Homemade Ferrofluid
Part Scavenger, Mon Feb 27 2006, 03:25AMOK, I tried Andrew's ferrofluid tutorial
and I've got some problems. I created the ferrous chloride from the ferric chloride and that part looks right. I was very careful with my measurements, I don't know if that has to do with anything. Here's what happened:After I combined the ferrous choloride and the ferric chloride, I was supposed to add ammonia which was supposed to create magnetite which I was expecting to be black. In my first batch I never saw any black that I can remember, just looked like VERY iron rich water(rusty). Nobody on the net had pics of this stage, so I thought maybe that was normal and as I evaporated the ammonia it would change to black. So, I was supposed to cook it down until the ammonia smell went away, but after the ammonia had all dissolved in the red sludge, there was no smell any more even after heating. I have since learned that this red sludge is ferric hydroxide?
Starting over again, I was able to create black(magnetite?) by adding the ammonia to the ferrous/ferric chloride solution, but it turned red as soon as I saw a little trace of it. This is not what is supposed to happen right?
It might be important to note that I am using olive oil instead of oleic acid, but that doesn't seem to be the problem. I was able to finally work some ferrofluid out of the "ruined" batches by adding ammonia after the mixture was covered in kerosene( the carrier) and then boiling it(which was not recommended). I also now had the ammonia smell and I boiled it until it was gone. This resulted in ferrofluid that works, but no spikes and it gets clumpy, but it does slide around and follow a magnet. I think this (clumping) is because my particles are too big and I think that's because I didn't succeed with the initial precipitation. But, the olive oil in place of the oleic acid seemed to work fine.
Thanks
-Part Scavenger
Re: Homemade Ferrofluid
Michael W., Mon Feb 27 2006, 04:07AM
I made it at school with exact molar solutions and it took two tries to get it to work and even then it wasn't very spectacular....
Michael W., Mon Feb 27 2006, 04:07AM
I made it at school with exact molar solutions and it took two tries to get it to work and even then it wasn't very spectacular....
Re: Homemade Ferrofluid
Part Scavenger, Mon Feb 27 2006, 04:27AM
Although any input would be greatly appreciated, I think I found the answer to the "red" problem. It seems that you need to add the ammonia over a period of several minutes, stirring, and this yields and initial "red" solution that is eventually overcome by the magnetite precipitate. I'll try that Tues if I've got time. I just slowly poured it in there while stirring. I finally found a pic, their precipitate looked really nice, black and orderly. Their product looked quite a bit better than mine too due to small particles. Maybe this will give me what I want...
Part Scavenger, Mon Feb 27 2006, 04:27AM
Although any input would be greatly appreciated, I think I found the answer to the "red" problem. It seems that you need to add the ammonia over a period of several minutes, stirring, and this yields and initial "red" solution that is eventually overcome by the magnetite precipitate. I'll try that Tues if I've got time. I just slowly poured it in there while stirring. I finally found a pic, their precipitate looked really nice, black and orderly. Their product looked quite a bit better than mine too due to small particles. Maybe this will give me what I want...
Re: Homemade Ferrofluid
Nik, Mon Feb 27 2006, 05:34AM
My girlfriend has been attempting ferrofluid for a few days now and has been getting better and better results. I will talk to her tomorro and find out if she has any tips on making it work.
Nik, Mon Feb 27 2006, 05:34AM
My girlfriend has been attempting ferrofluid for a few days now and has been getting better and better results. I will talk to her tomorro and find out if she has any tips on making it work.
Re: Homemade Ferrofluid
Part Scavenger, Mon Feb 27 2006, 03:57PM
That'd be great! Wow, a girl who actually knows what ferrofluid is. Lucky!
Part Scavenger, Mon Feb 27 2006, 03:57PM
That'd be great! Wow, a girl who actually knows what ferrofluid is. Lucky!
Re: Homemade Ferrofluid
Bored Chemist, Mon Feb 27 2006, 06:19PM
Olive oil really isn't the same as oleic acid. It may work, but I somehow doubt it.
Bored Chemist, Mon Feb 27 2006, 06:19PM
Olive oil really isn't the same as oleic acid. It may work, but I somehow doubt it.
Re: Homemade Ferrofluid
Part Scavenger, Mon Feb 27 2006, 06:56PM
I know. It's 83% oleic acid according to my friend who is a chem teacher and a pharmacist I talked to. She said to go ahead and try it. I don't think that's the problem (at least not yet). The the crappy ferrofluid I got after I added ammonia to the "finished" batch and boiled was attached just fine to the kerosene. I made one batch without the oil to see if it was interfering with the ammonia thing, and the kerosene behaved completely differenty(It just floated on top). Duh, I know, but I was testing something and just went ahead and poured in the kerosene to see what would happen.
Part Scavenger, Mon Feb 27 2006, 06:56PM
I know. It's 83% oleic acid according to my friend who is a chem teacher and a pharmacist I talked to. She said to go ahead and try it. I don't think that's the problem (at least not yet). The the crappy ferrofluid I got after I added ammonia to the "finished" batch and boiled was attached just fine to the kerosene. I made one batch without the oil to see if it was interfering with the ammonia thing, and the kerosene behaved completely differenty(It just floated on top). Duh, I know, but I was testing something and just went ahead and poured in the kerosene to see what would happen.
Re: Homemade Ferrofluid
robert, Mon Feb 27 2006, 07:58PM
Not quite, ist a glycerin ester of oleic acid (and others).
The fact that ist a ester and not the free acid makes a huge difference.
robert, Mon Feb 27 2006, 07:58PM
Not quite, ist a glycerin ester of oleic acid (and others).
The fact that ist a ester and not the free acid makes a huge difference.
