New Perspectives in Science Education

Silica-based materials offer a wide range of applications. While they’re being used as filters, coatings or as release agents in food manufacturing, especially mesoporous silica are object of intensive research in different scientific domains. Fabrication is based on a sol-gel process using micelles as templates for pores. The inorganic silica framework is responsible for a high thermal stability and provides various applications such as catalysis, material separation and gas storage.[1,2] Current research is therefore focusing on enhancing those traits by functionalizing the surface area, which led to the development of mesoporous silcones.

Due to their versatile properties, silicones can be found in many everyday products. While baking utensils and breast implants are more prominent examples, silicones are also being used as lubricants, as thermal or caulking compounds and in waterproofing treatments. On account of their useful properties such as thermal stability, resistance to weather, UV radiation, elasticity and flexibility, silicones are still of current interest in science research. Especially the recent use of microemulsions in templating procedures led to functional enhancements in monolithic materials with nanometer-range pores.[3]

In this contribution, we will present a teaching unit designed for schools and student laboratories, introducing basic concepts of material science on the example of silica and silicones. In addition to experiments demonstrating some of the characteristics of the above mentioned materials, the unit contains a simple synthesis of monolithic silicone as well as several experiments investigating some of its properties, such as thermal stability, hydrophobia and gas adsorption.[4]

In the course of this unit, students will encounter a number of topics consistent with curricular requirements. While the synthesis allows the revision and practice of reaction types such as hydrolysis and condensation, other chemical topics like surfactants and solubility can also be addressed.[1,5] Furthermore, these nonhazardous materials and chemicals allow high student participation during all experimental stages of the teaching unit.

References

[1] T. Wilke, S. Haffer, M. Tiemann, T. Waitz (2012). Mesoporöse Silica – Moderne Funktionsmaterialien im Chemieunterricht. CHEMKON 19/2, 67. [2] T. Wilke, S. Haffer, T. Waitz (2014). Silica-Based Nanomaterials in School Chemistry Education. New Perspective for Science Education, Conference Proceedings, Libreriauniversitatia.it, 87-92 [3] F. Hoffmann, M. Cornelius, J. Morell, M. Fröba (2006). Mesoporöse organisch-anorganische Hybridmaterialien auf Silicabasis. Angew. Chem. 118 (20), 3290. [4] T. Wilke, T. Waitz (2014). Funktionserweiterung durch Porosität - Herstellung und Eigenschaften eines porösen Silikon-schwamms, Chemkon, (accepted). [5] S. Nick, Z. Chomicz (2013). Zeolithe selbst gemacht! CHEMKON 20/1, 14.