehensive tensile strength and the elongation at break of the SCF@PANI/PDMS specimens reach 3.43 ± 0.14 MPa and 180.82 ± 6.84%, respectively. Simultaneously, the corresponding bandwidth and reflection loss of the SCF@PANI/PDMS at a thickness of 2.04 mm reach 4.48 GHz (9.54–14.02 GHz) and −52.22 dB (10.73 GHz), respectively. The excellent MA performance of SCF@PANI/PDMS is attributed to the good impedance matching characteristics resulting from the coordinated electromagnetic properties and the inherent strong attenuation capability of the material. This work provides an idea for the facile design of flexible high-performance MA materials that can be developed as a promising candidate for practical applications.