Re: Homemade Ferrofluid
Part Scavenger, Tue Feb 28 2006, 01:57AM
Huh. Didn't know that. Can I get the oleic out? I'm having trouble finding it in my area. BTW I'd prefer not to do it this way: (They said it's from the middle ages or something)
"To procure oleic acid, treat oil of bitter almonds with caustic potash, and to the soap formed add hydrochloric acid; this separates the oleic and other acids. To the decomposed mixture add about half its weight of oxide of lead, and digest for 2 or 3 hours, at a temperature of 100° C. (212° F.), by which means oleates of the fatty acids are formed. Ether is now added, which dissolves only the oleate of lead; the ethereal solution is mixed with an equal volume of water, to which hydrochloric acid is added as long as is required for decomposition, and the mixture is then well shaken. The ether rises to the surface, holding the oleic acid in solution; decant it and distill it off; there remains a compound of pure oleic acid with oxidized acid. By subjecting this compound to a temperature of about -7.2° C. (19° F.), the pure crystals of oleic acid form, while the oxidized acid remains in solution. "
EDIT+> Are you getting the idea I don't know much about chemistry? Learning more about the oleic acid in olive oil... Only 1% of extra virgin olive oil is free oleic acid, oleic acid still makes up 83% of olive oil, but like robert said, it's the ester and it's tied up in there somehow. Rancid olive oil is up to 24% free oleic acid. Oleic acid can be made from olive oil supposedly easily, but I've yet to find the answer on the internet. Everybody just seems to know how to do it. This much I know: something about HCl, mix it in making sure the solution is acidic, add kerosene? Something about purifying the mixture with the crap you just poured off and something about carboxylic acids. I guess, I don't know, it's kind of put together at this moment. I know it can't be hard to make, people have been making soap with it since dirt apparently. But I can't stand to buy it it's kinda expensive for the 5mL I need. Maybe I need to talk to Granny Clampett...
Another Edit+> Over at the chem fourms, someone suggested filtering the finished ferrofluid with filter paper. According to him, he's made "spikey" ferro-fluid at home and this is the only way to make it work. He says "any magnetite that doesn't have a death grip on the oleic acid is gonna make your ferrofluid clump and cause a mess in your container" Something to that effect.
Part Scavenger, Tue Feb 28 2006, 01:57AM
Huh. Didn't know that. Can I get the oleic out? I'm having trouble finding it in my area. BTW I'd prefer not to do it this way: (They said it's from the middle ages or something)
"To procure oleic acid, treat oil of bitter almonds with caustic potash, and to the soap formed add hydrochloric acid; this separates the oleic and other acids. To the decomposed mixture add about half its weight of oxide of lead, and digest for 2 or 3 hours, at a temperature of 100° C. (212° F.), by which means oleates of the fatty acids are formed. Ether is now added, which dissolves only the oleate of lead; the ethereal solution is mixed with an equal volume of water, to which hydrochloric acid is added as long as is required for decomposition, and the mixture is then well shaken. The ether rises to the surface, holding the oleic acid in solution; decant it and distill it off; there remains a compound of pure oleic acid with oxidized acid. By subjecting this compound to a temperature of about -7.2° C. (19° F.), the pure crystals of oleic acid form, while the oxidized acid remains in solution. "
EDIT+> Are you getting the idea I don't know much about chemistry? Learning more about the oleic acid in olive oil... Only 1% of extra virgin olive oil is free oleic acid, oleic acid still makes up 83% of olive oil, but like robert said, it's the ester and it's tied up in there somehow. Rancid olive oil is up to 24% free oleic acid. Oleic acid can be made from olive oil supposedly easily, but I've yet to find the answer on the internet. Everybody just seems to know how to do it. This much I know: something about HCl, mix it in making sure the solution is acidic, add kerosene? Something about purifying the mixture with the crap you just poured off and something about carboxylic acids. I guess, I don't know, it's kind of put together at this moment. I know it can't be hard to make, people have been making soap with it since dirt apparently. But I can't stand to buy it it's kinda expensive for the 5mL I need. Maybe I need to talk to Granny Clampett...
Another Edit+> Over at the chem fourms, someone suggested filtering the finished ferrofluid with filter paper. According to him, he's made "spikey" ferro-fluid at home and this is the only way to make it work. He says "any magnetite that doesn't have a death grip on the oleic acid is gonna make your ferrofluid clump and cause a mess in your container" Something to that effect.
Re: Homemade Ferrofluid
Heiders, Tue Feb 28 2006, 03:05AM
I am "the gf who knows what ferrofluid is" and I have managed to purchase some real oleic acid from chemistrystore.com and have far more than I can ever use. If you would like, I can sell you some. However:
I had the same problem, the magnetite didn't react. I ended up getting ferrous chloride crystals from my ever-helpful chemistry teacher. With some math, I made up a 1.5M solution and added it to the ferric in the appropriate amounts (2:1).
I did some more research and found another way to make ferrofluid, but some of the basic reactions are the same. It is a .pdf, and can be found here. (chem.wisc.edu) When I added the ammonia, it turned black, but with stirring disappeared. I ended up added about 100mL extra - VERY slowly - to completely react it all. It turned out really dark, but surprisingly brown and not black, however I ran out of time to finish it that night.
The next day the extra ammonia had separated and was sitting on top. I poured off the ammonia and cooked the remainder, but it all clumped into a blob in the middle surrounded by what looked like water with a yellowish tinge. I dont know whether this was supposed to happen or a result of from overcooking or too much/not enough oleic... Any ideas?
After pouring the "water" off, I added the kerosene, which made about 97% of the clumps break up. This solution was kind of responsive to the magnet, but settled a bit overnight. No spikes yet though!
Good luck with yours.
Heiders, Tue Feb 28 2006, 03:05AM
I am "the gf who knows what ferrofluid is" and I have managed to purchase some real oleic acid from chemistrystore.com and have far more than I can ever use. If you would like, I can sell you some. However:
I had the same problem, the magnetite didn't react. I ended up getting ferrous chloride crystals from my ever-helpful chemistry teacher. With some math, I made up a 1.5M solution and added it to the ferric in the appropriate amounts (2:1).
I did some more research and found another way to make ferrofluid, but some of the basic reactions are the same. It is a .pdf, and can be found here. (chem.wisc.edu) When I added the ammonia, it turned black, but with stirring disappeared. I ended up added about 100mL extra - VERY slowly - to completely react it all. It turned out really dark, but surprisingly brown and not black, however I ran out of time to finish it that night.
The next day the extra ammonia had separated and was sitting on top. I poured off the ammonia and cooked the remainder, but it all clumped into a blob in the middle surrounded by what looked like water with a yellowish tinge. I dont know whether this was supposed to happen or a result of from overcooking or too much/not enough oleic... Any ideas?
After pouring the "water" off, I added the kerosene, which made about 97% of the clumps break up. This solution was kind of responsive to the magnet, but settled a bit overnight. No spikes yet though!
