Tailoring Morphology and Size of Silver Nanoparticles Prepared by Polyol Method by Changing the Structure of Silver Carboxylate Precursor

Abstract

Silver nanoparticles are synthesized by reducing silver alkyl carboxylates at their high concentrations with ethylene and propylene glycol without a common use of polymeric dispersants and stabilizers. The effects of alkyl chain structure on the morphology and size of silver particles have been studied by scanning electron microscopy, transmission electron microscopy, powder X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analyses. The carboxylates that have been investigated are silver caprylate, laurate, 2‐butyloctanoate, and 2‐ethylhexanoate. It was found that the reduction temperature of straight‐chain alkyl carboxylates is in the 110–120 °C range. The particles prepared under these conditions are perfectly spherical in shape and their average size varies from 20 to 40 nm. In the case of the branched structure, the reduction process starts at around 80 °C and produces irregularly shaped silver particles with a size of 150 to 450 nm. Possible ways of controlling the parameters of the synthesized nanoparticles are proposed. This study proposes a simple and easily scalable method to prepare silver nanoparticles stabilized by a non‐polymeric stabilizer. The as‐synthesized silver particles may have applications as metallic fillers in ink and paste formulations for 2D and 3D printing to fabricate functional components and devices.