Title of article :
Microstructural behavior of water-in-oil emulsions stabilized by fatty acid esters of propylene glycol and zinc fatty acid salts
Author/Authors :
Adam Macierzanka، نويسنده , , Adam and Szel?g، نويسنده , , Halina، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
13
From page :
125
To page :
137
Abstract :
This manuscript reports an experimental work to observe the microscopic structures and dispersion phase behavior of mixtures of water and oil with combined use of acylpropyleneglycols, containing C16/C18 fatty acid moiety, and zinc fatty acid carboxylates (ZnC), both of which play emulsifying roles in the water-in-oil (W/O) emulsion systems obtained. Attention was mostly paid to the effects of in situ crystallization of acylpropyleneglycols on emulsion phase behavior during the emulsification processes. found that the crystallization of acylpropyleneglycols (at about 40 °C) produced a sudden flocculation of water droplets. Continuous emulsification led, at lower temperatures, to (i) shear-induced deflocculation and the formation of a stable W/O emulsion, or (ii) a disruption of droplets and the separation of the water phase, depending on the relative concentrations of water against oil phase. Microscopic observations with confocal laser scanning microscope (CLSM) and differential interference contrast (DIC) technique, light-scattering experiments and rheological measurements were done to examine the structural changes, stability, and viscoelastic properties of the emulsions. Interfacial crystallization as well as the formation of a three-dimensional network of acylpropyleneglycols in the continuous oil phase determined the stability against coalescence and viscoelastic character of the emulsions. The rate of the structural transitions of the emulsions, observed during the emulsification, as well as differences in the rheological properties of the final emulsions, were dependent on the concentration of ZnC in the acylpropyleneglycol emulsifier. The yield stress values of the emulsions decreased consequently as the concentration of ZnC was increased.
Keywords :
Water-in-oil (W/O) emulsion microstructure , Interfacial crystallization , Propylene glycol fatty acid esters , Zinc carboxylates , rheology
Journal title :
Colloids and Surfaces A Physicochemical and Engineering Aspects
Serial Year :
2006
Journal title :
Colloids and Surfaces A Physicochemical and Engineering Aspects
Record number :
1792450
Link To Document :
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