Controlled growth of polyaniline nanofibers on the surface of alkali pre-treated PI fabric as electromagnetic wave-absorbing fabrics

The electromagnetic wave attenuation network composed of PANI NFs is an efficient wave-absorbing structure. Constructing PANI NFs networks on the surface of flexible fabrics is a potential approach to improve the wave-absorbing properties of fabrics, but there are few related reports on this. In this paper, we proposed a facile method to grow PANI NFs (average diameter of 80-100 nm) on the polyimide (PI) fabric surface through a controlled nucleation and growth process. The results of FESEM, FTIR, XPS, and UV-vis indicated that the PANI and PI may first combine at the initial nucleation centers through electrostatic interactions, hydrogen bonding, and π-π stacking, and then the PANI grows linearly into elongated nanofibers under suitable polymerization conditions. As expected, the PANI NFs coated fabric achieved a strong reflection loss (RL) of -34.20dB (>99.999% absorption) and a broad effective absorption frequency band of 5-18 GHz. The excellent absorption performance originated from the conduction loss, scattering loss, and polarization relaxation loss of the PANI NFs network. In addition, the fabric exhibits good thermal stability (Td beyond 570°C) and long-term stability ((90.57% retention of conductivity after 500 bending cycles). This study provides a viable approach for designing next-generation microwave-absorbing fabric.