Nanoemulsion is known to be thermodynamically unstable. But till what temperature will it remain constant? Does the stability depend on constituent or surfactant or mode external energy applied?
below the cloud point of surfactant. carry out your study at 10 degree celsius increment but below the cloud point.
Dear Bhatt,
Thanks for the answer. Let me try as per your suggestion. But I need a clarification. A solvent/surfactant's cloud point does not remain the same when in solution. So, how do I find the cloud point of each phase I have added in the solution. I will be adding oil, water extract, surfactant and co-surfactant.
Thanks in advance
Tell me which surfactants you are using?
Cloud points are characteristic of nonionic surfactants. Anionic surfactants (with negatively charged groups) are more water-soluble than nonionic surfactants and will typically have much higher cloud points (above 100°C). The presence of other components in a formulation can depress or increase the solution's cloud point.
Method:
For determining cloud point, plate heater provided with a test tube can be used. Initially prepare a 50 ml stock solution containing 100 millimoles of surfactant. From the
prepared stock solution, make solution of different concentration ranging from 10
millimoles to 30 millimoles . For each concentration, the cloud point is determined
with help of plate heater. Place the Beaker filled with water on the plate heater. After
the setup is arranged, place the test tube containing the prepared solution and start heating. Controlled heating is done, starting from the room temperature at a rate of
0.3 degree C/min till the required cloud point temperature is obtained. Cloud point
temperature of surfactant solutions is determined by the visual examination of the
abrupt change in the appearance of the surfactant solutions as it occurs during the
heating of the sample solutions.
Dear Himanshu,
Thanks for the methodology. Am trying your suggested method
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