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Making Ferrofluid

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I prety much stuck to the original instructions. The stuff you are seeing spiking was made by putting the magnet next to the container, moving it around so lots of magnetite would get attracted then pulling up the side of the container then pulling the magnet away a bit so most of the fluid spilled off. I then poured off the fluid that separated. Then I took the remainder and put it in a container of its own. I repeated this process several times because each time you do it, you only get a very small amount. So what Im working with is thick stuff.


Also I might mention that when boiling off the ammonia, it took a lot longer then 1 hour like the instructions said. I did it for about 2 hours and it still smells a tiny bit like ammonia. I think you might need to get most of it out to stop the precipitation. And I did find out why oleic acid was needed. Its because its not water soluble at all. for this recipe the surfactant needs to be oil soluble.

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  • 2 months later...

I've been using that recipie to make some ferrofluid for a school project. I've been having trouble at the stage where the ammonia is added. Namely, I don't know what color it is supposed to turn after I add the ammonia. I was under the impression that it was supposed to be black but all I'm getting is this muddy orange color. Any advice?


(by the way, how much FeCl3 are you using in the reaction with steel wool to FeCl2? With the advertised 10mL FeCl3 and 10 mL distilled with generous amounts of steel wool, it only takes me about 10 minutes to get it to the bright green color and a few more minutes until its the aqua color.)

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there is another method to produce magnetite that may be cheaper for some, and it looks like it could work.


basically I`v just made iron carbonate from mixing iron sulphate with washing soda (sodium carbonate) washing and filtering the ppt off and then drying it.

this will then be heated in a crucible to decompose into magnetite and carbon dioxide.


this looked an interesting read:


currently the carbonate is in the filter paper and drying right now, all being well I`ll do the heating tomorrow.


but considering that iron 2 sulphate can be bought at gardening centers as Moss Killer for lawns, and washing soda is also cheap and freely available, this May make another good alternative.

I have FeCl3 here as a solid but there`s no fun in that, also I read that NaOH (lye, caustic soda, sodium hydroxide) can be used in place of the ammonia.

so there`s 3 alternative routes now ;)




Ok ladies, as promised: http://www.scienceforums.net/forum/showthread.php?t=33495

Edited by YT2095
multiple post merged
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  • 6 months later...

I have been attempting ferrofluid synthesis for a few weeks now. Have experienced various results with a few different formulas. Most recently I have been using pcb etching solution as FeCl3 and going about the recipe usually discussed on the boards.


The closest thing to oleic acid I can get is a blend of omega oils, 3, 6, and 9.


I have two different forks in the road now before I go home and try this again.


One, I have definitely precipitated magnetite in the ferrous chloride solution. It it black and responds to a magnetic field. I let it sit with a container for 24 hours and a clear solution separated and sat on top. I extracted it with a syringe and separated it from the magnetite mixture. I assume that this is ammonia, possibly some water that was in the ferric chloride. It smells very heavily of ammonia. The black magnetite solids solution still has the smell of ammonia and I intend to cook It with the oleic acid blend.


This is part two. This is from a health food store. I intend to add 15 ml of this blend since it is about 30% oleic acid. The last time I tried this, I was left with a magnetic sludge. I wonder now whether I should add 15-20 ml of oil? The program calls for 5 ml oleic acid.


If anyone has any idea about what the clear liquid floating on top was, whether I should leave it in the mix before boiling( I figured I would be doing myself a favor by removing ammonia without boiling), or info about extracting oleic acid from a blend, should hit up this thread. I am looking forward to giving some video feedback here!!!

Edited by Powerstrip
Forgot something
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  • 2 weeks later...

Hi there...just a friendly reminder that if you are mixing chemicals that you need to wear gloves that are made to resist spills/drips. Also wear your protective eyewear....


The gloves that we use are nitrile and they will protect your hands from the chemicals.

(advertising link removed)

Edited by Phi for All
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  • 1 month later...

Bumping this thread again.



I have come closer to this goal, I still only get a mildly reactive blob.


Anyone capable of ferrofluid synthesis---post here immediately.!! I want to post more about what is going on with my setup, but do not want it to fall on deaf ears.


Anyone know what the reduced ammonia/magnetite solution should look like at the 2nd to last step? Should it be liquid or made of soap?




+I have real oleic acid now.

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  • 11 months later...

Hello all!


I'm eager to learn about EM field manipulation and ferro fluids! I've got a science project in mind... I'd like to come up with a way to measure the "RIGIDITY" of ferro fluid under the influence of an EM field. But I'd like to see if it's possible to inject ferro fluid into a balloon, bag, or bladder, filling it with no air pockets... then applying a magnetic field from OUTSIDE the bladder in hopes to manipulate the bladder's shape. I want to measure how rigid the fluid in the bag gets.


Does anyone have any suggestions as to how I can scientifically measure the rigidity? I'd like to come out with some kind of pounds per square inch model.... but I'm not sure how to set up that kind of measurement.


Any suggestions?


My goal is to see if it's possible to create primitive shapes like cubes, globes, and cones out of the baggie filled with ferro fluid. And to see how solid they can become.


Any help on this would be greatly appreciated!

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  • 3 months later...

hey im new, read your post see, lol, well i have synthesised magnetite nanoparticles, if you add brushed iron wool to fecl3 in boiling water give it 15mins and it turns a clear light green, make sure its not steel, sometimes a chromium ferric complex can form a protective oxidative coating, add this in a fecl3:fecl2 2:1 proportion and a source of OH- ions slowly, fe3o4 is only made in an acidic environment, if too much alkali is added at once a high basic environment will form rust(a good way of making thermite), oleic acid can be separated from olive oil by adding a group 1 hydroxide and then mixing an acid with the filtered resulting solid white mass, glycerine dissolves in water, oil floats, decant free fatty acids and its pretty much 80% oleic acid, i was wanting to use kerosene or mineral oil (due to the less offensive smell), a question i ask, what liquid is not soluble in mineral oil that has a lighter specific gravity, adding a lighter liquid allows spikes to form

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  • 8 months later...



