THE STRUCTURE ELUCIDATION OF SEMISOLID W O EMULSION SYSTEMS CONTAINING SILICONE SURFACTANT/

In the course of investigating the effects of silicone surfactant (Abi l WE 09(R)) on the microstructure of semisolid w/o emulsion systems wi th different water/oil ratios, only dispersed droplets of the internal water phase (1-15 mu m size) were discovered in the gel network of wh ite petrolatum. With increasing water content (from 40 to 90% w/w) the degree of dispersity was found to increase (microscopic analysis-pola rized light microscopy and TEM). Experiments were also carried out usi ng differential scanning calorimetry (DSC) and rheometry (rotational a nd oscillatory viscosimetry). The DSC results showed different behavio ur of the investigated systems on controlled cooling. In semisolid emu lsion systems with droplets small enough and of equal size, a homogene ous nucleation temperature was achieved. In emulsion systems containin g a high percentage of water, the assumption that the behaviour of wat er was like that of the pure (bulk) water was acceptable. All semisoli d emulsion systems exhibited pseudoplastic behaviour. Their viscoelast ic properties determined using oscillation rheometry correlated well w ith rotational results.