The Plenty of Room in the World of Hierarchically Composed Particles -Micro-Scale Challenges between Chemistry and Engineering

J. M. Köhler, X. Li, N. Visaveliya, Raminta Mazetyte, Jonas J. Kluitmann and K.-P. Kronfeld, Techn. Univ. Ilmenau, Dept. of Physical Chemistry and Microreaction Technology

Living nature shows that complex functional systems as biological cells are based on hierarchical organization of nanostructures in space. In analogy, composed micro and nanoparticles can be regarded as a technical approach for realizing hierarchical-constructed micro objects. Scale-adapted microfluidic techniques have been applied for generation of micro and nanoparticles with narrow size distribution at different size levels. Using these techniques, hierarchically composed particles with three, four and five levels of integration were realized. Thus, integration and spatial distribution of metal nanoparticles of few nanometers in size in sub-mm gel particles can be controlled. Such particles could be of interest for catalysis and sensor applications. As an example, silver nanoparticle-containing polymer particles are shown as primary transducers for SERS sensing. Finally, some general challenges for further development of nanotechnology are discussed.