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Homemade Ferrofluid

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LAN_403

Part Scavenger

Tue Feb 28 2006, 03:22AM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

Thanks for replying!
Do you have a sis?

Nah, um, have you seen this?

A couple of people on there seem to know what they're doing. The "Caver" guy claims to have make "spikey" ferrofluid at home, and recommends filtering the homemade ferrofluid.

Have you tried the tetra..whatever hydroxide as a carrier? I saw another couple of sites use it. Several places said the amount of carrier fluid was important to spikes. How do you know what this is? Is it just what sticks to the magnetite or if you have too much is that bad?

Oh, and thanks for the pdf! I haven't seen that one yet. I wonder what the ONE DROP or less does to enhance the spikes...

...

Tue Feb 28 2006, 03:27AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

welcome to the forum!

Here is a lab procedure for making it... There are a few diagrams there, and the procedure seems simpler; might be worth a try...

Good Luck!

Heiders

Tue Feb 28 2006, 04:26AM

Registered Member #268 Joined: Tue Feb 28 2006, 02:44AM
Location: Ontario, Canada
Posts: 48

Two sisters, both taken.

First I've seen of that thread. Thanks! No, I haven't used that tetra-something hydroxide as a carrier.

I actually split the latest batch into 2 parts, separated before cooking. After cooking, I added the amount of kerosene called for in the instructions to one portion. Results: Just blobby on the sides, no spikes.

To the second, I added about 25mL of kerosene, instead of 100mL. There were more clumps left, but I'm going to filter it now. What amounts have you tried?

What are you using to hold it? I have it in a not-very-watertight glass spice jar with some electrical tape. I'm wondering if it is too thick (either glass or fluid) to respond to the magnet properly, though I can drag it up the side no problem. I might be able to get a petri dish from the previously-mentioned chem teacher... Might that help?

I used lemon-scented yellow ammonia. What did you use? The thread you referenced said "no colours or scents" so I'm not sure.

Yes, I have seen the procedure from UCLA but it used a different surfactant. I'm not too sure whether rinsing it will work, and/or how much you lose per rinse. Could be interesting to see where to get the tetramethylammonium hydroxide and ammonium hydroxide, though. Good stuff.

Mike

Tue Feb 28 2006, 05:59AM

Registered Member #58 Joined: Thu Feb 09 2006, 05:40AM
Location: Tri-Cities, Washington, US
Posts: 317

Well regular ammonia is in many household cleaners, however ammonium hydroxide (NH4OH) is in many Industrial Cleaners. However there is no need to search for these. Ammonium Hydroxide has the ability to dissociate in water so, NH3 + H2O â‡Œ NH4+ + OH-
It is the name given to an aqueous solution of Ammonia. So you should be able to create your own.

Bored Chemist

Tue Feb 28 2006, 06:18PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

"I know. It's 83% oleic acid according to my friend who is a chem teacher and a pharmacist I talked to."
This is true in the same way that salt is about 64%chlorine- that doesn't mean that roughly 2/3 of it escapes from the salt cellar as a green gas.

I wouldn't do all the messing about with lead compounds as given in that article (There are errors in it anyway). Since all you need is a surfactant then the mixture of fatty acids from olive oil would probably do. If you want I will sort out a method for getting this.

Ammonium hydroxide very nearly doesn't exist. ammonia disolves in water- very little of it get's ionised.
I'm not sure about getting hold of quaternary ammonium compounds - a few get used as bactericides and IIRC "bitrex"- the denaturant used in some alcohol is another example. That's no guarantee that they would work in this case.

Part Scavenger

Tue Feb 28 2006, 06:48PM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

I wasn't planning on messing with that lead stuff anyway, but thanks for the concern. You're right about the oleic acid in the olive oil, but couldn't I "pull it out"? I plan to look into the soapmaking stuff, apparently you can add HCl to olive oil and do something else to get the pure-ish oleic acid. I borrowed a book from my chem friend today that I believe will tell me how to do it, but I won't have time to do anything with it until Friday probably. Am I headed the right direction with the HCl and soapmaking process?

UPDATE: Ok, I think I figured it out. Here's what I plan to do:

1 Hydrolyze the olive oil using HCl in the form of muratic acid.
2. Ok, so now Iâ€™ve got excess HCl, glycerol, and fatty acids most of which are oleic acid carboxylic chains?
3. Then how do I get rid of everything except the fatty acids? Do they just dissolve in the water and pour off? This seems right because glycerol is soluble in water, as is HCl. That would mean I now have a mixture of carboxylic acids that is something like 83% oleic acid and a couple of other fatty acids that look like theyâ€™d do the same job.

Water is needed for hydrolysis, but do I need to add any because that's what muratic acid is already, right? Still I might need to add water?

