Chalcone-filled polyaniline composites for room-temperature thermoelectric applications

Abstract

The effects of the addition of 3,3 '-(1,4-phenylene)bis(1-(4-ethoxyphenyl)prop-2-en-1-one) (EtO-BCh), a chalcone derivative, on the thermoelectric (TE) characteristics of polyaniline (PANI) are investigated in this work. XRD patterns revealed that the addition of highly crystalline EtO-BCh leads to interactions that result in structural changes on the PANI backbone, and the distance between molecular layers is reduced. SEM analyses showed the high degree of homogeneity in the composite, which means a massive number of PANI/EtO-BCh interfaces, resulting in scattering low-energy carriers to boost the Seebeck coefficient. FTIR and UV-vis analyses confirmed strong molecular interactions, specifically hydrogen bonding between the carbonyl groups of EtO-BCh and the amine groups of PANI. Hall measurements demonstrated that while the addition of EtO-BCh led to a decrease in carrier concentration from 1.124 & times; 10(20) to 1.2 & times; 10(19) cm(- 3), it triggered a dramatic seven-fold increase in carrier mobility (increased from 0.98 up to 6.8 cm(2)/Vs at 5% EtO-BCh content) due to improved chain alignment. Consequently, the Seebeck coefficient saw a remarkable ten-fold enhancement, rising from 13 to 145 & micro;V/K. Due to this synergistic effect between mobility and the Seebeck coefficient, a maximum power factor of 27.1 & micro;W/mK & sup2; was achieved at 5% EtO-BCh content. These results demonstrate that EtO-BCh acts as a highly effective organic modifier for enhancing the TE efficiency of conducting polymers through morphological ordering and energy filtering mechanisms.