Largely enhanced electrical conductivity of layer-structured silver nanowire/polyimide composite films by polyaniline

Electrical conductivity (σ) and mechanical properties are two major concerns for layer-structured films used in electronic devices. It is unavoidable to significantly reduce the mechanical integrity of layer-structured films for adjoined conducting-layer and polymer layer and also greatly increase the cost for expensive conductive fillers in order to enhance σ by simply increasing conducting filler content. This paper reports for the first time the preparation of silver nanowire (Ag-NW)/polyimide (PI) layer-structured composite films with greatly enhanced σ and maintained good mechanical properties by polyaniline (PANI) utilized in the PI substrate layer to regulate its potential barrier for the purpose of reducing the tunnelling resistance between Ag-NWs. Consequently, σ is greatly enhanced by up to 8.7 times (over 1000 S/cm) while the high tensile strength of the layer-structured conducting composite film is maintained by 95% (over 75 MPa) via introduction of PANI at low contents up to 20% of PI. This work provides a simple strategy for development of high-quality thin films for electronic devices simultaneously possessing high σ and good mechanical properties.