Preparation of Highly Stabilized Silver Nanopowders by the Thermal Reduction and Their Properties

Silver nanopowders were prepared from silver 2-ethylhexylcarbamate (Ag-EHCB) complexes by simple thermal reduction at 85∘C without any reducing agent in organic solvent. 2-Ethylhexylammonium 2-ethylhexylcarbamate (EHAEHC) was investigated in terms of their abilities to stabilize the silver nanoparticles (Ag-NPs) and its subsequent effects on the preventing aggregation between Ag-NPs. Conditions (concentration of stabilizer and reaction time) used to reduce Ag-EHCB complex were systematically varied to determine their effects on the sizes of Ag-NPs. The formation of the stabilized Ag-NPs were easily monitored by UV-vis spectroscopy and characterized by TGA, TEM, SEM and XRD. When EHAEHC was used as a stabilizer, Ag-NPs of 10-30 nm in diameter were easily obtained in high yield. Silver patterns were obtained from a silver nano-paste by heat treatment at 200∘C in air and were found to have resistivity values of 2.9×10⁻⁸\;Ω·m .