emulsions.ppt - Emulsions Emulsions \u2022 An emulsion consists of two immiscible liquids one of which is uniformly dispersed throughout the other as fine

emulsions.ppt - Emulsions Emulsions • An emulsion...

This preview shows page 1 - 6 out of 16 pages.

Emulsions
Image of page 1
Emulsions An emulsion consists of two immiscible liquids, one of which is uniformly dispersed throughout the other as fine droplets normally of diameter 0.1-100 µm. 2 phases: Disperse or internal phase Continuous or external phase.
Image of page 2
Examples of Emulsions Oil and water mixtures are emulsions when shaken together. The oil will form drops and disperse throughout the water. Egg yolk is an emulsion containing the emulsifying agent lecithin. Crema on espresso is an emulsion consisting of water and coffee oil. Butter is an emulsion of water in fat. Mayonnaise is an oil in water emulsion that is stabilized by the lecithin in egg yolk.
Image of page 3
Emulsion types o/w emulsions. w/o emulsions. Multiple emulsions (e.g. w/o/w or o/w/o).
Image of page 4
Identification of emulsion type Miscibility test : An emulsion will only mix with a liquid that is miscible with its continuous phase. Therefore an o/w emulsion is miscible with water. a w/o emulsion with an oil. Conductivity measurement : Systems with an aqueous continuous phase will conduct electricity, whilst systems with an oily continuous phase will not. Dye test : If an oil-soluble dye is used, o/w emulsions are pale in colour than w/o emulsions and vice versa. If examined microscopically. an o/w emulsion will appear as coloured globules on a colourless background whilst a w/o emulsion will appear as colourless globules against a coloured background.
Image of page 5
Image of page 6

You've reached the end of your free preview.

Want to read all 16 pages?

  • Fall '15
  • MrRosdi
  • Emulsion

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes