Final Report Summary - STREAM (Structural evolution at the nano- and mesoscale) The project STREAM aimed to establish a novel type of kinetic experiment by combining microfluidics with micro-X-ray technology to develop a fundamental understanding of nucleation and growth of organic and inorganic nanoparticles. The idea was to map particle growth kinetics from the time- to the length scale and achieve microsecond time resolution using a combination of microbeam X-ray diffraction with controlled fluid flow and mixing in a microfluidic channel system. This method could successfully be used to demonstrate that Au- and ZnO nanoparticle nucleation and growth can be well described by classical nucleation and growth theory. It was further successfully applied to study the kinetics of micelle and vesicle formation, and of lyotropic phase transitions. The microfluidic technology let to the discovery that anisotropic particles align perpendicular to the flow-direction in narrow microchannels and upon droplet breakup during Rayleigh instability. Furthermore we could demonstrate the generation of liquid microjets with sub-micrometer diameter, and in addition could use microfluidic methods to fabricate collagen fibers with superior mechanical properties compared to natural collagen.
