Quantitative composition determination of »water-in-oil« emulsions using thermal techniques
Schematic model representing emulsion composition. Circles represent supersaturated water solution of ammonium nitrate; the droplet size is approximately 1 μm while grey area between them represent an oil/emulsifier phase with a thickness ranging from 3 to nm.
DSC cycling experiment of “water-in-oil” emulsion . On repeated scans ammonium nitrate (AN) begins to crystallize. From the enthaply of crystallization peak (positioned at 126 °C) the AN content was determined. For the accuracy of this determination it is necessary that the crucible was covered with 50 μm perforated lid. In the case crucibles were covered with larger hole, after water evaporation AN starts to evaporate (see TG cycling experiment below).
TG cycling experiment (10 heating and cooling cycles) of “water-in-oil” emulsion.