Polypyrrole hollow tube/polyethylene geotextile composite for multifunctional protection prepared based on the soft template method of methyl orange

Herein, the application of a low-cost, multifunctional polypyrrole hollow tube composite was investigated in the building field. Firstly, polydopamine was made on the surface of a polyethylene geotextile that was the base material. Secondly, the complexes of FeCl 3 and methyl orange as soft templates were used in the in situ polymerization method to prepare a multifunctional polypyrrole hollow tube/polyethylene geotextile composite. Polydopamine played a role in improving the adhesion between the polyethylene fibers and polypyrrole hollow tubes. Finally, the electromagnetic shielding, sound absorption, piezoresistive sensing, and electrochemical properties of the composite were tested. The results showed that the shielding effectiveness value of the composite was higher than 32.7 dB in the X-band, which can shield at least 99% of electromagnetic waves. The average sound absorption coefficient value of the composite was 0.36, which was doubled compared with the polyethylene geotextile, and the peak sound absorption coefficient value reached 0.85 at the frequency of 5437 Hz. The composite could respond to deformation in the range of 4.9–99.9 kPa, and the highest sensitivity was 2.01 kPa −1 at a pressure of 14.2 kPa. The composite had an electrochemical response to KOH solutions, and the specific capacitance was 78.78 F/g at a sweep speed of 0.01 V/s. The composite had the advantages of simple preparation, low cost, and a wide range of use, and had broad application prospects in solving the increasingly severe electromagnetic interference, noise pollution, building structure nondestructive monitoring, and energy storage.