Good luck with yours.
Re: Homemade Ferrofluid
Part Scavenger, Tue Feb 28 2006, 03:22AM
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...
Part Scavenger, Tue Feb 28 2006, 03:22AM
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...
Re: Homemade Ferrofluid
..., Tue Feb 28 2006, 03:27AM
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!
..., Tue Feb 28 2006, 03:27AM
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!
Re: Homemade Ferrofluid
Heiders, Tue Feb 28 2006, 04:26AM
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.
Heiders, Tue Feb 28 2006, 04:26AM
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.
Re: Homemade Ferrofluid
Mike, Tue Feb 28 2006, 05:59AM
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 ⇌ NH4+ + OH-
It is the name given to an aqueous solution of Ammonia. So you should be able to create your own.
Mike, Tue Feb 28 2006, 05:59AM
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 ⇌ NH4+ + OH-
It is the name given to an aqueous solution of Ammonia. So you should be able to create your own.
Re: Homemade Ferrofluid
Bored Chemist, Tue Feb 28 2006, 06:18PM
"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.
Bored Chemist, Tue Feb 28 2006, 06:18PM
"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.
Re: Homemade Ferrofluid
Part Scavenger, Tue Feb 28 2006, 06:48PM
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 I’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 they’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 doesn’t seem to matter. It has to do with the concentration. Can I just dump it together? The “extra†stuff would be all soluable in water I think, so it should just pour off right? That way I wouldn’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...
Part Scavenger, Tue Feb 28 2006, 06:48PM
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 I’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 they’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 doesn’t seem to matter. It has to do with the concentration. Can I just dump it together? The “extra†stuff would be all soluable in water I think, so it should just pour off right? That way I wouldn’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...
Re: Homemade Ferrofluid
Bored Chemist, Wed Mar 01 2006, 07:52PM
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).
Bored Chemist, Wed Mar 01 2006, 07:52PM
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).
Re: Homemade Ferrofluid
Part Scavenger, Thu Mar 02 2006, 01:33AM
Thank You!!! I really appreciate it! I will try it as soon as I can. I love this forum.
Part Scavenger, Thu Mar 02 2006, 01:33AM
Thank You!!! I really appreciate it! I will try it as soon as I can. I love this forum.
Re: Homemade Ferrofluid
Omicron, Thu Mar 02 2006, 02:10AM
Why not just buy it? Its pretty cheap, and I have made ferrofluid before try using a technical grade oleic acid.
Omicron, Thu Mar 02 2006, 02:10AM
Why not just buy it? Its pretty cheap, and I have made ferrofluid before try using a technical grade oleic acid.
Re: Homemade Ferrofluid
Heiders, Thu Mar 02 2006, 04:01AM
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...
Heiders, Thu Mar 02 2006, 04:01AM
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...
Re: Homemade Ferrofluid
Part Scavenger, Thu Mar 02 2006, 04:10AM
Mine's clear. That's all I've ever seen my mom buy.
About the filter paper, I wonder what that guy was using. I had similar problems (although I didn't have any "filter paper") but he says it "flowed right through." I hope to try all this stuff out on friday. I will by Sunday or it's gonna kill me.
Part Scavenger, Thu Mar 02 2006, 04:10AM
Mine's clear. That's all I've ever seen my mom buy.
About the filter paper, I wonder what that guy was using. I had similar problems (although I didn't have any "filter paper") but he says it "flowed right through." I hope to try all this stuff out on friday. I will by Sunday or it's gonna kill me.
Re: Homemade Ferrofluid
Omicron, Fri Mar 03 2006, 02:05AM
$40 CND that’s about $50 USD and for a gal that’s cheap, United Nuclear wants $15 for 30 ml. Where did you get yours? What was the quality like?
Omicron, Fri Mar 03 2006, 02:05AM
$40 CND that’s about $50 USD and for a gal that’s cheap, United Nuclear wants $15 for 30 ml. Where did you get yours? What was the quality like?
Re: Homemade Ferrofluid
Michael W., Fri Mar 03 2006, 02:40AM
I do believe there talking about oleic acid, not ferrofluid....
Michael W., Fri Mar 03 2006, 02:40AM
I do believe there talking about oleic acid, not ferrofluid....
Re: Homemade Ferrofluid
Chris, Fri Mar 03 2006, 08:28PM
Has anyone tried forming magnetite from the FeCl2/FeCl3 solution with sodium hydroxide? It should work with any base, and a faster reaction with stronger solution should yield smaller (better) particles. The ammonia is not important until it comes time to coat the magnetite with oleic acid, so forming the magnetite first with sodium hydroxide and then adding ammonia should be a far better method.
Chris, Fri Mar 03 2006, 08:28PM
Has anyone tried forming magnetite from the FeCl2/FeCl3 solution with sodium hydroxide? It should work with any base, and a faster reaction with stronger solution should yield smaller (better) particles. The ammonia is not important until it comes time to coat the magnetite with oleic acid, so forming the magnetite first with sodium hydroxide and then adding ammonia should be a far better method.
Re: Homemade Ferrofluid
Part Scavenger, Sun Mar 05 2006, 01:55AM
Cool. I'll try that. I didn't get a chance to work on anything today or yesterday. But Sunday I have time. Yeah! I'll see what that does. I have noticed that the olive oil/HCL combo I left sitting on my desk the last several days has changed. The "big yellow layer" has almost completely turned into the "little layer above the yellow" I guess this is what Bored Chemist meant by "It would take forever." My chem friend also pointed out that too much HCl could mess up the resulting oleic acid if done this way, so I'll just pitch the stuff sitting on my desk and go for BC's method.
Part Scavenger, Sun Mar 05 2006, 01:55AM
Cool. I'll try that. I didn't get a chance to work on anything today or yesterday. But Sunday I have time. Yeah! I'll see what that does. I have noticed that the olive oil/HCL combo I left sitting on my desk the last several days has changed. The "big yellow layer" has almost completely turned into the "little layer above the yellow" I guess this is what Bored Chemist meant by "It would take forever." My chem friend also pointed out that too much HCl could mess up the resulting oleic acid if done this way, so I'll just pitch the stuff sitting on my desk and go for BC's method.
