7 10 2019

Graphite Material with Unique Structural Properties

Scientists from the Faculty of Chemical Technology at Poznan University of Technology in cooperation with an international research team have developed a graphite material with unique structural properties, using the protein skeletons of marine sponges as a raw material. This discovery opens up new opportunities for modern materials science, especially in the new field of Extreme Biomimetics.

Extreme Biomimetics is a scientific field which has been initiated in 2010 by prof. Hermann Ehrlich from TU Bergakademie Freiberg and is currently intensively developed in cooperation with the team of prof. Teofil Jesionowski at the Poznan University of Technology. It applies to the study of natural phenomena and biomaterials which occur "outside the human comfort zone" and the transfer of this knowledge to laboratory practice for the synthesis of next-generation bioinspired materials with properties that predispose them for application under conditions of extreme load at an industrial scale. Extreme biomimetics is very popular all around the world due to the development of new, three-dimensional composites with a hierarchical structure. To this end, scientists propose the use of renewable, naturally occurring and non-toxic protein skeletons with dimensions ranging from centimeters to meters. The designed structure reflects the shape and size of spongin, a collagen-containing protein structure used for the formation of skeletons of sea sponges. The spongin structure consists of nanofibers which form multilayer fibers with a diameter of 100 microns. These fibers combine to form a complex, porous, hierarchical 3D network with exceptional structural, mechanical and thermal properties. Spongin is a protein with high thermal stability up to 360°C under an oxidizing atmosphere. Without oxygen, spongin can be carbonized at 1200°C without the disruption of structure at the nanometer level. Interestingly,  in order to heat the sponge, the scientists used the same equipment that is used to melt steel. Under conditions which are so unusual for biopolymers, spongin evolved into a type of nanoporous graphite, however, interestingly, the carbon material obtained this way reflected the structure of a triple helix, which is characteristic for the original collagen. Surprisingly, the graphite obtained from spongin charring was characterized by such high mechanical stability that it could be cut to any shape using a metal saw.

Now that we have analyzed the nanostructure of graphite fibers obtained from carbonization of spongin, we can suggest the preparation of bioinspired centimeter-sized catalysts for advanced practical applications, which will be produced by coating surfaces with selected functional metals” - remarked Prof. Teofil Jesionowski.

For two years, a team consisting of 28 people studied the prefabricated three-dimensional biopolymer sponge skeletons (organisms which appeared on Earth 600 million years ago) in order to develop biomimetic model systems that would serve as an alternative to analogous plastic structures in advanced material chemistry.

We have found a new way to utilize sponges, which have been known since ancient times, and which were previously used for hygienic and cosmetic purposes. From now on, they can also be used in modern technologies” – commented Prof. Hermann Ehrlich

The results of the study have been recently published in a prestigious journal Science Advances.

https://advances.sciencemag.org/content/5/10/eaax2805.

This proves that Extreme Biomimetics opens up new research perspectives and creates new values in science.

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