Status & Perspectives in Science & Education

67 66 Principal Scientist Profiles Delia Brauer Delia Brauer Principal Scientist Profiles PROFESSOR OF BIOACTIVE GLASSES Delia Brauer is Professor of Bioactive Glasses. She is a Fellow of the Society of Glass Technology and member of its Board of Fellows. She chairs Technical Committee 04 (Glasses as Biomaterials) of the International Commission on Glass (ICG) and is a member of the Basic Sciences and Technology Committee of the Society of Glass Technology. In 2015, she was awarded the Gottardi Prize of the International Commission on Glass (ICG), which is presented annually to a young person with outstanding achievements in the field of glass in research and development, teaching, writing, management or commerce. She is also a member of the Jena Center for Microbial Communication (JCMC). DELIA BRAUER RESEARCH AREAS Professor Brauer‘s research focuses on the materials chemistry of inorganic, non-metallic materials, especially glasses and glass-ceramics, with a particular focus on the interaction between materials and water. She is also interested in how glass composition, structure and properties are connected, particularly in glasses having a highly disrupted structure. Current research areas include: • Improving the hydrolytic stability of phosphate glasses • Glass-based cement systems • Bioactive glasses with improved processing • Morphology and topography of glass-ceramic surfaces • Synchrotron applications for glasses and glass-ceramics • Characterisation of archaeological glasses, glazes and ceramics • 3D-μCT in bioactive glass research TEACHING FIELDS Prof. Brauer teaches students of the courses Materials Science, Chemistry and Chemistry of Materials at the Bachelor and Master level. Her courses include: • General and inorganic chemistry • Materials science (courses on glass, ceramics, glass structure and ceramics in medicine) • Materials synthesis and characterization RESEARCH METHODS Prof. Brauer‘s research group prepares and characterizes glasses and glass-ceramics. Techniques include: • Equipment for glass melting • High-temperature characterization including DSC, heating microscopy, • Structural characterisation including x-ray diffraction, FTIR and Solid-State (MAS) NMR spectroscopy, 3D x-ray microscopy • Equipment for dissolution experiments and analysis RECENT RESEARCH RESULTS Bioactive Glasses Bioactive silicate glasses are used clinically to regenerate bone and as dentifrices to re-mineralize teeth. Prof. Brauer’s group investigates how glass structure controls ion release, dissolution and crystallisation; and how a structure-based glass design allows for optimisation of properties. Structure and mechanical properties of aluminosilicate glasses Aluminosilicate glasses are used for various applications where mechanical performance is key, e.g. as for mobile phone displays for fibres in glass fibre composites. We have shown that incorporation of phosphate, as an additional network former, offers unique opportunities for finetuning glass properties, e.g. elastic properties and hardness, via changes in glass structure and polymerization. [2] Surface crystallisation and topography As glasses are thermodynamically not stable, heat-treatment causes crystallization. Using a barium titanium silicate system as an example, we study the influence of atmosphere composition (moisture, air, argon or vacuum) on surface crystallisation of fresnoite crystals. 3D X-RAY MICROSCOPY IN MATERIALS RESEARCH With our new 3D-μCT (X-ray microscopy Xradia 620 Versa, Zeiss; jointly with the group of Applied Geology) it is possible to analyse both large items like archaeologically interesting ceramics (Figure A) or small items like a glass powder (Figure B). The technique allows for non-destructive analysis, being able to differentiate between phases of different density. Figure: (a) Upper part of an antique vase (16-17th century, Collegium Jenense): the white part is the preserved glazing, grey is the ceramic and the light dots are mainly quartz grains. The binding agent that was used to glue the individual shards together was numerically removed. (b) Glass powder (<0.125 mm): the challenge here was to prevent the particles from moving during rotation and to find a holder material that is X-ray transparent compared to the target material. Figure: LSM picture of fresnoite crystals on a glass surface with the crystals sinking into the bulk (blue is deep, red is the surface). [1] Wetzel et al., Sci. Rep. 10, 15964 (2020). [2] Grammes et al., Front. Mater. 7, 115 (2020). Contact: Phone: + 49 3641 9-48510 Email: delia.brauer@uni-jena.de

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