Experimental study of continuous ultrasonic reactors for mixing and precipitation of nanoparticles

Nanoparticles can be synthesized by precipitation. State-of-the-art is the precipitation of nanoparticles in stirred tanks or high-pressure T-mixers. The study presents two new reactor concepts for continuous precipitation of nanoparticles. Both of them utilize ultrasonic sound as a mixing accelerator. The first reactor has a conical chamber (10 mL), which is used to study the micromixing quality, the cavitation intensity and the precipitation of barium sulfate nanoparticles. The second reactor has a so-called cavitational chamber (2.5 mL), which is an optimized conical reactor. Both reactors are compared with each other with respect to the properties of the products. Additionally, the influence of the ultrasonic output from the transducer to the liquid and the feed rate are demonstrated.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (83 K)Download as PowerPoint slideHighlights► Analysis of micromixing quality, cavitation intensity, and precipitation of barium sulfate. ► Two different reactor geometries are compared with each other. ► Aim is to find optimal operation conditions of each reactor, without decoupling the sonotrode from the liquid. ► Optimal parameters for feed rate (2.4 L/h) and ultrasonic power (20−40 W) exist.