Research: Synthesis

CURRENT RESEARCH
Processes for synthesis of nanomaterials with customized properties.

GOAL
Our goal is to understand the formation and growth processes of nanomaterials and, based on this knowledge, to produce specific materials with tailored properties. We use this know-how to develop suitable processes all the way through to industrial applications.

HIGHLIGHTS

  • Pilot-plant-scale systems synthesize at a rate of up to 1 kg/hour
  • Laboratory reactors with extensive in situ and online measurement technology
  • Product morphology is variable, e.g., small, separate particles or large, fractal aggregates
  • Extremely pure nanoparticles are produced using laser ablation, without costfor many materials

GAS-PHASE SYNTHESIS
Gas-phase synthesis can be used to produce extremely pure materials in continuous processes – the ideal situation for scaling up to production volumes. Our focus is on vaporizable precursors, but we also work with liquid and solid precursors that are converted to the gas phase, either immediately before, or within the reactors (flame, plasma, and hot-wall reactors). We also use direct plasma vaporization via electrical arc discharge, because this highly efficient process uses elemental materials, such as metals, instead of precursors.

Pilot-plant-scale systems enable us to synthesize nanomaterials of various compositions, sizes, and morphologies for technologically applicable quantities of up to 1 kg/h. Our process technologies allow us to produce a very wide range of materials. We primarily synthesize semiconductor materials, oxides, and multi­phasic composites.

Using extensive online and in situ diagnostics, we continuouslyrecord process and product data in order to analyze and improve our processes. We even have the ability to make targeted modifications to materials in the gas phase and, for example, define the surface properties or design aggregate structures. Selected products are then moved to the liquid phase, making them available for immediate use in processes such as printing. We collect data about synthesis under ideal conditions using highly specialized laboratory equipment. This data is combined with results from process simulations (p. 27) in order to better develop scalable processes. The resulting systems, on the pilot-plant scale, are significantly closer to the facilities that are in actual use in industry than idealized academic laboratories.

The particular combination of synthesis on an indus­trially relevant scale with the analysis and characterization systems at our disposal is unmatched anywhere in the world. As a result, we expect to achieve new fundamental insights into technological processes that will extend far beyond their immediate applications within NETZ.

Research­ers at UDE have been conducting intensive research on the synthesis of metal oxides, metals, and silicon and carbon species in the gas phase since the late 1990s. We also implement cost-effective manufacturing processes that can easily be scaled up to industrial scale. Our controlled synthesis processes allow for many material variations that can only be achieved through gas-phase processes.

LIQUID-PHASE LASER ABLATION
In liquid-phase laser ablation, a laser pulse is used to vaporize material from the surface of a target. Unlike other liquid processes, this is a ligand-free synthesis. No stabilizers are required, and thus there is no need for costly purification of the product. We are thereby able to manufacture extremely pure particles with ligand-free surfaces, which are ideally suited for applications in areas such as catalysis.

PARTICIPATING WORK GROUPS

  • Prof. Dr.-Ing. Stephan Barcikowski (nanoparticle polymer composites, laser-generated catalysts)
  • Dr. Sebastian Hardt (synthesis in the gas phase, scale-up)
  • Prof. Dr.-Ing. Einar Kruis (plasma vaporization)
  • Dr. Sven Reichenberger (laser based synthesis)
  • Prof. Dr. Christof Schulz (high-temperature kinetics)
  • Dr. Hartmut Wiggers (flame and plasma reactors, pilot systems)
  • Prof. Dr. Markus Winterer (hot-wall reactors)
  • Dr. Nicolas Wöhrl (plasma synthesis)
List of all projects