Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Characterization of highly porous materials from cellulose carbamate

: Pinnow, M.; Fink, H.-P.; Fanter, C.; Kunze, J.


Heinze, T. ; Verein der Zellstoff- und Papier-Chemiker und -Ingenieure:
Structure and properties of cellulose : Selected contributions from the conference in Wiesbaden (Germany), June 26-28, 2007
Weinheim: Wiley-VCH, 2008 (Macromolecular symposia 262.2008, Nr.1)
ISSN: 0258-0322
Verein der Zellstoff- und Papierchemiker und -ingenieure (Annual Meeting) <2007, Wiesbaden>
Konferenzbeitrag, Zeitschriftenaufsatz
Fraunhofer IAP ()

Highly porous cellulose was formed by gelation of cellulose carbamate solutions in caustic soda. Two methods for gel preparation were optimized for the formation of beads and bulky materials - the chemical precipitation from dilute sulfuric acid and the thermal gelation by annealing at elevated temperatures. Various methods were used for characterizing of the pores of low density materials: scanning electron microscopy, small angle X-ray scattering, mercury intrusion and nitrogen sorption. These methods were optimized and used for characterizing the complete pore system from micro to macro pores. The effects of different preparation (cellulose carbamate concentration in caustic soda) and processing (precipitation, drying and pyrolysis) on the pore structure were studied by the set of complementary methods. Aerocell samples with a minimum density of 0.06 g/cm3 were prepared from cellulose carbamate. They are characterized by a broad pore size distribution ranging from 0.5 nm to 1 mm, specific internal surfaces of up to 660 m2/g and total pore volumes of up to 18 cm3/g.