Investigation of non-covalent interactions in Polypyrrole/Polyaniline/Carbon black ternary complex for enhanced thermoelectric properties via interfacial carrier scattering and p-p stacking

The thermoelectric (TE) performance of conducting polymers can be improved by the incorporation of carbon nanomaterials. In this work, the impact of carbon black (CB) on polypyrrole (PPy) and polypyr-role/polyaniline (PPy/PANI) binary composite have been investigated. Herein, PPy/PANI binary composite was initially prepared through chemical oxidative polymerization and then solution mixed with CB to form PPy/PANI/CB ternary nanocomposite. The structural and morphological analyses confirmed the for-mation of composites, and the strong interaction present between polymer matrix and CB. This was fur-ther confirmed by theoretical study, which showed strong noncovalent interaction and high complex stability between the materials. The thermoelectric results showed that both the electrical conductivity (r) and Seebeck coefficient (S) has been increased with the increase in CB content (from 10 wt% to 30 wt %) and temperature (303 K to 373 K), while the thermal conductivity (j) increase was low. The ternary nanocomposite involving 30 wt% of CB was found to be the most promising material which showed an enhanced power factor (PF) of 0.0251 lW/mK2 and high figure of merit (ZT) of 4.37x10-5 at 370 K. The enhancement in ZT for PPy/PANI/CB ternary composite is 2 times, 316 times, 17.3 times, 3.97 times, 11.7 times, and 6.8 times greater than other samples. The enhancement in power factor and ZT was due to energy filtering effect and strong non-covalent interactions between the homopolymers and CB.(c) 2022 Published by Elsevier Inc.

Automated summary

This study confirms that the incorporation of carbon black can improve the thermoelectric performance of conducting polymers. By mixing carbon black with the polymer, the electrical conductivity and Seebeck coefficient can be increased. The ternary composite with 30 wt% carbon black exhibits the most promising properties, and the enhancement in power factor and figure of merit is attributed to the energy filtering effect and strong non-covalent interactions.