Cellulose as a novel amphiphilic coating for oil-in-water and water-in-oil dispersions.
The amphiphilic character of cellulose molecules provides the opportunity to use it as a novel eco-friendly emulsifying agent for formation of stable oil-in-water or water-in-oil dispersions. This may be done by mixing water, oil and cellulose solution in an ionic liquid. A more practical alternative is to form first a hydrogel from the cellulose/ionic liquid solution by coagulation with water and applying it into the sonicated water/oil or oil/water mixtures. The dissolution/regeneration process affords higher mobility to the cellulose molecules so an encapsulating coating can be formed at the water-oil interface. A solid-state dispersion was obtained by drying liquid dispersions, which can be repeatedly dissolved in excess water reforming a sustainable dispersion. The damp dispersion can be blown under reduced pressure, yielding a nanoporous foam ("aerocellulose"). The n-eicosane based solid dispersion as well as the aqueous dispersion possess a very high effective heat-absorption capacity. X-ray diffraction patterns indicate that the encapsulating cellulose shell is indeed in the amorphous state. Small-angle diffraction patterns of n-eicosane dispersions exhibit two sharp reflections. One is due to the n-eicosane triclinic crystal bulk phase and the other at somewhat smaller angles is interpreted as due to less ordered phase, possibly due to interactions with the encapsulating cellulose.
Department of Chemical Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel. cerycdr@tx.technion.ac.il
Dmitry M
DM
Rein
Rafail
R
Khalfin
Yachin
Y
Cohen