I am interested in theoretical statistical physics, in particular in the field of soft matter and complex systems. My research field also includes electric double layers and their application to energy- and environmental science. One focus of my work is on structure and correlations in the described systems. In particular, I study
- active Brownian particles and conditional three-body forces,
- hard spheres and their phase transitions,
- charged colloidal and ionic particles,
- ionic fluids and electric double layers (EDLs),
- energy storage in EDLs with impact to supercapacitive technologies like supercapacitors, capacitive mixing (Capmix) for blue-energy harvesting, and capacitive deionization (CDI) to recover and desalinate water,
- the thermal voltage rise and thermocapacitive energy conversion,
- new heat-to-current conversion technology,
- interfaces and phase separations,
- driven colloidal suspensions,
- clustering, nucleation, and percolation.
The most important model system I use is the primitive model of (charged) hard spheres. The impact of this model stems from the fact that many short-ranged repulsive pair potentials from colloidal soft matter systems can be mapped onto that of hard spheres. For this reason, the initially purely theoretical model has been reconstructed in laboratories to unveil even its last secrets.
Electric double layer (EDL)
Figure 1. Sketch of the electric double layer (EDL) at a positively charged flat electrode.
Figure 2. Sketch of (from right to left) a supercapacitor, its porous electrode, and the EDL.
Active Brownian particles
Figure 3. Snapshot of a system of active Brownian disks.
© A. Härtel (2021)