Material Sciences

Technology offer: Chemical raw materials from wood

Given the constant increase in the world’s population and the decline in fossil raw material reserves, the recovery of renewable raw materials is one of the key issues for the future. However, the aim is not only to fulfill long-term energy demand through the use of alternative, renewable, climate-friendly energy sources. Substances known as aromatics, which have been produced from oil up to now, are needed for the manufacture of thousands of everyday materials and are found, in drugs, coloring agents, plastics, and epoxy resins, among other things. And although it is possible to obtain these crucial synthesis components from wood, the conversion of wood into aromatic compounds was thus far only possible under technically sophisticated and uneconomic conditions. Researchers from the Max Planck Institut (MPI) für Kohlenforschung have now developed a method, with the help of which aromatics from wood can be made available for use as raw materials in a simple and cost-effective way.
Image: Laboratory process for the isolation of lignin from wood
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Technology offer: High-efficient thermoelectric materials

Certain materials are known to generate an electric potential when exposed to a temperature gradient (Seebeck effect) and a temperature difference when a voltage is applied (Peltier effect).
A lot of sources of waste heat are suitable for generating electrical power using such thermoelectric materials. On the other hand, there is a need to provide electrically operated cooling devices without moving parts. Therefore, there is great interest in devising thermoelectric materials with significantly higher efficiency than is currently available.

High-efficient thermoelectric materials
Picture: SEM micrograph taken from the fracture surface of a nanocrystalline SrTiO3 sample. The average grain size is equal to about 80 nm.

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MPI of Colloids and Interfaces: New microcontainers delivering medical substances to diseased tissue

Scientists from the Max Planck Institute of Colloids and Interfaces in Golm, Potsdam, have developed an effective drug delivery technique. The researchers use porous calcium carbonate microspheres as templates for the production of hollow three-dimensional balls. These microcontainers can be loaded with medically effective substances. Furtmerore, small signalling molecules can be attached to their surface, with the help of which the spheres can then find their way to diseased tissue.

Picture: Illustration of the production of colloid spheres.
© Dr. X.Yan

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Fritz Haber Institute: Improving catalysts

Insights into the process which converts carbon dioxide into methanol could make it possible to recycle greenhouse gas: There is now one less mystery in chemical production plants. For many decades industry has been producing methanol on a large scale from a mixture of carbon dioxide and carbon monoxide, as well as hydrogen. An international team, including chemists from the Fritz Haber Institute of the Max Planck Society in Berlin, has now clarified why the catalyst used in this process – copper and zinc oxide particles and a small portion of aluminium oxide – works so well. They also discovered why this reaction accelerator has to be produced in the tried and tested way. The researchers established that defects in an as yet unknown combination with mixing of copper and zinc oxide at the catalyst’s surface are the reason why the catalysts are so active. These findings could make a contribution to further improving the catalyst, and also help researchers develop catalysts that convert pure carbon dioxide efficiently. These could be used to recycle the greenhouse gas that is produced when fossil fuels burn.

Picture: The first step towards the catalyst is the most important one: Julia Neuendorf and Malte Behrens control how a mixture of copper, zinc and aluminium salts precipitate the precursor for the catalyst of the methanol synthesis in the semi-automatic precipitation reactor. © Norbert Michalke for the MPG
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Technology offer: The “raspberry-lotus” effect – stable, water-repellent and self-cleaning surfaces

Solar modules with no dust layer, clean windscreens, spectacles that never need to be cleaned – water-repellent surfaces that use the lotus effect and are self-cleaning can be used in a wide variety of applications. An invention by the Max Planck Institute for Polymer Research now enables the production of transparent and stable surfaces on which water forms droplets that drip off and remove dirt particles in the process – with the help of so-called “raspberry particles”.

Picture: The water-repellent surface of the lotus plant provides the model for the new technology (Source: MPI for Polymer Research).





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Patent: Amorphous SiBNC Ceramics – A Material That Keeps Its Cool When Hot

A great deal of energy could be saved if turbines and combustion engines operated at higher  temperatures than they currently do. Ceramic high-temperature materials make this possible. Martin Jansen, Director at the Max Planck Institute for Solid State Research in Stuttgart, has been conducting research into just such a new material for 20 years. It is now ready for the market: Amorphous SiBNC Ceramics for High-Temperature, High-Durability and Light-Weight Applications


Picture: Stable, even when it gets hot – The ceramic fibers made from silicon, boron, nitrogen and carbon can withstand extremely high temperatures.

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MPI for Intelligent Systems: Development of low friction surfaces

Friction – without it a car’s tyres or the soles of your shoes did not grip the ground, neither wheels nor feet would be able to move forward. On the other hand friction causes the economy enormous losses – the cost of machine parts rubbing against each other as a result of wear, for instance, is estimated to amount to around eight per cent of the German GDP – some 200 billion euros. Researchers from the Max Planck Institute for Intelligent Systems in Stuttgart and the University of Stuttgart arranged an experiment in which microscopically small surfaces rub against each other. This way they observed for the first time how friction takes place on an atomic level and found out why objects with the same structure create more friction when they rub against each other than those with differing structures. The results will could be the basis for the construction of micro- and nano-machines that are as low in friction as possible.


Picture: Friction by region – When two microscopic surfaces with the same structure slide over one another, not all particles move at the same time. In fact, the particles in some areas slide (blue spheres), thus distorting their configuration. The other particles (green) stay where they are in the hollows of the surface. © Thomas Bohlein/Ingrid Schofron

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Finally: No more dirty windscreens thanks to self-cleaning glass

Due to its spherical nanostructure, fluorinated silica coating repels water and oil very effectively: Eyeglasses need never again to be cleaned, and dirty windscreens are a thing of the past! Researchers at the Max Planck Institute for Polymer Research in Mainz and the Technical University Darmstadt are now much closer to achieving this goal. They have used candle soot to produce a transparent superamphiphobic coating made of glass. Oil and water both roll off this coating, leaving absolutely nothing behind. Something that even held true when the researchers damaged the layer with sandblasting. The material owes this property to its nanostructure. Surfaces sealed in this way could find use anywhere where contamination or even a film of water is either harmful or just simply a nuisance.
Picture: A surface from which oil and water simply bounce off: The superamphiphobic coating is not even wet by the low-viscosity oil hexadecane, which would spread out even on a non-stick coating. Therefore, a drop of the liquid first bounces up off the surface before coming to rest on it as an almost perfect sphere. The superamphiphobic properties arise from the sponge-like glass structure that researchers at the Max Planck Institute for Polymer Research have developed. © Science / Xu Deng – MPI for Polymer Research

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