Characterization of Porous Bead Celluloses by Analytical Centrifugation

摘要

Porous bead celluloses have wide ranging applications as separation media and carrier systems. 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. Bead celluloses of different sizes and differing in the preparation process were chosen and analysed in respect to porosity and particle interactions. 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 used to calculate the porosities of the samples. Multisample analytical centrifugation provides a powerful alternative for determination of the cumulative porosity, which was elaborated in this study. This approach is generally applicable for other particulate material if strong flocculation between particles can be avoided. Further, different preparation processes lead to an alteration of the surface properties of the bead celluloses. Bead celluloses revealed a markedly different behaviour than cellulose powder manufactured from native cellulose.