Controllable Synthesis of Silver Nanoparticles Using a Double-Layer Y-Shaped SAR Micromixer

Abstract

Based on the advantages of microfluidics in the field of nanoparticle synthesis, a controllable synthesis method for silver nanoparticles using a double-layer Y-shaped splitting and recombination (SAR) micromixer is proposed. First, the liquid phase synthesis mechanism of silver nanoparticles, the working principle of the double-layer Y-shaped SAR micromixer, and the mixing performance of micromixer at different Reynolds number (Re) are analyzed. Then, the micromixer is used to synthesize silver nanoparticles, and the effects of reductant concentration, polyvinylpyrrolidone (PVP) and inlet flow rate on the size, distribution and morphology of the synthesized silver nanoparticles are investigated comprehensively. The synthesized silver nanoparticles are characterized by UV-spectrometer and transmission electron microscopy (TEM). The experimental results show that the reductant concentration, PVP, and inlet flow rate have a direct impact on the size, distribution, monodispersity and morphology of the synthesized nanoparticles. The moderate reductant concentration makes the size of silver nanoparticles larger and the size uniformity is better. Adding PVP to the experimental reagent can prevent the aggregation of silver nanoparticles, consequently, the synthesized particles have a uniform distribution and a better morphology. The changes in inlet flow rate and Re directly affect the mixing efficiency, which in turn affect the formation of silver atoms and silver nanocrystal nuclei and have a greater impact on particle concentration. The proposed micromixer has excellent mixing performance and can be used in other fields such as controllable synthesis, biomedicine and microchemical systems.