Emulsions Stabilized Using HMI

Emulsions of Isopar M/water and cyclomethicone/water were prepared using HMI. The 50/50 v/v O/W emulsions were prepared and the emulsifier concentration was varied from 0.25 to 2.0% w/v based on the oil phase. The 0.5% w/v emulsifier was sufficient for stabiUzation of these 50/50 v/v emulsions [12]. 

The emulsions were stored at room temperature and 50 °C and optical micrographs were taken at intervals of time (for one year) in order to check the stability. Emulsions prepared in water were very stable, showing no change in droplet size distribution over 

No change in droplet size was observed after storage for more than one year at 50 °C, indicating the absence of coalescence. The same result was obtained when using different oils. Emulsions were also stable against coalescence in the presence of high electrolyte concentrations (up to 4 mol/dm or 25% NaCl). 

The above stability in high electrolyte concentrations is not observed with polymeric surfactants based on polyethylene oxide (PEO). The high stability observed using HMI 

Solutions of PEO 4000 and 20000 showed a systematic decrease of cloud point with an increase in NaCl or MgS04 concentration. In contrast, inulin showed no cloud point up to 4mol/dm NaCl and up to 1 mol/dm MgS04. 

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