Continuous Synthesis of Gold Nanoparticles in a Microreactor

Abstract

A continuous flow microreactor was used for the synthesis of gold nanoparticles (5 to 50 nm) directly from a gold salt (HAuCl(4)) and a reducing agent (ascorbic acid). Experimental parameters were optimized to obtain narrow size distributions, which were at average two times narrower than those obtained in a conventional synthesis. Additionally, two approaches, i.e., elevation of pH during reaction and hydrophobization of internal reactor surfaces were tested to suppress reactor fouling.

Continuous flow synthesis of ultrasmall gold nanoparticles in a microreactor using trisodium citrate and their SERS performance

“…2, i.e. that the fouling did not affect the particle size to a great extent, as was also observed by Wagner and Köhler (2005). However, for the FEP tubing, there were some larger size particles (FEP_2 in Fig.…”

The Mixed-Electrode Concept for Understanding Growth and Aggregation Behavior of Metal Nanoparticles in Colloidal Solution

“…Important insights into the role of electrostatic and electrochemical effects on the growth and behavior of nanoparticles came from microfluidic synthesis experiments. These experiments supplied particle populations of high homogeneity and high yield [16][17][18], which supported a rational interpretation of underlying mechanisms. As well as composed spherical metal nanoparticles [19], metal rods, cubes, polyeders [20] as well as flat nanotriangles had been prepared to a high quality using microfluidic techniques [21].…”

Synthesis and Characterization of Gold Nanoparticles by Tryptophane

“…Nanoparticles are being formed in various sizes, therefore, their absorption spectra vary and the obtained peak depends on the size of the nanoparticles. Wagner et al [28] Humbert et al [40] and Kumar Jena et al [41] synthesized gold nanoparticles in the ranges of 5-50, 20 and 60±5 nm showing maximum absorption at λ 527, 525 and 532 nm respectively revealing that maximum absorption of synthesized gold nanoparticles varies with sizes of the synthesized nanoparticles. …”

“…Various reagents have been reported to serve as stabilizing agent. These include the polymers such as different kind of polyethyleneglycol [24][25] , polyvinyl alcohol [26] , polyvinyl pyrilidon [27,28] and the surfactant viz, sodium dodycel sulfate [29][30][31] , tween 80, triton [32] and carbohydrates like chitosane [33] . In this study attempts are made to synthesis gold nanoparticles by chemical reduction technique employing L-Tryptophane as reducing agent.…”