Microfluidic synthesis of multiscale polymer composite particles

• Applicant: Professor Dr. Johann Michael Köhler
• Subject Area: Preparatory and Physical Chemistry of Polymers ; Chemical and Thermal Process Engineering ; Synthesis and Properties of Functional Materials
• Term: from 2014 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258420769

In the next project phase, it is planned to use the developed steps of the microfluidically assisted generation of composite particles with two and three organization levels for the synthesis of multiscale microparticles with up to five levels of spatial organization. Continuous micro flow processes will be used for the integration of organic and inorganic nanoparticles and composed nanoparticles with well-defined sizes, composition and geometries into polymer micro particles. Droplet microfluidics and light-induced polymerization and cross-linking of the polymer matrix will be applied for generation of the complex composed microparticles. Cross-flow, Co-flow and flow focusing are applied for the generation of droplets of monomer/nanoparticle mixtures with narrow size distribution.The principle of controlled electrostatic repulsion will be used for ensuring a high stability of the colloidal state at the nanoparticle level. The control of electrical surface charges will be achieved by surface functionalization which has been already successful used in the first project phase. In addition, the control of surface charge will also be used for temporal reduction of repulsion effects and for limited nanoparticle aggregation. It is planned to investigate this strategy for step-wise formation of larger nanoparticles by assembling smaller ones in order to obtain nested internal substructures at the higher nanometer and lower micrometer level. Assemblies of particles in the size range between about 2 and 20 nm will be incorporated into particles in the submicron range (150 to 500 nm) which can be further integrated in domains of composed microparticles. The goal of the project is to show that hierarchically constructed particles of different components can be generated by a general strategy involving microfluidic steps. The new syntheses should also demonstrate that micro reaction technology is well suited for generation of new types of composite particles. Thus, the project will contribute to the general bottom-up strategy of nanotechnology by bridging the world of nanomaterials and microparticles. At the same time, it is expected that the project will show a general approach for addressing the large combinatorial variety of composed particles in the nanometer and micrometer range.

• DFG Programme: Research Grants