NanoShape - Particle-filled thermoplastics with defined nanostructured particle geometry

The Department of Plastics Engineering is launching a new research project, funded by the German Research Foundation (DFG), to develop and characterize nanostructured particles for plastic composites. The goal is to optimize the properties of thermoplastics through targeted modifications of the particles’ mechanics and geometry.

The project is a collaboration between the Institute for Nanostructure Technology and Analytics, Department of Technical Electronics (Hillmer Research Group), and the Institute for Materials Science, Department of Plastics Engineering (Heim Research Group). Over the course of three years, the Hillmer Research Group will focus on developing innovative methods for producing mechanically highly stable particles. Initially, the focus will be on producing particles on a larger scale (>5 mm in length) to determine macroscopic material properties such as the modulus of elasticity and to select suitable materials. In the subsequent phase, particles with complex geometries will be developed and processed. The Heim Research Group is responsible for the mechanical characterization of the developed particles as well as their integration into a thermoplastic matrix (polypropylene and polylactide). In this process, critical factors such as temperature and shear stress are analyzed, as these influence the shape and size of the particles in the composite. The final evaluation of the composite materials is carried out through detailed investigations of the mechanical properties and the particle distribution following processing in a twin-screw extruder and in the injection molding process.

Previous research shows that the mechanical properties of particle-reinforced plastic composites depend not only on the fillers used, but also on their shape, size, and surface structure. While conventional fillers often have simple geometries (e.g., glass beads or glass fibers), the NanoShape project offers the possibility of using optical lithography, nanoimprint lithography (NIL), and two-photon polymerization (2PP) to produce highly complex and precisely defined 2D, 2.5D, and 3D particles.

The central hypothesis of this research project is that the geometry of the fillers can be specifically utilized to optimize the mechanical properties of the plastic composite. The study examines the influence of particle shape, microstructure, and dimensional order. Over the course of the project, the particles will also be further miniaturized to analyze in detail the structure-property relationships between shape, size, and mechanical properties. For particles 500 μm or larger, in-situ experiments are also planned to directly visualize damage and fracture behavior. Another goal is to develop an evaluation method for quantifying the degree of damage to the particles as a function of their geometry. With this interdisciplinary approach, the NanoShape project makes an important contribution to the further development of high-performance plastic composites and to the improvement of mechanical properties through specifically structured particles.