Synthesis and Characterization of Gold Nanostars as Filler of Tunneling Conductive Polymer Composites

Highly multibranched gold nanostars were obtained by a room-temperature synthesis assisted by deep-eutectic solvents (DES). The concentration of the ascorbate ions and the presence of water in the solution were found to both have a profound influence on branch formation. A growth mechanism of the nanostar is therefore proposed from the analysis of the particle dimensions, the aspect ratio of their protuberances, and the gold crystal size. These spiky nanoparticles would find an application as conductive filler in polymeric piezoresistive composites, based on a tunneling conduction mechanism.