Hello all,


Im new to the forums, and I'm trying like many others before me: to synthesize ferrosfluid. I've done quite alot of reading on the web and i have most everything I'll need, I'm trying to make high grade stuff that will produce spikes, similar to this link


At the moment im having trouble getting the magnetite, i plan to try get it by mixing the washing soda and moss killer, i have oleic acid but im not sure how diluted it is. it doesnt seem very viscous.


So I'd like like to make some of that from olive oil. Has anyone had success in any of the area's above?


Also i live in south africa so ordering stuff online is more challenging.

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  • 4 weeks later...

I have recently put in a few of my own attempts at making ferrofluid, and here's some things I learned and my reinterpretation of the guide.




That site goes step by step with words on how to make a ferrofluid including making the magnetite nanoparticles, but after doing it 4 times I found it was a bit vague at alot of parts.


So here is my own step by step guide for making the ferrofluid.



A: Unscented or uncolored ammonia: Got mine from walmart



B: Steel/Iron Wool: Any hardware store, don't get an SOS pad with soap in it



C: PBC Etchant (aka Ferric Chloride Solution: Got mine at Radio Shack



D: Distilled Water: Walmart? Really many places carry this.


E. 2 small class containers in which you can measure out milliliter volumes (I got mine off amazon)



F: 1 larger glass container to mix things in, half to full liter in volume


G. Coffee Filters


H: Something to stir with that isn't metal (I used a wooden doll rod)


I: Rubber Gloves/Saftey Glasses (optional): Better safe than sorry? Can be bought again at most hardware stores.


J: Portable Heat source: Electric stove burner or kerosine camping grill


K: Ice


L: Small plastic tub to put make an ice bath in



1. Set up in a ventilated area (outside) cause this stuff stinks. (alot)


2. Pour 20 milliliters PBC etchant and 20 milliliters distilled water into your glass measuring container.


3. Stuff in a cotton swab sized chunk of steel wool, and using your stirring rod to smash it down in.


4. The steel wool should start dissolving and the solution should start turning a greenish color.


5. Keep adding cottonball size pieces of steel wool and stirring until it stops dissolving. (probably 2-5 pieces depending on how fine the wool is and how tightly balled they are)


6. Pour 20ml PBC etchant into a separate measuring container.


7. Take your solution in which you added steel wool and pour it through a coffee filter into the fresh 20 ml of PBC etchant until it reaches 40 mL. (half straight etchant and half wool-dissolved solution)


8. Pour this new 40 mL of solution into your larger mixing container.


9. Make an ice bath in your plastic tub and chill the solution as well as about 250ml-750ml ammonia(depending on it's concentration) in its own container.

*note cooling the solution and ammonia was recommend to me by the person who made this stuff at his home www.youtube.com/watch?v=PhJms4r1IzU

*I have not yet tried it to see if it makes a difference


10. While stirring slowly(extremely slowly, ideally drop by drop) pour ammonia into this solution. At first it will turn a muddy red-brown and then as you keep adding ammonia it will turn a jet black. Once it goes completely black you have precipitated magnetite.

*This is a long and tedious process


11. Now you have a mixture of water, ammonia, and magnetite. Heat this up to just below boiling for about 15 min.


12. While this is heating (or after it is heated) create a mix of ammonia and oleic acid by heating about 300ml ammonia (mine was weak stuff) and mixing in oleic acid until it starts to form soaps


13. Add this mixture to the magnetite precipitate and stir for a long time to try and fully coat all of the particles present



This last step has a high chance to boil over your container if you heat it too high or rapidly, covering your heater in jet black rust and ammonia that is hard to get off. Err on the side of caution when heating. You have been warned.


And finally after step 13, let the mixture cool and add kerosine and mix. Let the kerosine and water layers separate and suck the top kerosine layer off (this is the ferro fluid.)

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  • 2 months later...



For my ferrofluid recipe, I bought Oleic Acid (Canadawide Scientific), Fe3O4 (eBay), and Kerosene (local hardware store).


Some products are still in transit, so I haven't experimented just yet...


I've done quite a bit of reading on the subject; I understand the fundamentals... But none of the instructions I came across use "already made" Fe3O4 (magnetite?)... and I'm having difficulty deducing where I should pickup on the "recipe". I virtually have no background in chemistry...


To me, the touchy part is effectively bonding the Fe3O4 particles with the Oleic Acid.


Can I coat the Fe3O4 with Oleic Acid by simply mixing them together? Or do I have to heat Amonia, add Oleic Acid, then add the Fe3O4 and continue to heat/mix until the amonia is evaporated? Or... something else?


Then, I guess it's just a matter of cooling the solution (if it was heated in the first place) and adding the Kerosene to get the ideal viscosity. From what I understand, the ratios are roughly - 5% magnetic solids (Fe3O4), 10% surfactant (Oleic Acid), and 85% carrier (Kerosene).


Thank you for your input.

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  • 4 months later...

So, I have successfully made a ferrofluid, but I am just wondering how I should dispose of it short of taking it to a chemical disposal facility. I have access to a typical high school chemical store room. Do I just soak it up with paper towels and throw it out in the trash or down the drain? If not, is there a chemical process I can go through to make it so I can?

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