Re: Homemade Ferrofluid
Carbon_Rod, Sun Mar 05 2006, 03:05AM
Suspension of material in water needs a surfactant no matter what:
2FeCl3 + FeCl2 + 8NH3 + 4H2O -> Fe3O4 + 8NH4CL
Oleic acid C17H33COOH is somewhat easily confused with linoleic acid C17H31COOH. However, tetramethylammonium hydroxide N(CH3)4OH is known to work well as a surfactant for this process. IIRC it is pretty toxic so look at the MSDS.
Have fun,
Carbon_Rod, Sun Mar 05 2006, 03:05AM
Suspension of material in water needs a surfactant no matter what:
2FeCl3 + FeCl2 + 8NH3 + 4H2O -> Fe3O4 + 8NH4CL
Oleic acid C17H33COOH is somewhat easily confused with linoleic acid C17H31COOH. However, tetramethylammonium hydroxide N(CH3)4OH is known to work well as a surfactant for this process. IIRC it is pretty toxic so look at the MSDS.
Have fun,
Re: Homemade Ferrofluid
Chris, Sun Mar 05 2006, 03:54AM
What do you mean here? That reaction doesn't have anything to do with the surfactant, which is oleic acid.
Anyway, the Fe3O4 can be added from any source to the surfactant, which uses ammonia to break it down and bond it to the magnetite. I quote from Andrew's website:
I simply propose the magnetite be formed first using this reaction below, since no one seems to be able to get the reaction above to work at all, and they get poor results when it does (probably because a fast reaction will form smaller particles before larger crystals can form, which is necessary to get spiking, and household ammonia is only 5%-10% NH4OH, plus other additives).
2FeCl3 + FeCl2 + 8NaOH => Fe3O4 + 8NaCl + 4H2O
Once the magnetite is formed here, ammonia and oleic acid would be added in to coat the particles as described above.
It's a rather common idea that "homemade ferrofluid will not spike" or "homemade ferrofluid is not as good as 'real' ferrofluid" but is there some real reason for this? If people who have been attempting to make it at home are getting poor results, obviously we have been doing it wrong. Surely there is nothing magical about making "real" ferrofluid and it's a process that can be replicated. Trying to get the magnetite to precipitate out quickly and uniformly with a small particle size is the first step in trying to produce a quality fluid - commercial ferrofluids are actually available with a variety of particle sizes, where all the home attempts so far seem to have trouble even getting particles to precipitate, much less out of a clear solution.
It might we worth looking into other carrier solvents as well, with different viscosities and surface tension than kerosene. Also has anyone started with anhydrous or a better grade of FeCl3? The PCB etchant you buy could contain additives that interfere. Steel wool is a rather dirty source of iron for the FeCl2 as well, how about washed scrap iron turnings (yes probably a little slow to react) or pure iron powder?
I think I will try the NaOH magnetite sythesis when I go home next weekend for spring break if no one else has tried it by then, just to see how well it works (but I won't be able to get any farther than that because I don't have any oleic acid now
).
Chris, Sun Mar 05 2006, 03:54AM
Suspension of material in water needs a surfactant no matter what:
2FeCl3 + FeCl2 + 8NH3 + 4H2O -> Fe3O4 + 8NH4CL
What do you mean here? That reaction doesn't have anything to do with the surfactant, which is oleic acid.
Anyway, the Fe3O4 can be added from any source to the surfactant, which uses ammonia to break it down and bond it to the magnetite. I quote from Andrew's website:
THE OLEIC ACID REACTS WITH THE AMMONIA TO FORM AMMONIUM OLEATE, A SLIGHTLY SOLUBLE SOAP. THE HEAT CAUSES THE AMMONIUM OLEATE TO BREAK DOWN, AND THE OLEATE ION ENTERS SOLUTION WHILE THE AMMONIA ESCAPES AS A GAS. THE OLEATE ION ATTACHES TO A MAGNETITE PARTICLE, AND IS RECONVERTED TO OLEIC ACID.
I simply propose the magnetite be formed first using this reaction below, since no one seems to be able to get the reaction above to work at all, and they get poor results when it does (probably because a fast reaction will form smaller particles before larger crystals can form, which is necessary to get spiking, and household ammonia is only 5%-10% NH4OH, plus other additives).
2FeCl3 + FeCl2 + 8NaOH => Fe3O4 + 8NaCl + 4H2O
Once the magnetite is formed here, ammonia and oleic acid would be added in to coat the particles as described above.
It's a rather common idea that "homemade ferrofluid will not spike" or "homemade ferrofluid is not as good as 'real' ferrofluid" but is there some real reason for this? If people who have been attempting to make it at home are getting poor results, obviously we have been doing it wrong. Surely there is nothing magical about making "real" ferrofluid and it's a process that can be replicated. Trying to get the magnetite to precipitate out quickly and uniformly with a small particle size is the first step in trying to produce a quality fluid - commercial ferrofluids are actually available with a variety of particle sizes, where all the home attempts so far seem to have trouble even getting particles to precipitate, much less out of a clear solution.
It might we worth looking into other carrier solvents as well, with different viscosities and surface tension than kerosene. Also has anyone started with anhydrous or a better grade of FeCl3? The PCB etchant you buy could contain additives that interfere. Steel wool is a rather dirty source of iron for the FeCl2 as well, how about washed scrap iron turnings (yes probably a little slow to react) or pure iron powder?
I think I will try the NaOH magnetite sythesis when I go home next weekend for spring break if no one else has tried it by then, just to see how well it works (but I won't be able to get any farther than that because I don't have any oleic acid now
).Re: Homemade Ferrofluid
Part Scavenger, Sun Mar 05 2006, 06:06PM
Here's another useful link I found:
Part Scavenger, Sun Mar 05 2006, 06:06PM
Here's another useful link I found:
Re: Homemade Ferrofluid
Chris, Sun Mar 05 2006, 06:36PM
Cool.
That's an aqueous based ferrofluid rather than a non-polar solvent, but the idea remains similar. Look at it spike beautifully too! Again the Fe3O4 synthesis itself should work with about any hydroxide, but I see an acidic solution must be what everyone has been missing, and why iron hydroxide was formed. But, umm, what keeps a side reaction between ammonia and HCl from occurring? They can react to form NH4Cl if it doesn't react with the iron chlorides first.
