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.