The team led by Prof. Dr Alex J. Plajer at the University of Bayreuth, working closely with researchers at Freie Universität Berlin, has produced a novel molecule with a flat geometry that fundamentally reverses the conventional approach to water in chemistry. “We designed the building blocks of our materials so that they possess specific binding sites that function like built‑in docking slots for water molecules,” explains Prof. Plajer. A particular feature is that these water molecules connect the building blocks at these “slots”, physically holding the material together and defining its shape and function.
“This is particularly remarkable because water often destabilises artificial structures of this kind. Our new material, however, would not exist in this form without the water molecules. Rather than having to keep water away from the structure‑forming components, we have deliberately integrated it as a structural element,” says Merlin R. Stühler, first author of the study and doctoral researcher in Alex Plajer’s group. When the building blocks are placed in pure water, they self‑assemble into long, tubular nanofibres. This leads to the formation of hydrogels that become softer or firmer depending on the temperature and can be selectively broken down.
The detailed structure of the nanofibres was elucidated at the Electron Microscopy Research Centre (FZEM) at Freie Universität Berlin. “We used single‑particle analysis, a method previously employed mainly in biology to study proteins and viruses, to decipher the structure of the fibres with exceptional precision,” explains Prof. Plajer. “This approach enabled us to visualise the exact arrangement of the molecules and understand how they interact to create the unique properties of the material.”
The water molecules embedded within the structure also enable the transmission of information: when the nanofibres encounter other molecules with a specific spatial orientation, such as naturally occurring amino acids, the material can recognise this orientation and adopt it. The nanofibres twist accordingly to match their surroundings. “In the long term, this material could be used as a biological sensor or in medical applications due to these properties. Our study thus shows that in the development of water‑based materials, water does more than merely disrupt — it actively builds, stabilises and imparts function to structures,” concludes Plajer.