Chris, Sun Mar 05 2006, 06:36PM
Cool.
That's an aqueous based ferrofluid rather than a non-polar solvent, but the idea remains similar. Look at it spike beautifully too! Again the Fe3O4 synthesis itself should work with about any hydroxide, but I see an acidic solution must be what everyone has been missing, and why iron hydroxide was formed. But, umm, what keeps a side reaction between ammonia and HCl from occurring? They can react to form NH4Cl if it doesn't react with the iron chlorides first.Re: Homemade Ferrofluid
Carbon_Rod, Mon Mar 06 2006, 01:14AM
Chris, I think you know what I meant. ;op
Here is some low yield crud holding a magnet showing creep. I would say about 2/3 of the probable yield was lost because it was made a little differently.
Carbon_Rod, Mon Mar 06 2006, 01:14AM
Chris, I think you know what I meant. ;op
Here is some low yield crud holding a magnet showing creep. I would say about 2/3 of the probable yield was lost because it was made a little differently.
Re: Homemade Ferrofluid
Heiders, Tue Mar 07 2006, 05:15AM
SUCCESS!!!! I have spikes and everything!
Granted, they are small, but I'm excited. They are anywhere from 1-6mm, roughly. Depends on which magnet and how far away it is, as well as how much magnetite has been dragged up the side.
I have made 4 batches of ferrofluid. The first two were unfettered disasters. The third one gave me a blob, but it was black, so I took it as a good sign and moved on to changing the recipe, now having a "feel" for how it worked.
The fourth trial was the one that was split into two batches. They were recombined after showing no good results and filtered. I got a blackish sludge with a silt-like appearance (haven't touched it yet) in my filter paper. This responds to the magnet, whereas the filtered liquid doesn't appear to repond almost at all! Unless I was supposed to keep the stuff in the papers, which doesnt make sense... (It's in a jar anyway)
When my brother came home from university tonight (his hands in photos), he wanted to see my progress, so I brought up trials 3&4. After a little playing around, we noticed small bumps on the wall of jar #3. Long story short, having the magnet against the glass is TOO close, and pulls the particles too strongly. Having it on different angles (it's a ring magnet) and varying distances helped form what you see below.
However: Only the bottom "sludge" is really attracted, and when shaken, the fluid doesnt give spikes! It's too thin. I need to settle out the good particles without losing too much of the bottom stuff. I considered letting it settle, then putting a ring magnet underneath and sucking off the top, but before I do that (and lose a LOT of magnetite suspended in that) I want to pour the whole lot out really thin, like in a glass baking dish.
All the demos on the internet that I have seen used a very thin flat layer, and that was how mine responded, in a thin layer on the side. I have already appropriated my mom's pyrex measuring cup, but she WILL NOT give me a baking dish. So I'm off to Value Village again for a glass dish. More updates after I get there, not too sure when!
Heiders, Tue Mar 07 2006, 05:15AM
SUCCESS!!!! I have spikes and everything!
Granted, they are small, but I'm excited. They are anywhere from 1-6mm, roughly. Depends on which magnet and how far away it is, as well as how much magnetite has been dragged up the side.
I have made 4 batches of ferrofluid. The first two were unfettered disasters. The third one gave me a blob, but it was black, so I took it as a good sign and moved on to changing the recipe, now having a "feel" for how it worked.
The fourth trial was the one that was split into two batches. They were recombined after showing no good results and filtered. I got a blackish sludge with a silt-like appearance (haven't touched it yet) in my filter paper. This responds to the magnet, whereas the filtered liquid doesn't appear to repond almost at all! Unless I was supposed to keep the stuff in the papers, which doesnt make sense... (It's in a jar anyway)
When my brother came home from university tonight (his hands in photos), he wanted to see my progress, so I brought up trials 3&4. After a little playing around, we noticed small bumps on the wall of jar #3. Long story short, having the magnet against the glass is TOO close, and pulls the particles too strongly. Having it on different angles (it's a ring magnet) and varying distances helped form what you see below.
However: Only the bottom "sludge" is really attracted, and when shaken, the fluid doesnt give spikes! It's too thin. I need to settle out the good particles without losing too much of the bottom stuff. I considered letting it settle, then putting a ring magnet underneath and sucking off the top, but before I do that (and lose a LOT of magnetite suspended in that) I want to pour the whole lot out really thin, like in a glass baking dish.
All the demos on the internet that I have seen used a very thin flat layer, and that was how mine responded, in a thin layer on the side. I have already appropriated my mom's pyrex measuring cup, but she WILL NOT give me a baking dish. So I'm off to Value Village again for a glass dish. More updates after I get there, not too sure when!
Re: Homemade Ferrofluid
Chris, Tue Mar 07 2006, 05:19AM
Yay! That's a bit more like it. What methods did you use?
For all the nay-sayers out there who claim that "homemade ferrofluid doesn't spike"... hah
Chris, Tue Mar 07 2006, 05:19AM
Yay! That's a bit more like it.
What methods did you use? For all the nay-sayers out there who claim that "homemade ferrofluid doesn't spike"... hah
Re: Homemade Ferrofluid
Part Scavenger, Tue Mar 07 2006, 01:58PM
Way to go Heidi! I can't wait to get back to trying. I haven't had 5 min since last Tues. Are you still using the lemony fresh ammonia?
How do you think you made batch 3? Do you think letting it sit had anything to do with it?
Part Scavenger, Tue Mar 07 2006, 01:58PM
Way to go Heidi! I can't wait to get back to trying. I haven't had 5 min since last Tues. Are you still using the lemony fresh ammonia?
How do you think you made batch 3? Do you think letting it sit had anything to do with it?
Re: Homemade Ferrofluid
Heiders, Thu Mar 09 2006, 04:19AM
Unsuprisingly, Andrew's formula is quite good. Clearly he tried it several times with success. It is that formula that I used for batch 3 : the difference between working and not working is the things like how long to cook it and what it's supposed to look like when you're done each step.
When I cooked it, I originally thought I had overcooked it, because it clumped into a big, fairly stiff blob in the water leftover.
The next batch I only cooked until it looked like it was ABOUT to clump (starting to make small chunks) and took it off the heat. Anyone else get this clumping deal? It did only take ~15-20 min to cook to this point, and I was cold and it wasn't changing anymore, and I couldn't smell anything because I was sick, so I brought it back inside and poured off the water. This batch didn't work, so I think it's worse to undercook than overcook.
