Regularities of the formation of silver nanoparticles with oligostyrylmonocarboxylate ligands in ED-20 oligomer

Abstract

Regularities of the formation of silver nanoparticles according to the reduction reaction of silver oligostyrylmonocarboxylate with ED-20 resin in the absence of hardening agent were studied at 60–75°C by UV/Vis spectroscopy and IR spectroscopy, transmission electron microscopy, and viscosimetry. Spherical silver nanoparticles with oligostyrylcarboxylate ligands characterized by diameter equal to 1.8 ± 0.2 nm and tendency toward ordered disposition in space were obtained. The process of formation of nanoparticles includes consecutive formation of diphilic complexes of silver carboxylate with epoxy resin, Ag+ → Ag0 reduction, and formation of (Ag0) n nuclei at the ends of the diexpoxy component and/or along the oligomer chain. The activation energy values of formation of nanoparticles during the “inductive period” and at the stage of accumulation as well as the activation energy of viscous flow of ED-20 were measured. The threshold temperature of formation of narrow-size silver nanoparticles in epoxy oligomer ED-20 equals 75°C.