A biphasic batch and continuous flow synthesis of hydrophobic gold and silver nanoparticles

Abstract

Plasmonic nanoparticles functionalized with hydrophobic ligands are required for several applications in flexible electronic, sensors and memory devices for their dispersability in polymeric matrices. In the current paper, we report a method for the batch and continuous synthesis of gold and silver nanoparticles (NPs) functionalized with oleylamine and oleic acid following a modified Brust–Schiffrin method. The role of key components of the reaction mixture in the phase transfer step is unravelled via¹H and ¹³C nuclear magnetic resonance (¹H and ¹³C NMR) spectroscopy. Gold and silver nanoparticles are characterized by Transmission and Scanning Electron Microscopy (TEM, SEM), Scanning TEM in High Angle Annular Dark Field mode (STEM-HAADF) coupled with X-ray Spectroscopy (STEM–EDX) analysis and UV-vis spectroscopy. Based on the findings for the synthesis in batch mode, we demonstrate the feasibility of the continuous flow synthesis for both gold and silver systems.