Flexible and conductive: Engineered polymer nano-filled membranes of PTh/SIS/rGO show superior electro-mechanical performance compared to the PTh/SIS polymer films.

Abstract

Electrically conductive polymers such as polythiophene (PTh) offer a combination of optical and electrical properties needed in the electronic industry. We report a processible method of fabricating conductive PTh membranes with the elastomer (styrene–isoprene–styrene, SIS) to increase the ductility of the membranes. Any conductivity compromised in the process of casting polymer blends is offset by the addition of reduced graphene oxide (rGO) fillers in the PTh/SIS blends. The resulting nanocomposite conductive membranes of PTh/SIS/rGO are assessed at different filler concentrations to determine their mechanical and electrical properties in comparison to the polymer–polymer films. Results reveal that the PTh/SIS/rGO films offer maximum tensile strength (4.01 MPa) and 1301% elongation at break compared to the polymer–polymer films. Additionally, the nano-filled polymer membranes show high electrical conductivity at 1.45 × 10⁻⁸ S/cm compared to the conductivity (1.01 × 10⁻¹⁰ S/cm) of the corresponding polymer–polymer films. This increase in electrical conductivity in the PTh/SIS/rGO membranes is due to the formation of conductive channels in the nanocomposite, which show a high percolation threshold of 4% filler. The resulting membranes are conductive, strong, and ductile and can be considered for applications in stretchable electronics.