Sciencemadness Discussion Board - Ferro Fluid surfactant

Ferro Fluid surfactant

CHRIS25 - 3-4-2014 at 13:44

Slight problem with acquiring TetraMethylAmmonium Hydroxide. Looking for a surfactant and I was wondering if vegetable oil would suffice? It is for making the magnetite particles in ferrofluid of equal charge so that they repel.

Steam - 3-4-2014 at 13:53

Some common surfactants for ferro fluid are Citric acid and oleic acid.
Remember that the surfactant must be soluble in the solvent!
I would recommend using a solution of ferric chloride and ammonia. Then add kerosene as an oil

Personally I have made ferro fluid from Magnetic ink developer (MICR) along with kerosene and oleic acid.

thesmug - 3-4-2014 at 14:26

Steam is exactly right. I've made it with oleic acid and it worked perfectly. Where did you see that suggested tetramethylammonium hydroxide!? That's a super obscure chemical that I've never seen used for this before, since oleic acid works well for this and is extremely easy to get.
Also, I suggest using a mixture of iron(II) chloride and iron(III) chloride when making your ferrofluid, that way you get almost completely iron(II,III) oxide.

CHRIS25 - 3-4-2014 at 15:57

Here is the link where I found the information. Thankyou for the tip about citric and oleic acid. I wonder if the amount of surfactant with these would be approximately the same as the video instruction?

http://www.youtube.com/watch?v=kPwIeoMFjJE

I know I will need to experiment but I wish to understand how the acid works on the Iron particles, what actually needs to occur to the molecules. If you have any references that I may turn to I would be pleased to read them. thankyou for your help.

thesmug - 3-4-2014 at 17:05

Another SciMad user MrHomescientist has this video which should help:
https://www.youtube.com/watch?v=LlQw9dfexBQ

CHRIS25 - 4-4-2014 at 08:04

Quote: Originally posted by thesmug

Another SciMad user MrHomescientist has this video which should help:
https://www.youtube.com/watch?v=LlQw9dfexBQ

Hi, I think that the instructions from the TechNyou video solve some of the problems that this guy encountered. Although his video was very good as well. I appreciate the pointer. I thought your American Kerosene was Petrol till I double checked, it is Paraffin where I come from. Good that I checked, I mean you call petrol gas and we call gas something that heats houses and food. Strange vocab there in USA....

blogfast25 - 4-4-2014 at 09:51

Oleic acid is fine, worked OK for me, even with homemade oleic acid.

CHRIS25 - 4-4-2014 at 12:30

Quote: Originally posted by blogfast25

Oleic acid is fine, worked OK for me, even with homemade oleic acid.

Did you make it according to wikpedia's method?

blogfast25 - 5-4-2014 at 02:49

Quote: Originally posted by CHRIS25

Did you make it according to wikpedia's method?

Saponification of olive oil with KOH, followed by hydrolysis of the soap with HCl. Separate out the crude oleic acid (it will contain other fatty acids too).

CHRIS25 - 6-4-2014 at 01:23

Quote: Originally posted by blogfast25

Quote: Originally posted by CHRIS25

Did you make it according to wikpedia's method?

Saponification of olive oil with KOH, followed by hydrolysis of the soap with HCl. Separate out the crude oleic acid (it will contain other fatty acids too).

My wife makes soap regularly, so you make saop with olive oil (Pecan oil has twice as much acid in it so this might be fun). I am sure that when you make soap this is actually hydrolysis in the first place? Why the HCl for a hydrolysis which has already taken place? I am only asking because I would like to do this instead of buying it, if I can.

deltaH - 6-4-2014 at 01:51

There is a 'high oleic' sunflower oil available in parts of the world. It's triolein component is generally rated above 80%

Expanding on what blogfast25 suggested, making soap using excess water (making slimes) and then acidifying/neutralising and simultaneously salting out the fatty acids with HCl sounds like a simple and good route to oleic acid! Should form two liquid phases. The organic layer should be rich in oleic acid if your starting oil was high in triolein.

[Edited on 6-4-2014 by deltaH]

blogfast25 - 6-4-2014 at 04:19

Quote: Originally posted by CHRIS25

The saponification is the hydrolysis of the triglyceride (the oil) to glycerine and soap (the K salts of the fatty acids).

To obtain the fatty acids, another hydrolysis is performed:

'Koleate' + HCl (in water) === > KCl (solution) + Oleic acid (insoluble in water)

Separating and drying yields crude oleic acid (containing also minor constituent fatty acids).

