This presentation is a review of the journal "Cristina.S, Sandu.P and Gheorghe.Z; Nature and Stabilityt of Liquid-Liquid Colloidal Systems Containing Safflower Oil, 2015, 60(1), 25-32."

1. COLLOIDS AND SURFACE
CHEMISTRY
LIQUID – LIQUID SYSTEMS
VIJAYA SUBRAMANIAM.P.R
M.E Environmental Engineering
Kumaraguru College of Technology,
Coimbatore.

2. LIQUID-LIQUID SYSTEM
• Colloidal systems involving dispersion of one liquid in other is called
emulsion.(both immiscible with each other) Eg: oil and water.
• Emulsions depend on the emulsifying agents for their stability.
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3. REFERENCE JOURNAL
• Cristina.S, Sandu.P and Gheorghe.Z; Nature and Stabilityt of Liquid-Liquid
Colloidal Systems Containing Safflower Oil, 2015, 60(1), 25-32.
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4. AIM OF THE RESEARCH
• To study the stability of the liquid –liquid colloidal system by dispersing the
safflower oil in sodium chloride solution, in the presence of a hydrophobic
surfactant (sorbitan monooleate).
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5. Why safflower oil?
• A type of semi-drying oils.
• It is a dietary oil & recommended for gastritis, liver disease and in early forms
of cardiovascular disease.
• Most valiant dietary oil in world market and its requirement is increased in
the last years due to its unsaturated fatty content.
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6. EXPERIMENT
MATERIALS:
Safflower oil, Sorbitan monooleate (Surfactant),
NaCl solution (0.2M, 0.4M, 0.6M, 0.8M, 1.0M)
OBTAINING OF COLLOIDS:
(i) Premix prepared by adding NaCl + Surfactant.
(ii) Then it is dispersed in oil, using mechanical
stirrer with speed of 1000 rpm for 5mins and 3500
rpm for 5mins.
CHARACTERIZATION OF VESICLE:
(i) The size, dimension determined by Motic
Microscope.
(ii) Diameter and size distribution found by
Dynamic Light Scattering. 6

7. PROCESS
• Premix (NaCl + surfactant) has a monodisperse appearance – observed by
Optical Microscope.
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8. • By the dispersion of premix in oil at a speed of 1000 rpm, double and
multiple emulsions are obtained in less proportion.
• The presence of vesicle is indicated by the wall thickness of dispersed
droplets is equal to the thickness of parallel superimposed layers of
surfactants.
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9. • While dispersion of premix in oil at 1000 rpm, if the concentration of salt in
aqueous phase is low (0.2M – 0.4M); monolayer vesicles are obtained.
• If the concentration is high (0.8M – 1.0M); multilayered vesicles are
obtained.
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10. • If the dispersion of premix in the oil is carried out by vigorous stirring at 3500
rpm; monolayer vesicles are obtained, irrespective of NaCl concentration.
• At 3500 rpm, the dispersed vesicles are smaller compared to those obtained
by mild agitation.
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11. • The intensity of shearing process has no effect on the formation of colloids if
the concentration of aqueous phase is intermediate (0.6M), the size of vesicle
obtained is small.
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12. • Colloidal droplets changes their appearance in time, if disperse system is
obtained by moderate shear.
• If the concentration of NaCl is higher, vesicles do not change its size but
multi layer vesicles becomes mono layers.
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13. • Dilute solutions of NaCl, growth of vesicles is observed in time (by
coalescence).
• The monolayers starts destabilization, and the colloidal system is converted to
emulsion. (from particle size analysis – 5micrometer)
• Separation of phases is slow in more than one month.
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14. • Dispersed system obtained by high speed stirring, rapid destabilization takes
place (immediate separation of phases within one day)
• The particle size is 1nm.
• This shows that the colloids prepared by high speed stirring are less stable.
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