Additives XIII: EMULSIFICATION and DEMULSIFICATION

[MolaKule]

What is the difference between the process of EMULSIFICATION and DEMULSIFICATION?

List one or more additives for each.

[ July 21, 2003, 07:20 PM: Message edited by: Patman ]

 

[Pablo]

emulsify - to bring two or more (liquid) components that normally are not soluble in/with each other together - to form a another "liquid" or suspended solution. An example would be a calcium soap like compound with the Ca+ charge on one end and a hydrocarbon on the other end capturing a (-) charged compound

demulsify - to break apart a suspended solution into it's component parts, a detergent or even some esters would do this.

 

[Pablo]

Came to see if any one on crack...I mean if anyone took a crack at this one. Guess not.

I made a FEW errors:

First - I wrote: "demulsify - to break apart a suspended solution into it's component parts, a detergent or even some esters would do this." PLEASE exchange the word dispersant for detergent - I was just typing.

Second - examples:

E = calcium sulfonates (which is a detergent)
D = alkylsuccinic ester

 

[MolaKule]

Way to go, Pablo!

In terms of additives, an emulsifier additive promotes the formation of a "stable" mixture or 'emulsion,' say, of oil and water. Many gear lubes do this so that water will not form droplets on steel surfaces.

If you have ever changed a diffy that has been subjected to water intrusion or lots of moisture, you will see a yellow-ish or almost creamy-white mixture when being drained. This is an emulsion of water and oil. Hopefully, the other additives have protected the surfaces from rust and corrosion while the water is in suspension. The carboxylic esters of alkenyl's and the polyisobutylene succininates help to emulsify the water. Sometimes they come packaged with a corrosion inhibitor, a rust inhibitor, and wetting agents (surfactants). Wetting agents here do not refer to water wetting, but the action of chemicals to spread or climb on surfaces.

On the other end of the sprectrum, there are chemicals that "demulsify" or separate water from oil. And the "demulsifiability" of a fluid is its ability to separate from water. The demulsifier additives are the carboxylic esters of hydroxyalkyl and others. Sometimes they come packaged with a corrosion inhibitor, a rust inhibitor, and a dispersant.

[ July 21, 2003, 05:21 PM: Message edited by: MolaKule ]

 

[MolaKule]

Here is some more info on emulsifiers:

An emulsifier is a surface-active agent that facilitates the mixing of two or more liquid substances that would separate into its component parts under normal conditions. Soap, for example, can act as an emulsifier.


The Two Ends of the molecule:
An emulsifier is a substance that has two ends--one oil-attracting end (hydrophobic) and one water-attracting (hydrophilic) end.


Mixing Oil and Water:
An emulsifier makes it possible for oil and water to stay mixed together. When mixed in a container with both water and oil, the emulsifier binds the oil to one of its ends and the water to the opposite end.


Chemical Emulsifiers
Once solvents dissolve oil-based chemical products, emulsifiers are then used to make these dissolved chemicals mix in an aqueous solution. Chemical emulsifiers are complex, synthetic liquids formulated for their specific functions.


Food Grade Types
Several types of food grade emulsifiers include lecithin, agar, locust bean gum, carrageenan and gum arabic, all of which are commonly processed food ingredients.

 

[MolaKule]

Question:

In marine gear lubes, a bit more emulsifier is added.

Why would you want moisture to be mixed with oil in a gearbox?

 

[ramechanic4]

I'm going to say it's a trick question, or at the very least, backwards.

To answer your question:
Why would you want moisture to be mixed with oil in a gearbox? You wouldn't WANT water mixed with the oil.

But in marine gearboxes, it is assumed water will be present at some point, so re-word it to:
Why wouldn't you want oil mixed with the water in your marine gearbox?
And I think the answer presents itself!

Just my opinion, it's worth what you paid for it.

 

[ramechanic4]

Just went back and read the first part of this post, where you already answered "my" version of the question.

Originally Posted By: MolaKule


In terms of additives, an emulsifier additive promotes the formation of a "stable" mixture or 'emulsion,' say, of oil and water. Many gear lubes do this so that water will not form droplets on steel surfaces.

 

[MolaKule]

Well done ramechanic4.

Yes, I wanted to see if people might apply that statment to marine gear lubes as well.

You don't want droplets forming on steel surfaces or they will rust.

A stable emulsion prevents this from happenning.