Chemists have developed a new method to precisely control the length of fatty acids chains, creating synthesised materials with tailor-made properties. In future, a special layered structure could be used for high-tech membranes.
Chemistry is sometimes a matter of finding the right size. One example of this is biosynthetics and their constituent vegetable fatty acids: each fatty acid is made up of molecular chains of a particular length. The lengths and composition of these molecular chains determine which material can be synthesised from the fatty acid. If the length of these molecular chains could be precisely controlled, scientists would have a building block to synthesise completely new materials with tailor-made properties.
Chemist Prof. Dr. Stefan Mecking and his team have developed just such a method at the University of Konstanz in Germany. Last year they demonstrated how the length of molecular chains in vegetable fats could be doubled and redoubled to achieve the length needed for a customised synthetic. Research on multiplying molecular chains is now going a step further: Mecking will be working with colleague Prof. Dr. Karen Winey from the University of Pennsylvania on characterising the properties of these new synthesised materials and advancing the existing method. This research is funded with 350,000 euros by the Baden-Württemberg Foundation, which promotes international top-level research in the region.
Catalytic doubling process
"We have found a catalytic means of synthesising polyethylene-like molecules with a very high level of precision. Two fatty acid molecules from rapeseed or algae can be attached to each other on each end without them being damaged," says Mecking, describing the synthesis of the new material, and explains, "The doubling process is catalytic and is thus especially suited for industrial application." As Winey’s structural analyses demonstrate, the new synthetic molecules exhibit an unusual layered structure. This unique structure could be suitable for ionic conductivity, opening up many new applications.
The chemists are working, in particular, on a layered structure in which each new layer of synthesised material alternates with an ionic layer. This layered material is particularly stable and could be useful as a high-tech membrane for future generations of batteries and for water treatment. "Our research project will help us to better understand and improve upon the properties of this new synthesised material and the layered structure it adapts," says Mecking.