Switchable Mesocrystals: Synthesis, Properties and Applications

• Applicants: Professor Dr. Peter Baum, since 4/2024; Professor Dr. Lukas Schmidt-Mende, Ph.D.
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 510996696

Mesocrystals are ordered nanocrystal superstructures in crystallographic register and can thus combine the advantageous properties of nanoparticles with those of single crystals. Although their application potential is huge and several outstanding properties were already reported, these structures are so far static in space and time. If mesocrystals could be made reversibly switchable upon an external stimulus, tailored changes of the chemical and physical properties can be expected, potentially unlocking innovative regimes of functionality. In this project, we aim to investigate and control the formation of Au-nanocrystals of various size and shape into switchable mesocrystals with dedicated structures for exploring and advancing their electronic and optical functionality. The synthetic focus will be on the stimuli-responsive assembly (light, temperature change) into 3D mesocrystals and 2D thin functional films. We will apply tailor-made ligands composed of functionalized temperature-switchable poly(2-oxazoline) di- or triblock copolymers modified with light-switchable spiropyrans for local and switchable conductivity in mesocrystal films. The structure-function relation of the assemblies for electrical, optoelectronic and optical applications will be investigated by novel optical and electronic measurement approaches, in order to guide the synthesis towards optimized functionality and performance. Our goal with these activities is to establish the synthetical and analytical basis for a new class of electrical and optical metamaterials with entirely new characteristics.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr. Helmut Cölfen, until 3/2024 (†)