Conducting silver networks based on electrospun poly(methyl methacrylate) and silver trifluoroacetate

Silver networks with high transmittance and low resistance were prepared on transparent substrates via a polymer-assisted electrospinning technique and post treatments. Nonaqueous media containing poly(methyl methacrylate) (PMMA) and silver trifluoroacetate (STA) were formulated and electrospun as polymer/metal-precursor nanofibers with as-spun fiber diameters ranging from 640 to 3000 nm. Nanofibers randomly deposited on transparent substrates formed a plane scaffold, which served as the raw material for the conducting silver network. Post-thermal treatment at a moderate temperature of 100 °C reduced the STA precursors to silver nanoparticles (Ag NPs). Further heat treatment at elevated temperatures thermally decomposed the organic polymer and triggered sintering of the Ag NPs into a connected one-dimensional (1D) domain. Silver fibers with diameters ranging between 800 and 4500 nm formed continuous conducting networks on the substrate surface. The sheet resistances of these conducting silver networks revealed strong correlations with the original STA/PMMA ratios and with the silver network morphologies after the polymers were removed. The material fabrication was carefully investigated, and the surface plasmon resonances (SPRs), fiber morphologies, and electrical and optical properties of the products were examined. The optimized conducting silver networks exhibited sheet resistances as low as 15 Ω/sq and diffusive optical transparencies of approximately 54%.