Preparation of a superior intense, lightweight, affordable, broadband microwave-absorbing nanocomposite by PUF/PANi

Abstract

In this study, a simple, lightweight, and broadband microwave-absorbing nanocomposite was prepared. Accordingly, a doped polyaniline (PANi) was quickly synthesized with a modified sonochemical technique and then composited with a polyurethane foam (PUF). The PANi nanostructure and the PUF/PANi nanocomposite were characterized using the diffuse reflection spectroscopy (DRS), vector network analyzer (VNA), Fourier transform infrared (FT-IR), elemental mapping analysis, field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), four-point probe conductometer (FPPC), and x-ray powder diffraction (XRD) analysis. All the results confirmed that the PANi nanostructure was prepared with the appropriate size and crystalline structure as well as a high electrical conductivity (449.51 S cm−1). The applied methods led to preparation of PANi/PUF nanocomposite due to their chemical coupling as well as electrostatic interactions including π–π stacking. According to the VNA results, the PUF absorbed a bandwidth greater than the x and ku-band>10 dB, while its maximum reflection loss was −58.76 dB at 13.18 GHz with a thickness of 2.8 mm. The foam absorbed 89.80 dB of microwaves at 9.21 GHz with 4.0 mm in thickness, while the maximum reflection loss of the PUF/PANi 50 wt% was 84.90 dB at 10.22 GHz with a 5.1 GHz bandwidth >10 dB and a thickness of 3.5 mm. The composite absorbed 69.20 dB at 13.86 GHz at 2.5 mm thickness and absorbed 9.35 GHz >10 dB along the 8.2–18 GHz.