Smart materials: foams, gels and microcapsules
September 26 - 28, 2005, Aachen, Germany
Paper
Characterization of porous bead celluloses by analytical centrifugation
T. Sobisch and D. Lerche
L. U.M. GmbH, Rudower Chaussee 29 (OWZ) 12489 Berlin / Germany
e-mail info@lum-gmbh.de, www.lum-gmbh.com
S. Fischer, C. Fanter
Fraunhofer IAP Geiselbergstr. 69 14476 Potsdam-Golm
Porous bead celluloses have wide ranging potential applications as separation media and carrier systems in the field of pharmacy and foods. Physicochemical characterization of these materials and related suspensions is essential for quality control and technical applications. This includes their surface properties, porosities and mechanical properties.
The paper describes the application of multisample analytical centrifugation for porous bead celluloses allowing a qualitative and quantitative characterization.
The method traces the distribution of light transmission over the whole sample length during centrifugation. Thereby the kinetics and extent of separation processes can be investigated in-situ.
Bead cellulose is regenerated spherical porous cellulose, manufactured by a special dispersing method starting from different cellulose derivatives. Such samples of different sizes and differing in the preparation process were chosen and analysed in respect to porosity, surface, morphology and particle size distribution.
The consolidation, packing behaviour and elasticity of the bead celluloses was analysed in an alternating centrifugal field.
Differences in packing density obtained under controlled conditions were related to the porosities of the samples. Different preparation processes lead to an alteration of the surface properties of the bead celluloses.
Further bead celluloses revealed a markedly different behaviour than cellulose powder manufactured from native cellulose.
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