Yes, I think letting it sit probably had something to do with it, I don't know how long is optimal. I thought even the best ferrofluid eventually separates (to some extent) so letting it sit for too long will probably be worse. We can only try at regular intervals to see what the best timing is!
I will do another batch in the next couple days because my internet is currently down and I have lots of free time. I'm posting from a borrowed dialup laptop. Yes, I am still using lemony ammonia. I dont think It should make too much of a difference, Andrew stated "household ammonia" and I'm really starting to trust him on this
See you all in 3-5 days, when my internet comes back.
Heiders, Thu Mar 09 2006, 04:19AM
Unsuprisingly, Andrew's formula is quite good. Clearly he tried it several times with success. It is that formula that I used for batch 3 : the difference between working and not working is the things like how long to cook it and what it's supposed to look like when you're done each step.
When I cooked it, I originally thought I had overcooked it, because it clumped into a big, fairly stiff blob in the water leftover.
The next batch I only cooked until it looked like it was ABOUT to clump (starting to make small chunks) and took it off the heat. Anyone else get this clumping deal? It did only take ~15-20 min to cook to this point, and I was cold and it wasn't changing anymore, and I couldn't smell anything because I was sick, so I brought it back inside and poured off the water. This batch didn't work, so I think it's worse to undercook than overcook.
Yes, I think letting it sit probably had something to do with it, I don't know how long is optimal. I thought even the best ferrofluid eventually separates (to some extent) so letting it sit for too long will probably be worse. We can only try at regular intervals to see what the best timing is!
I will do another batch in the next couple days because my internet is currently down and I have lots of free time. I'm posting from a borrowed dialup laptop. Yes, I am still using lemony ammonia. I dont think It should make too much of a difference, Andrew stated "household ammonia" and I'm really starting to trust him on this
See you all in 3-5 days, when my internet comes back.
Re: Homemade Ferrofluid
..., Wed Mar 15 2006, 05:54AM
well it has been 6 days now...
Any of you guys made more progress? So far Heiders 6mm spikes are the thing to beat...
..., Wed Mar 15 2006, 05:54AM
well it has been 6 days now...
Any of you guys made more progress? So far Heiders 6mm spikes are the thing to beat...
Re: Homemade Ferrofluid
Part Scavenger, Wed Mar 15 2006, 03:14PM
No, I haven't had 1 1/2 hrs continous in two and a half weeks. Then I go out of town tomorrow.
I've been dying to try another batch, but I'll have to wait two weeks I guess. How about you Heidi?
Part Scavenger, Wed Mar 15 2006, 03:14PM
No, I haven't had 1 1/2 hrs continous in two and a half weeks. Then I go out of town tomorrow.
I've been dying to try another batch, but I'll have to wait two weeks I guess. How about you Heidi?Re: Homemade Ferrofluid
Heiders, Fri Mar 17 2006, 10:17PM
*cheers* Yay, now I'm not double posting!
I poured out my batch #3 into my mom's glass pie plate, dragged a magnet around on the bottom to pick up all the magnetite, and poured off the excess liquid. This is the really magnetic stuff, but it dries out really fast. So I took advantage of that by setting up a magnet under the plate and leaving it overnight. Next day, remove magnet and dried spikes stay! Picture below.
Anyway. I have really only had to make one change to the recipe. I think it has to do with the concentration of my ammonia, because anything less than about 250mL (total) will not react out all the magnetite. From another test I ran, I found that if the solution is not completely black BEFORE cooking, it will NOT work. Also: adding ammonia after cooking with oleic will not react all the remaining FeCl3/2 solution. Picture below is about 24h after excess ammonia was added, enough to fully react the solution. (though it separates in about 2h)
I am wondering if I should be adding more oleic or not. It seems logical, the ammonia and oleic are in a 30:1 ratio in the recipe, but if it's just the concentration of my ammonia that is too low, does it need more oleic? Will it just react as the excess reactant or will it hang around and change the properties of the end susbstance? hmmmm!
Happy St. Patrick's Day!
Heiders, Fri Mar 17 2006, 10:17PM
*cheers* Yay, now I'm not double posting!
I poured out my batch #3 into my mom's glass pie plate, dragged a magnet around on the bottom to pick up all the magnetite, and poured off the excess liquid. This is the really magnetic stuff, but it dries out really fast. So I took advantage of that by setting up a magnet under the plate and leaving it overnight. Next day, remove magnet and dried spikes stay! Picture below.
Anyway. I have really only had to make one change to the recipe. I think it has to do with the concentration of my ammonia, because anything less than about 250mL (total) will not react out all the magnetite. From another test I ran, I found that if the solution is not completely black BEFORE cooking, it will NOT work. Also: adding ammonia after cooking with oleic will not react all the remaining FeCl3/2 solution. Picture below is about 24h after excess ammonia was added, enough to fully react the solution. (though it separates in about 2h)
I am wondering if I should be adding more oleic or not. It seems logical, the ammonia and oleic are in a 30:1 ratio in the recipe, but if it's just the concentration of my ammonia that is too low, does it need more oleic? Will it just react as the excess reactant or will it hang around and change the properties of the end susbstance? hmmmm!
Happy St. Patrick's Day!
Re: Homemade Ferrofluid
Conundrum, Fri Mar 24 2006, 10:30AM
(snipped from "NS" article)
The idea relies on simple high-school physics: move a magnet close to a copper coil and the changing magnetic field experienced by the coil will induce an electric current to flow through it. Cheung placed a magnet in a tube filled with ferrofluid, wrapped a coil around the tube, and stuck a magnet at each end to keep the magnet inside moving. The result is a system that turns random motion into electricity, with almost no loss of energy to friction. The key is the exceptional slipperiness of the ferrofluid coating - around 40 times as slippery as ice.
this is interesting, perhaps someone can try this?
-A
Conundrum, Fri Mar 24 2006, 10:30AM
(snipped from "NS" article)
The idea relies on simple high-school physics: move a magnet close to a copper coil and the changing magnetic field experienced by the coil will induce an electric current to flow through it. Cheung placed a magnet in a tube filled with ferrofluid, wrapped a coil around the tube, and stuck a magnet at each end to keep the magnet inside moving. The result is a system that turns random motion into electricity, with almost no loss of energy to friction. The key is the exceptional slipperiness of the ferrofluid coating - around 40 times as slippery as ice.
this is interesting, perhaps someone can try this?
