S. Beinert

Microsystems for Dispersing Nanoparticles

Typically in the production of nanoparticles via bottom-up syntheses, agglomerates or even strong aggregates are formed which have to be redispersed in a subsequent dispersion process. Especially for the processing and screening of aggregated highly potential and cost-intensive biotechnological or pharmaceutical products, microsystems are advantageous due to high stress intensities, narrow residence time distributions, and high reproducibility as well as low volume flow. Depending on the geometry and the operating conditions of dispersing units within microsystems, various stress mechanisms have an effect on the dispersion process. However, in contrast to emulsification processes, the effect of cavitation is disadvantageous for high-pressure dispersion processes and can be avoided by applying backpressure. For the characterization and optimization of the stress intensity distribution and stressing probability in microchannels at various operating conditions, microparticle image velocimetry (μPIV) as well as single- and two-phase CFD simulations are well suited.