Characterization and modelling of structure and transport properties of porous ceramics

Abstract

It is well known, that ceramics having a wide scale of porous morphologies are used in many different applications such as bio-ceramics, chemical engineering, exhaust gas treatment, fi ltration etc. [1, 2]. Porous systems ranging from an entirely open pore network e.g. for catalyst supports to entirely closed pore structures e.g. for insulation materials exist. The application of such porous ceramic systems is quite often connected to specifi c transport properties, e.g. fl ow of media in fi ltration, ion conductivity in electrochemical membranes or thermal conductivity in insulation materials. All these transport properties are known for bulk and dense materials but in case of biphasic materials (bulk and pores) such properties could be calculated only if the geometry of the biphasic material is known in detail. On the other hand, ceramic engineering methods provide different routes to tailor porosity and microstructure to a certain degree. Typical methods to produce and to adjust porosity are partial sintering, use of pore formers or templates, foaming, freezing or size exclusion of particles. Typical development schemes involve preparation of sets of samples and measurement of the resulting properties. By optimisation strategies, sometimes supported by “design of experiment” methodologies, the target properties can be reached. By employing a strategy of model generation and virtual material testing this process might be signifi cantly optimised. Fig. 1 shows a general scheme of development cycles, which involve different stages of Characterization and Modelling of Structure and Transport Properties of Porous Ceramics