title: Two step continuous method to synthesize colloidal spheroid gold nanorods.
abstract: This research investigated a two-step continuous process to synthesize colloidal suspension of spheroid gold nanorods. In the first step; gold precursor was reduced to seed-like particles in the presence of polyvinylpyrrolidone and ascorbic acid. In continuous second step; silver nitrate and alkaline sodium hydroxide produced various shape and size Au nanoparticles. The shape was manipulated through weight ratio of ascorbic acid to silver nitrate by varying silver nitrate concentration. The specific weight ratio of 1.35-1.75 grew spheroid gold nanorods of aspect ratio ∼1.85 to ∼2.2. Lower weight ratio of 0.5-1.1 formed spherical nanoparticle. The alkaline medium increased the yield of gold nanorods and reduced reaction time at room temperature. The synthesized gold nanorods retained their shape and size in ethanol. The surface plasmon resonance was red shifted by ∼5 nm due to higher refractive index of ethanol than water.
authors: School of Engineering, Trinity College Dublin, The University of Dublin, Ireland. Electronic address: schandra@tcd.ie.
authors: S
authors: S
authors: Chandra
authors: School of Physics, Dublin Institute of Technology, Kevin Street, Dublin 08, Ireland.
authors: J
authors: J
authors: Doran
authors: School of Engineering, Trinity College Dublin, The University of Dublin, Ireland.
authors: S J
authors: SJ
authors: McCormack
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D010084:Oxidation-Reduction; D011205:Povidone / Q000031:analogs & derivatives; D012835:Silver Nitrate / Q000737:chemistry
chemical_list: C077842:polyvinylpolypyrrolidone; D000431:Ethanol; D006046:Gold; D012835:Silver Nitrate; D011205:Povidone; D001205:Ascorbic Acid
keywords: Spheroid gold nanorods; Surface plasmon resonance; Two-step method