Direct Synthesis of Anisotropic Metal Particles by Ink Jet Printing Technique

Abstract

Here we report the synthesis of nanoparticles with aspect ratios of up to five by synthesis in small concentrated volumes of reactants using an ink-jet printer. Silver and gold nanoparticles were synthesized rapidly on transparent sheets using a commercial ink jet printer. A commercial inkjet printer was modified by replacing conventional inks with different reactants including silver nitrate, ammonium-complex silver, gold chloride reduced by ascorbic acid. The reaction was allowed to occur directly on the substrate within a short reaction time and confined reaction volume defined by the droplet size on the substrate. The nanoparticles and microrods formed on the substrate depend on pH and ionic concentrations of the solutions. The pH of the solutions is an important factor controlling the aspect ratio of microrods. When the concentration of silver ions in the reactant solution was increased the number of particles deposited on the substrate increased subsequently. Anisotropic particles could be formed uniformly over very large area surfaces (1mm x 20mm). This method can be suitable for rapid synthesis of anisotropic particles for potential application in metal-enhanced fluorescence sensing, antibacterial coating, anti reflection coatings, amongst others.