-A
Re: Homemade Ferrofluid
Nik, Mon Mar 27 2006, 04:01AM
Please keep in mind that talk of free energy and perpeual motion is not permitted on 4hv. I see no reason for the magnet inside to keep moving.
Nik, Mon Mar 27 2006, 04:01AM
Please keep in mind that talk of free energy and perpeual motion is not permitted on 4hv. I see no reason for the magnet inside to keep moving.
Re: Homemade Ferrofluid
ragnar, Mon Mar 27 2006, 05:21AM
Nik. You're not making any sense. Where's the pseudoscience?
No perpetual motion involved - it just happens that the magnet will slow down to a stop after converting almost all of its kinetic energy into stored electrical energy, as opposed to rubbing against and heating up the walls of the container.
Of course, the bigger the 'load' on the inductor, the slower your magnet will go as a result of Lenz' law and magnetic braking.
The experiment Conundrum is describing has the magnet in a flux-friendly almost frictionless carrier, so that even the tiniest random motion can move the magnet.
ragnar, Mon Mar 27 2006, 05:21AM
Nik. You're not making any sense. Where's the pseudoscience?
No perpetual motion involved - it just happens that the magnet will slow down to a stop after converting almost all of its kinetic energy into stored electrical energy, as opposed to rubbing against and heating up the walls of the container.
Of course, the bigger the 'load' on the inductor, the slower your magnet will go as a result of Lenz' law and magnetic braking.
The experiment Conundrum is describing has the magnet in a flux-friendly almost frictionless carrier, so that even the tiniest random motion can move the magnet.
Re: Homemade Ferrofluid
Nik, Mon Mar 27 2006, 07:26AM
"stuck a magnet at each end to keep the magnet inside moving"
"The result is a system that turns random motion into electricity"
Those lines are the ones that strike me as not quite science. If some one has a diagram it might clear things up a bit.
Nik, Mon Mar 27 2006, 07:26AM
"stuck a magnet at each end to keep the magnet inside moving"
"The result is a system that turns random motion into electricity"
Those lines are the ones that strike me as not quite science. If some one has a diagram it might clear things up a bit.
Re: Homemade Ferrofluid
ragnar, Mon Mar 27 2006, 08:18AM
I think the implication is that the magnet at each end of the tube is oriented so its poles are alike to the mobile one in between.
Random motion causes magnet in the middle to start gliding on its little ferrofluid blob to one or other end of the tube. "Boink" - since like poles repel, the magnet is returned in the other direction. Induced currents / Lenz's law / magnetic braking, whichever way you want to say it, charges up the capacitor and also slows down the movement of the magnet. "Boink."
ragnar, Mon Mar 27 2006, 08:18AM
I think the implication is that the magnet at each end of the tube is oriented so its poles are alike to the mobile one in between.
-------- --------- --------- |N......S| ==== |S.......N| ==== |N.......S| -------- --------- ---------
Random motion causes magnet in the middle to start gliding on its little ferrofluid blob to one or other end of the tube. "Boink" - since like poles repel, the magnet is returned in the other direction. Induced currents / Lenz's law / magnetic braking, whichever way you want to say it, charges up the capacitor and also slows down the movement of the magnet. "Boink."
Re: Homemade Ferrofluid
Chris, Mon Mar 27 2006, 01:21PM
Wow, and none of that has anything to do with the process of making ferrofluid at home, which is what this thread is about. Let's keep on topic and see if anyone has anything more to add which is productive to this thread.
Chris, Mon Mar 27 2006, 01:21PM
Wow, and none of that has anything to do with the process of making ferrofluid at home, which is what this thread is about. Let's keep on topic and see if anyone has anything more to add which is productive to this thread.
Re: Homemade Ferrofluid
Part Scavenger, Tue Mar 28 2006, 05:13AM
That's great heidi! I'm back from out of town, and I have the rest of the week off (sort of)! Yea! I'll make a batch this week while I'm finishing my DRSSTC. HV and ferrofluid!
Part Scavenger, Tue Mar 28 2006, 05:13AM
That's great heidi! I'm back from out of town, and I have the rest of the week off (sort of)! Yea! I'll make a batch this week while I'm finishing my DRSSTC. HV and ferrofluid!
Re: Homemade Ferrofluid
Part Scavenger, Fri Mar 31 2006, 02:35PM
I tried it again last night. I was able to make a beautiful batch of magnetite, but the oleic acid thing didn't work.
A was afraid at first becuase it was doing that red mud thing again even though I was adding ammonia slowly. So, looking at Heidi's previous post, I thought I might add more. About 80mL's later, the red completely went away and all I had was magnetite which was extremely responsive to a magnet. After evaporating all the ammonia out, which took about 40 min, I added my *oleic acid* It didn't work right at all. I guess I'll just have to get some as I have no way of knowing whether or not I actually got oleic or not. I tried both ways, BC's soapmaking, and the stuff I've had sitting on the counter for a month. Neither seemed to work. 
BTW, why *near boiling*? Why not just boil it?
Part Scavenger, Fri Mar 31 2006, 02:35PM
I tried it again last night. I was able to make a beautiful batch of magnetite, but the oleic acid thing didn't work.
A was afraid at first becuase it was doing that red mud thing again even though I was adding ammonia slowly. So, looking at Heidi's previous post, I thought I might add more. About 80mL's later, the red completely went away and all I had was magnetite which was extremely responsive to a magnet. After evaporating all the ammonia out, which took about 40 min, I added my *oleic acid* It didn't work right at all. I guess I'll just have to get some as I have no way of knowing whether or not I actually got oleic or not. I tried both ways, BC's soapmaking, and the stuff I've had sitting on the counter for a month. Neither seemed to work. BTW, why *near boiling*? Why not just boil it?
Re: Homemade Ferrofluid
Heiders, Fri Mar 31 2006, 02:45PM
Aren't you supposed to add the oleic before or during the first couple minutes of cooking? I have been... What happens (according to Andrew) is the oleic reacts with the ammonia to form ammonium oleate, which breaks down in the heat, the ammonium leaves the solution as a gas and the oleate ion (which you want) is left in solution. Eventually the oleate is reconverted to oleic acid and surrounds the magnetite particles.
