Sciencemadness Discussion Board


ahlok2002 - 24-3-2005 at 03:15

Hi everyone here.

i would like to ask what is the best emulsifier for emulsion oil water in oil?

actually i have try to do emulsion with some commercial emulsifier yet the emulsion seems no very stable in the sense of not stable to heat test. ( i incubate the emulsion in 100oC for 30 minutes). the crystal form on the surface. so i would like to ask what may be the cause of the crystal formation. can it be due to the low boiling point? (because i did add diesel to reduce the viscosity of the mineral oil that i used as the oil phase).

Another thing is the water test. the emulsion will again immense into the water and the water turn cloudy and some polar particle that mixed with the emulsion come out to water phase and dilute to the water. Actually i would like to avoid the polar particle remain into the emulsion without mixed with water.
for this reason , i would suspect the acidity of the water may cause the instability of the emulsion. or the emulsifier used not enough.

i would like to listen to any advice. Thanks

chemoleo - 24-3-2005 at 06:35

Lecithin is a wellknown emulsifier (it is a phospholipid), and available from vitamin suppliers etc, and commonly used in the food industry for emulsions.

In principle, most amphiphatic compounds are good emulisifiers (molecules with both polar and unpolar/hydrophobic elements). For instance, protiens are good emulsifiers, this is partially observed with milk.
Detergents of any kind are equally good emulsifiers.

sparkgap - 27-3-2005 at 09:07

Eggwhite and soap come to mind as stuff that can make oil and water mix.

sparky (^_^)

mick - 27-3-2005 at 15:58

Corn flower mixed cold with water and added to some hot stuff should make a nice emulsion.
It works for making a curry masala

Darkblade48 - 27-3-2005 at 17:46

Originally posted by sparkgap
Eggwhite and soap come to mind as stuff that can make oil and water mix.

sparky (^_^)

Aren't eggwhites used to make mayonaise as well? Tasty *yum*

sparkgap - 27-3-2005 at 18:40

Mayonnaise happens to be an emulsion of vinegar and oil, with eggwhite as emulsifier. :D

sparky (^_^)

ahlok2002 - 5-9-2005 at 00:37

. thanks guys...

but what my emulsion is water in oil (W/O) system...the emulsifier suggested above is more likely work reverse with my system. Emulsifier works well in the W/O system has HLB (hydrophilic- lipophilic balance) value lower than 6. However, emulsifier works in the O/W system will have HLB value higher than 7 and above. commercial detergents and soaps are emulsifiers with HLB higher than 6...which work totally reverse in my W/O system. that we use them as "de-emulsifier" to break down the W/O emulsion.

i'm interested in two types of emulsifier. the SMO( sorbitol mono-olate) and PIBSA (polyisobutylene succinate anhydride).

i'm finding a best way to synthesis the PIBSA in laboratory. i want to cap the PIBSA with amine, ester or sugar. i still looking for suitable "head" to cap. i heard one of the technique so called lactonization....which can provide a better caped PIBSA..anyone familiar with this synthesis. i wish to listen to any comment. thanks