Research

Nanoparticles possess characteristic and unique physical / functional properties. Their size, shape and composition determines the ultimate properties. Chemical synthesis control enables tailoring these physical properties.­­ We synthesize and surface functionalize inorganic nanoparticles, in particularly metal oxide nanoparticles, by means of bottom-up wet chemistry and subsequently use these as building blocks to assemble functional supraparticles.­ A main interest is on magnetic, luminescent and adsorber nano building blocks.

Selected publications:

We start from synthesizing inorganic nanoparticle building blocks by means of wet chemistry. Via control over the wet chemical synthesis parameters, the size, shape and composition of the nanoparticles, thus their physical properties (e.g. optical or magnetic or adsorber or catalytic properties), can be tailored. From collaboration partners, we obtain further inorganic or organic nano or molecular building blocks.

By means of spray-drying and other methods, we assemble the different building blocks to more complex entities, so-called supraparticles. We study how the assembly process can be influenced to tailor the supraparticles`s composition and structure as this determines the ultimate functional properties of the supraparticle systems.

Selected publications:

One major focus of our current research is on creating supraparticles which carry a unique ID, i.e., which possess a fingerprint.
Installing an ID in one single particle is achieved by assembling supraparticles from nano building blocks with well-defined physical properties in specifically defined ratios. We do this either with optical or magnetic systems. Furthermore, we equip particles with monitoring or recording functionalities. Our ultimate aim is to create „communicating particles“ which can be employed to track processes, keep materials in use, trace material components and enable smart recycling approaches.

Selected publications:

Reichstein J., Miller F., Wintzheimer S., Mandel K.:
Communicating Particles: Identification Taggant and Temperature Recorder in One Single Supraparticle
In: Advanced Functional Materials (2021)
DOI: 10.1002/adfm.202104189

Müssig S., Reichstein J., Prieschl J., Wintzheimer S., Mandel K.
A Single Magnetic Particle with Nearly Unlimited Encoding Options
In: Small (2021)
DOI: 10.1002/smll.202101588

Miller F., Wintzheimer S., Reuter T., Groppe P., Prieschl J., Retter M., Mandel K.
Luminescent Supraparticles Based on CaF2-Nanoparticle Building Blocks as Code Objects with Unique IDs
In: ACS Applied Nano Materials 3 (2020), p. 734-741
DOI: 10.1021/acsanm.9b02245

Wintzheimer S., Reichstein J., Wenderoth S., Hasselmann S., Oppmann M., Seuffert MT., Mueller-Buschbaum K., Mandel K.
Expanding the Horizon of Mechanochromic Detection by Luminescent Shear Stress Sensor Supraparticles
In: Advanced Functional Materials 29 (2019), Article No.: 1901193
ISSN: 1616-301X
DOI: 10.1002/adfm.201901193

We aim at designing supraparticles which can be added to fluids and interact specifically with target substances in these fluids. The ultimate goal is either an adsorption of the target substance onto the particle`s surface, or an interaction of the target substance with the building blocks of the supraparticles. As a result, as the particles typically also possess magnetic properties, target substances can either be removed and recovered from the fluid with the help of the supraparticles, or the supraparticles act as detectors and indicate the presence and concentration of the target substance.

Selected publications:

Supraparticles are considered as key to equip surfaces with interactive functionalities. We aim at creating surfaces that can optically indicate external influences (for example create surfaces that change color upon encounter of a target gas or upon shear stress) or whose surface properties can be switched (for example create a surface which can change its color or its temperature upon a magnetic switching event, or witch can catch and release substances).

Selected publications:

We started to look into the cooperative interplay of stimulable and catalytically active building blocks united in one single supraparticle entity.

More ist yet to come…