And how do I figure out how much of each I need? I know it has to do with the molecular weight and the ratio of the way they bond, but VOLUME doesnâ€™t seem to matter. It has to do with the concentration. Can I just dump it together? The â€œextraâ€ stuff would be all soluable in water I think, so it should just pour off right? That way I wouldnâ€™t have to do titration to figure out the amounts I need.

In response to Heidi, I think I'm getting the same stuff you are. Your description is almost exactly the same as mine looks.

I'm using super-grande, bottom of the shelf, good old sinus openin' ammonia. I read to buy it cheap because scents and flavors(or lack thereof) could interfere. That's good for me because my family uses the cheapest they sell.

I'm holding it in a glass baby-food jar, but it coats the inside with a black mess. It doesn't do that in a peanut butter jar though. I guess it likes the glass. I don't figure that that would happen as much if the ferrofluid was made properly, but I've never had the real stuff, so I don't know. I didn't keep it in there because one time I left acetone in a PB like jar... Didn't know about kerosene.

I filtered it last night through some T-shirt (redneck filter paper), and it got much smoother, still no spikes. Keep in mind I made this ferrofluid the horribly wrong way, so it might not reflect your results. I plan to make a new batch asaic.

Kerosene. Um, 100mL and "dump it in and see"

Off to take a speech test... Yippie. Sigh... I can't wait to take micro or something stimulating.

ANOTHER UPDATE: After my speech test, I ran to the shop to get my notes for my Philosophy test. While I was there I poured some muratic acid, and distilled water into some olive oil and swirled it up. At first I thought nothing was happening, but then the bubbles on the bottom of the olive oil started puffing into the water/HCl below. After letting it settle, I now have three layers. One is the bottom watery layer, a opaque-ish pee yellow thick substance, and a translucent or clear (haven't decided, it hasn't completely settled out.)

I'm pretty sure the middle layer is fatty acids, the bottom is the water and the other stuff, and heck if I know what the top layer is. (getting clearer) It's thin, but not quite as thin as water. Glycerin/glycerol? Got me. I thought that stuff would dissolve in the bottom layer. Anybody know? Is the yellow stuff what I think it is?

Oh, and the yellow stuff is pretty smooth and opaque. The original olive oil was slightly greenish and transparent. It did something!

Be back after my other test...

Bored Chemist

Wed Mar 01 2006, 07:52PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

Acid hydrolysis of the oil will work but it's slow.
If you have a book on soapmaking that's a good start. Make soap from some olive oil- no colour no perfumes of course.
Most soap making methods I have seen add lots of salt to the hydrolysed fat to precipitate the soap. Don't bother with that- just add the HCl at that point. The oleic (and other) acids will come out of solution- they don't disolve in water. You can tell when you have enough acid because when all the soap is used up the stuff isn't bubbly any more (well it's a lot less bubbly). Pure oleic acid is liquid at room temp so cool the resulting mess in the fridge (if it settles out into 2 layers then it's the top stuff you want. You may be able to pour it off and save fridge space) filter it quickly- paper towels usually work quite well. The next thing is to wash it to get rid of other junk- HCl glycerine etc so mix it with hot water. It should settle down into 2 layers; again you want the top one. The easy way to get this is to put it in a screw top jar, turn it upside down then put it back in the fridge. The acid goes solid so you can open the jar and let the water out (from under it). That should give you a fairly clean sample of oleic acid. The biggest impurity in it will be water (which doesn't really matter here).

Part Scavenger

Thu Mar 02 2006, 01:33AM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

Thank You!!! I really appreciate it! I will try it as soon as I can. I love this forum.

Omicron

Thu Mar 02 2006, 02:10AM

Registered Member #131 Joined: Fri Feb 10 2006, 09:25PM
Location:
Posts: 185

Why not just buy it? Its pretty cheap, and I have made ferrofluid before try using a technical grade oleic acid.

Heiders

Thu Mar 02 2006, 04:01AM

Registered Member #268 Joined: Tue Feb 28 2006, 02:44AM
Location: Ontario, Canada
Posts: 48

It's not cheap! I paid about $40 CDN for 1 gal (about 4L) and couldn't get a smaller size. *edit* I was referring to oleic here, sorry. I thought you were too! */edit*

Great layers Part Scavenger! I have a waste jar because I'm not too sure what I can pour down my drain, it has layers like that from all the crap I poured in there. It's neat.

Also: I respect you for wanting the fun of making your own oleic. Good luck *laughs*

I am attempting to filter mine through proper filer paper, but im losing so much to the paper and the rest to evaporation, it has been sitting 48hrs now (laziness and lack of chance to get at it again, but I checked it before school this AM) and still isnt all the way filtered. I did cover the whole unit with plastic wrap and it's in a cool dark area to limit evaporation, but still.

I'm going to transfer it to a new filter paper and see what happens.

Mostly I have seen ammonia as blue (windex) or yellow (household cleaner). What colour is it really? Clear? Google was unhelpful...

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