The authors would like to thank the German Research Foundation (DFG) for funding the Research Group FOR 583 “Solid Sponges – Application of monolithic network structures in process engineering.” Special thanks to Dr. Giesela Guthausen, Institute of Mechanical Process Engineering and Mechanics, KIT, and Julia Große, Institute of Thermal Process Engineering, KIT, for the substantial help with the 1H NMR measurements. Also, we would like to thank Mark Fresewinkel for supporting the authors in the experiments.
Preparation of Optically Transparent Open-Celled Foams and its Morphological Characterization Employing Volume Image Analysis†
Article first published online: 21 JUL 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Engineering Materials
Special Issue: Cellular Materials
Volume 13, Issue 11, pages 1060–1065, November 2011
How to Cite
Bucharsky, E. C., Schell, K. G., Habisreuther, P., Oberacker, R., Zarzalis, N. and Hoffmann, M. J. (2011), Preparation of Optically Transparent Open-Celled Foams and its Morphological Characterization Employing Volume Image Analysis. Adv. Eng. Mater., 13: 1060–1065. doi: 10.1002/adem.201100024
- Issue published online: 28 OCT 2011
- Article first published online: 21 JUL 2011
- Manuscript Revised: 3 JUN 2011
- Manuscript Received: 22 JAN 2011
Transparent glass sponges are a new class of materials that can potentially be used for effective light dispersion in photobioreactors. In this work, transparent glass sponges are prepared by the polymer replica technique employing polyurethane sponges with cell sizes of 20 pores per inch as templates and commercially available nanoscaled SiO2 powders. Necessary conditions for obtaining transparent open-celled glass sponges are presented. Topics such as slurry stabilization, temperature for burning-out the polymer and subsequent sintering of the remaining SiO2 structure to transparent cellular bodies are discussed. It was found, that concentrated suspensions at around pH 10 offer suitable properties for both, bringing enough particles onto the polymer template for the formation of a stable and self-supporting SiO2 shell and for successful sintering of the particulate framework to transparent bodies. Therefore, an adjusted burning-out process and an adequate sintering regime is presented. Furthermore, the resulting sponge structure is characterized employing X-Ray diffractometry, light, and scanning electron microscopy. In addition, volume image analysis was performed using magnetic resonance imaging. This method allows the calculation of geometrical parameters like cell-size and specific surface area of the resulting structure, required for application of the new material.