Abstract This paper investigates the properties of the polyaniline (PANI) on açaí vegetable fiber (AVF), hereafter referred to as PANI-COATED:AVF. Scanning electron and atomic force microscopy showed that the incorporation of PANI produced a linear surface, while optical microscopy images showed that the semiconductor layer was flawed. The complex impedance measurements performed at room temperature indicated that the electrical properties of PANI were fully transferred to the PANI-COATED:AVF and that the Cole-Cole approach dominated over a frequency range from 1 Hz to 100 kHz. Thermogravimetric analysis revealed a thermal stability range of 0° to 300°C. Finally, the combination of PANI with AVF was a successful due to the ease of processing and obtaining semiconductor filaments with wide ranges of thermal and electrical stability. This article is a complement to another recently published [doi.org/10.1002/pc.27068].

In this work we investigated the effect of visible radiation on the electrical properties of poly[(2-methoxy-5-hexyloxy)-p-phenylenevinylene]- MH-PPV films and light emitting diodes. Complex impedance measurements of (Au or ITO)/MH-PPV/(Au or Al) samples were carried out at room temperature and exposed to white light. Over the frequency range from 100 mHz to 2 MHz, the electrical results of Au/MH-PPV/Au was dominated by the Cole-Cole approach, where the electrode influence is negligible. However, some additional influence of the interface was observed to occur when Al was used as electrode. These effects were observed under both dark and visible-light illumination conditions. A simple model based on resistor-capacitor parallel circuits was developed to represent the complex impedance of the samples, thereby separating bulk and interface contributions. We observed that the polymer electrical resistivity decreased while the dielectric constant of the polymer and the thickness of the Al/MH-PPV layer were almost constant with increasing light intensity. The decrease of the polymer layer resistance comes from a better charge injection due to a light induced dissociation of positive charge carriers at the electrode.