"Pecan oil has twice as much acid in it so this might be fun"

.... doesn't make much sense: all vegetable oils are triglycerides, so each mol of oil contains three mol of fatty acid. Now since as some fatty acids are much longer than others the total fatty acid content in w% does vary from one oil to another. So Pecan oil has three times the amount of fatty acid with respect to which other oil?

[Edited on 6-4-2014 by blogfast25]

CHRIS25 - 6-4-2014 at 06:27

Delta thankyou, I read about that sunflower oil, can not get it here though.

Blogfast I know you are more knowledgeable than me, so I appreciate the learning, I sourced the above infor mation from wikpedia and found other sites that suggested the following:
Triglycerides of oleic acid compose the majority of olive oil, although there may be less than 2.0% as free acid in the virgin olive oil, with higher concentrations making the olive oil inedible.[citation needed] It also makes up 59-75% of pecan oil,[3] 61% of canola oil,[4] 36-67% of peanut oil,[5] 60% of macadamia oil, 20-85% of sunflower oil (the latter in the high oleic variant),[6] 15-20% of grape seed oil, sea buckthorn oil, and sesame oil,[2] and 14% of poppyseed oil.[7] It is abundantly present in many animal fats, constituting 37 to 56% of chicken and turkey fat[8] and 44 to 47% of lard.

No doubt I may well be misunderstanding the chemistry here but I know next to nothing about fatty acids and organic chemistry Thankyou for the enlightenment by the way about the hydrolysis.

[Edited on 6-4-2014 by CHRIS25]
you introduced a new word, Koleate. Potassium oleate, never heard of it but it is the salt of oleic acid so where does the potassium come from? is this from the potassium hydroxide that used in making the first stage of the soap?

[Edited on 6-4-2014 by CHRIS25]

Steam - 6-4-2014 at 06:59

tetramethylammonium hydroxide is a phase transfer catalyst. n-methylammonium might work. I have some tertbutylammonium hexaflorophosphate which I have used for organic electrochemistry, but it is pricey so I am not going to use it for ferro fluid experiment.

If you want to try it with the n-methylammonium go ahead! You might have some interesting results for methylammonium is non polar where as the hydroxide is. This by definition is a surfactant.

The only problem is that the methyl groups are not very long so it might not be a very good surfactant. n-butylammonium or n-pentylammonium would be better options!

blogfast25 - 6-4-2014 at 07:31

Quote: Originally posted by CHRIS25

you introduced a new word, Koleate. Potassium oleate, never heard of it but it is the salt of oleic acid so where does the potassium come from? is this from the potassium hydroxide that used in making the first stage of the soap?

[Edited on 6-4-2014 by CHRIS25]

Sorry, 'Koleate' isn't really a word, it's clumsy, personal vernacular for potassium oleate, the potassium salt of oleic acid.

The oils have essentially the following structure:

CH<sub>2</sub>OOCR
|
CH-OOCR'
|
CH<sub>2</sub>OOCR"

Where R, R' and R" are hydrocarbon groups of the different fatty acids.

The left hand (vertical) chain is essentially glycerine (glycerol). The fatty acids are bound to it by ester bonds (the OOC group). When treated with KOH, the glycerine is 'liberated' by de-esterification (aka alkaline hydrolysis) and the salts of the fatty acids form: KOOCR. Salts of fatty acids are called soaps because old fashioned soaps are sodium or potassium salts of fatty acids.

[Edited on 6-4-2014 by blogfast25]

CHRIS25 - 6-4-2014 at 08:08

Oh that's clear, thankyou. Thankyou for your insight Blogfast.

HI Steam, well I'll be staying clear of those very long words

no experience at all in that sort of thing. Oleic acid will be the way I go but am glad for your comments.

CHRIS25 - 6-4-2014 at 10:25

My only question now is how do I know how much HCl to add. Even though I begin with a known amount of Olive oil and based on SAP values and KOH have an exact quantity of water, I now have produced an unknown amount of potassium oleate. I habe all the molecular weights sorted but unless I have a molecular weight for olive oil I will not know how many moles of CH(CH2)7CH=CH(CH2)7COOK I have produced which means I will not know how much HCl at 12M to add, is there such a thing as too much? I know too little would mean that I would fall short of optimum production but must there be exactness here?
[Edited on 6-4-2014 by CHRIS25]

[Edited on 6-4-2014 by CHRIS25]

thesmug - 6-4-2014 at 10:37

You do know you can delete posts in the edit screen?

CHRIS25 - 6-4-2014 at 10:51

Quote: Originally posted by thesmug

You do know you can delete posts in the edit screen?

Actually, no but now I do.