Characterization of nanoparticles in emulsions using broadband light scattering

In a variety of industrial and scientific applications, the production of particles in the liquid phase by means of (melt) emulsification plays an important role, for example in the production of powders for additive manufacturing or for pharmaceutical applications. In the latter, for example, the release rate of the active ingredient can be influenced by the specific surface area of the particles and can thus be specifically adjusted by the particle size distribution. Autonomous control methods are to be developed and used to set a desired particle size distribution and thus improve production processes. For these purposes, however, online and real-time capable in-situ measurement techniques in the process are essential.

To this end, a novel light scattering technique based on elastic light scattering is developed in the working group Particle Measurement. Compared to existing techniques such as laser diffraction, which usually requires a sample to be taken or passed through a bypass, the new approach is based on broadband light scattering and detection in the backward scattering direction. In particular, this allows in situ determination of particle size distributions during melt emulsification without a bypass for particles in the sub-micrometer range. In addition to the fundamental development of the technique, the focus is in particular on the adaptation to higher particle concentrations.