Synthesis of Porous Emulsion-Templated Monoliths Using a Low-Energy Emulsification Batch Mixer
Résumé
Emulsion-templated porous monoliths based on castor oil-in-black liquor emulsions have been prepared using a low-energy emulsification technique. Lignins from black liquor polymerize in the continuous phase of the high internal phase emulsion to obtain highly microcellular materials with interconnected open porous structures. A two-step emulsification operating mode was developed in order to increase the maximum value of the castor-oil dispersed volume fraction obtained with the one-step emulsification mode (limited to 53 % of the total emulsion volume due to the very high viscosities of the fluids). A rheological study of the black liquor and of the prepared Medium Internal Phase Emulsions, have been conducted. Depending on the emulsification operating mode used, the morphology of the porous monoliths will differ. A rather low mean droplet size (about 6 μm) is obtained with the one-step mode, the two-step technique leads to a broader void size distribution and a further increase of added castor oil (up to 69 %) do not favor the homogeneity of the material. © 2013 Springer Science+Business Media New York.
Mots clés
High internal phase emulsions
Kraft black liquor
Low-energy emulsifications
Microcellular materials
Porous morphology
Rheological property
Rheological studies
Void size distribution
Kraft process
Monolithic integrated circuits
Morphology
Vegetable oils
Emulsification
emulsion
lignin
polymerization
porosity
rheology