Polyaniline − carbon nanohorn composites as thermoelectric materials

Abstract

Thermoelectric materials can convert heat into electricity when a temperature gradient is present. The investigation of conductive polymers such as polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) as active materials for thermoelectric generators in the room temperature range is gaining interest because of several key advantages offered by these materials. The relative ease of solution processing, their mechanical stability and flexibility together with low density and low thermal conductivity make conductive polymers suitable for integration in a thermoelectric generator. Polymers offer remarkably low thermal conductivity values but modest Seebeck coefficient and electrical conductivity. In this work, polymer/inorganic nanocomposites of PANI with carbon particles such as single wall carbon nanohorns (SWCNHs) were prepared via solution mixing of the precursors in order to increase the electrical conductivity by means of polymer matrix/nanohorn electronic junctions. The electrical conductivity and Seebeck coefficient were estimated on PANI/SWCNH films and pressed pellets and through-plane thermal conductivity was determined on films. The thermal stability of PANI/SWCNH composites was evaluated by means of TGA/DSC coupled with residual gas analysis. It was found that a proper concentration of SWCNHs in PANI−(+/−)-camphor-10-sulfonic acid (CSA) film was effective in increasing the electrical conductivity without decreasing the Seebeck coefficient.

Percolative Composites with Carbon Nanohorns: Low-Frequency and Ultra-High Frequency Response

“…According to the data reported, the conductivity of CNHs could vary from 10 −3 S/m [15] to several hundred S/m [16,17], which is probably caused by the different densities of the materials. Addition of CNHs to dielectric or conductive polymer increases the conductivity slightly [18,19,20,21,22,23]. The permittivity and microwave shielding effectiveness (SE) of the materials with CNHs have barely been investigated.…”

“…The permittivity and microwave shielding effectiveness (SE) of the materials with CNHs have barely been investigated. We have found just a few works devoted to three-component polymer composites, where the second filler was presented by graphene [18,19], ferromagnetic particles [20] or their hybrids [21,22] in addition to the CNHs.…”

Facile Green Vacuum-Assisted Method for Polyaniline/SWCNT Hybrid Films with Enhanced Thermoelectric Performance by Interfacial Morphology Control

“…It is highly desired that filling a one-dimensional conductive template, such as carbon nanotubes (CNTs), ,,,,,− into conducting polymer-based composites is an effective method to enhance the electrical conductivity and the Seebeck coefficient while maintaining a low thermal conductivity for the composite system, − thus enhancing the power factor. Among the different conducting polymers, polyaniline (PANI) is considered as a promising material in TE applications due to its ease of synthesis, chemical redox reversibility, nontoxic property, environmental stability, chemical stability, and unique doping/de-doping process. − CNTs have a certain orientation effect on the PANI molecular chains under the action of a solvent, which is not only beneficial to the recombination of the two materials but also help in the improvement of the thermoelectric properties of the composites by the interfacial effect. − To achieve this objective, many attempts have been made in the PANI based-CNT composites.…”

Itaconic acid–doped polyaniline/MWCNTs nanocomposites for microwave absorbing materials

“…Polyaniline (PANI) has been studied mostly among the conducting polymers because of its advantages such as high electrical conductivity, good microwave-absorbing properties, easy synthesis, and commercial viability. [4][5][6][7][8] As one of the four well-known organized carbon states on Earth, multiwalled carbon nanotubes (MWCNTs) were discovered by Iijima in 1991. 9 Nowadays, increasing research was carried on MWCNTs for their high specific surface area and excellent electrical and mechanical properties.…”

“…Polyaniline (PANI) has been studied mostly among the conducting polymers because of its advantages such as high electrical conductivity, good microwave-absorbing properties, easy synthesis, and commercial viability. 4 –8…”