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

Abstract

Silver nanopowders were prepared from silver 2-ethylhexylcarbamate (Ag-EHCB) complexes by simple thermal reduction at 85 o 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, AgNPs 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 o C in air and were found to have resistivity values of 2.9 × 10 −8 Ω·m.

Recent Advances in the Chemistry of Metal Carbamates

“…The resulting silver-coated materials have been investigated for their conductive properties [345][346][347][348] and/or antibacterial/antimicrobial activity [349][350][351][352][353][354][355]. In addition, if the reduction is performed in the presence of ethyl cellulose, a silver paste is obtained, and this can be deposited on a suitable substrate and sintered to provide a silver conductive film [356][357][358].…”

“…The synthesis of silver nanoparticles (and related nanocomposites) by thermolysis of silver carbamates is preferable respect to more traditional protocols (i.e., reduction of AgNO 3 with NaBH 4 or sodium citrate), in that it does not require any reducing agent and thus avoids the presence of undesired inorganic species in solution. Moreover, the colloidal AgNP dispersion is stabilized by the ammonium carbamate co-product acting as surfactant (vide infra), and the spherical particles exhibit a rather narrow size distribution [352,357].…”

Silver loading on poly(ethylene terephthalate) fabrics using silver carbamate via thermal reduction

“…20 Recently, a silver carbamate solution was used to prepare AgNPs through a controlled thermal reduction, which is one of the simplest methods that can be used to prepare AgNPs. 21,22 This method has a great advantage in that it produces essentially 'clean' AgNPs, that is, AgNPs that are free of inorganic ions. Moreover, no additives (e.g., solvent, surface active agent, or reductant) need to be used.…”

Facile preparation of antibacterial, highly elastic silvered polyurethane nanofiber fabrics using silver carbamate and their dermal wound healing properties

“…The silver peaks on the nanofiber surfaces evident by EDX analysis confirms that AgNPs can be generated from the thermal reduction of silver carbamate precursor via an electrospinning process. 31,32,33 <Fig. 5>…”