N-Lauroylsarcosine capped silver nanoparticle based inks for flexible electronics

Silver nanoparticles stabilized by an amino and fatty acid (C12) derivative—n-lauroylsarcosine with the average size of 8.4 nm have been obtained via the reduction of the silver nitrate with hydrazine in o-xylene at room temperature. The synthesized silver nanoparticles were investigated by transmission electron microscopy, powder X-ray diffraction, UV–Vis- and IR-spectroscopy. Thermal decomposition and removal of the capping agent from the surface of the nanoparticles have been studied by thermogravimetric analysis. It was determined that n-lauroylsarcosine is removed from the surface of the nanoparticles in two stages at a temperature range of 110–210 °C. Ink consisting of the silver nanoparticles capped with n-nauroylsarcosine has been prepared in o-xylene. Its physical properties and stability have been studied. Silver layers were formed by spin coating the developed ink on a polyimide substrate. The structure and electrical properties of the conductive films obtained at different curing temperatures have been studied. It was found that, after annealing at various temperatures in the range of 100–250 °C, the deposited layers have the different structures, which determine the electrical properties. In the case of the n-lauroylsarcosine capped silver nanoparticles, low resistivity of the film (<10 µΩ × cm) is achieved at lower temperatures (130–150 °C) as compared to that reported earlier for nanoparticles stabilized by fatty acids with the similar carbon chain lengths.