An efficient polymer for producing electrospun transparent conducting films through simple procedures and a mild post-process

Abstract

As a particular method for the preparation of metal-nanowire-based transparent conducting films (TCFs), electrospinning has some advantages that common methods don't possess, such as a low requirement for the match of substrate, no coffee rings and the ability of preparing films on curved or rugged substrates. However, at present, complex preparation procedures or high temperature treatment are usually needed to prevent electrospinning polymers from affecting the performance of TCFs. To solve this problem, polymers that are suitable for direct electrospinning with metal nanowires and can be easily eliminated under mild conditions are desirable. However, this type of polymer has been rarely reported. In this study, silver nanowires (AgNWs) were selected as the representative of metal nanowires and different polymers were tried to discover the most suitable material. The results of the experiments indicated that polyethylene oxide (PEO) (M_w = 50 000) was the most suitable polymer. The chain length of this polymer was enough to effectively wrap the AgNWs to obtain good electrospinning films and it could be easily eliminated under mild conditions because of its low melting point and excellent solubility. Then, we determined the most suitable electrospinning solution, which consists of AgNWs (0.3%), PEO (2.5%), AMP (0.2%) and DI water (97%). From this solution, uniform electrospinning films were prepared. Subsequently, this film was heated at 70 °C for 15 s to fasten the AgNWs onto the substrate and then soaked in ethanol (70 °C) for 10 s to eliminate PEO, in sequence. Finally, a good TCF was obtained. The sheet resistance and transmittance of this film were 94 Ω sq⁻¹ and 83.4%, respectively.