Poly (3,4-ethylenedioxythiophene)/ Polypyrrole/ Carbon Nanoparticle Ternary Nanocomposite Films with Enhanced Thermoelectric Properties

ABSTRACT The different impacts of graphene (GNS) and multi-walled carbon nanotube (MWCNT) on the polypyrrole (PPy)-based composites systems have been investigated. PPy/GNS and PPy/MWCNT binary composites were firstly obtained by in situ polymerization. Then poly(3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) was employed to prepare PEDOT: PSS-PPy/GNS (PGNS) and PEDOT: PSS-PPy/MWCNT (PMWCNT) ternary nanocomposite films. PGNS films exhibit uniform layered structure and possess better crystallinity than PMWCNT composites films. Structural analyses reveal that PPy/GNS interact stronger with PEDOT chains, and PEDOT molecular has greater effect on the π-π conjugated structure of PPy/GNS than that of PPy/MWCNT. In particular, when the mass ratio of PPy/GNS to PEDOT: PSS was 70%, PGNS composites show excellent thermoelectric performance with the maximum power factor at room temperature of 82.22μW/mK2, which is among the highest value of PPy/GNS-based composites, and the optimal power factor of 55.28μW/mK2 goes to PMWCNT films when the mass ratio of PPy/MWCNT to PEDOT: PSS was 5%.