It is the oleic that dissolves in the kerosene, not the magnetite. Both are insuluble in water, but oleic is soluble in kerosene, so you have a carrier and a surfactant, respectively.
Mine boiled a couple times when I wasn't looking, it didn't seem to make much difference, but I tried to keep it below boiling as much as I could.
Good to have you back!
Heiders, Fri Mar 31 2006, 02:45PM
Aren't you supposed to add the oleic before or during the first couple minutes of cooking? I have been... What happens (according to Andrew) is the oleic reacts with the ammonia to form ammonium oleate, which breaks down in the heat, the ammonium leaves the solution as a gas and the oleate ion (which you want) is left in solution. Eventually the oleate is reconverted to oleic acid and surrounds the magnetite particles.
It is the oleic that dissolves in the kerosene, not the magnetite. Both are insuluble in water, but oleic is soluble in kerosene, so you have a carrier and a surfactant, respectively.
Mine boiled a couple times when I wasn't looking, it didn't seem to make much difference, but I tried to keep it below boiling as much as I could.
Good to have you back!
Re: Homemade Ferrofluid
Part Scavenger, Sat Apr 01 2006, 01:30AM
Oh.
Man. And I just got all my glassware clean too. I just thought the oleic was supposed to get hot. Not that it had something to do with the ammonia. I'll have more time around sunday, maybe I'll give it another whirl. Thanks for the correction. I'll try adding ammonia to the batch of magnetite I have already and see if that works, if not, I'll make another batch. How's it coming with you?
Part Scavenger, Sat Apr 01 2006, 01:30AM
Oh.
Man. And I just got all my glassware clean too. I just thought the oleic was supposed to get hot. Not that it had something to do with the ammonia. I'll have more time around sunday, maybe I'll give it another whirl. Thanks for the correction. I'll try adding ammonia to the batch of magnetite I have already and see if that works, if not, I'll make another batch. How's it coming with you?Re: Homemade Ferrofluid
Heiders, Sun Apr 02 2006, 04:55PM
Ugh, I am getting so frustrated. No matter how much extra ammonia I add, it won't fully react anymore. I dont know what else to do! I am almost out of ammonia (ie don't have enough for another batch) so I am going to get a different brand and see if that works. Any other ideas?
Heiders, Sun Apr 02 2006, 04:55PM
Ugh, I am getting so frustrated. No matter how much extra ammonia I add, it won't fully react anymore. I dont know what else to do! I am almost out of ammonia (ie don't have enough for another batch) so I am going to get a different brand and see if that works. Any other ideas?
Re: Homemade Ferrofluid
Chris, Sun Apr 02 2006, 06:05PM
You could try mixing up some NaOH solution, probably with similar concentration to the ammonia. I got it to precipitate once with that, but didn't have the supply to continue experimenting.
Chris, Sun Apr 02 2006, 06:05PM
You could try mixing up some NaOH solution, probably with similar concentration to the ammonia. I got it to precipitate once with that, but didn't have the supply to continue experimenting.
Re: Homemade Ferrofluid
Heiders, Thu Apr 06 2006, 04:13AM
Semi-success, I at least can now get the magnetite fully reacted. I used a fresh, filtered (whereas last one was just settled) solution of FeCl2 and new, no scent/colour ammonia. I think having fresh reactants really helped, and I needed far less of the new ammonia than the lemon stuff. Before, I needed ~250mL. Now, I need ~190mL.
When I cooked it however, it didn't fully "blob" the way it did before, so I couldn't pour off the water without losing magnetite. After adding kerosene, I had a thick layer of responsive ferrofluid on top of some water, but it's too thin. I think by leaving it overnight uncovered in a ventilated area, enough kerosene might evaporate to increase the viscosity to a point where spikes can be supported. More on that in a couple days.
There is still a small black blob in the bottom that wont dissolve into the kerosene, not too sure why. Contaminants perhaps?
Any news Part Scavenger?
Heiders, Thu Apr 06 2006, 04:13AM
Semi-success, I at least can now get the magnetite fully reacted. I used a fresh, filtered (whereas last one was just settled) solution of FeCl2 and new, no scent/colour ammonia. I think having fresh reactants really helped, and I needed far less of the new ammonia than the lemon stuff. Before, I needed ~250mL. Now, I need ~190mL.
When I cooked it however, it didn't fully "blob" the way it did before, so I couldn't pour off the water without losing magnetite. After adding kerosene, I had a thick layer of responsive ferrofluid on top of some water, but it's too thin. I think by leaving it overnight uncovered in a ventilated area, enough kerosene might evaporate to increase the viscosity to a point where spikes can be supported. More on that in a couple days.
There is still a small black blob in the bottom that wont dissolve into the kerosene, not too sure why. Contaminants perhaps?
Any news Part Scavenger?
Re: Homemade Ferrofluid
Part Scavenger, Thu Apr 06 2006, 10:44AM
No, no time again, I've had some papers due this week and someother big stuff going on. I don't have a spare hour and a half. I'll try to get back to it soon. I didn't get to try it sunday like I thought.
Part Scavenger, Thu Apr 06 2006, 10:44AM
No, no time again, I've had some papers due this week and someother big stuff going on. I don't have a spare hour and a half.
I'll try to get back to it soon. I didn't get to try it sunday like I thought.Re: Homemade Ferrofluid
cbfull, Fri Apr 07 2006, 12:31PM
Has anyone tried the procedure that uses tetramethylammonium hydroxide as the surfactant? This formulation pops up more frequently than the oleic acid/NH4OH when I do a search on google.
I am planning to test this formulation when I get the chance because I have all the materials. Here is the most descriptive link I could find:
I'm hoping it won't be too hard to make a decent amount of the stuff, I plan to practice with small batches first.
cbfull, Fri Apr 07 2006, 12:31PM
Has anyone tried the procedure that uses tetramethylammonium hydroxide as the surfactant? This formulation pops up more frequently than the oleic acid/NH4OH when I do a search on google.
I am planning to test this formulation when I get the chance because I have all the materials. Here is the most descriptive link I could find:
I'm hoping it won't be too hard to make a decent amount of the stuff, I plan to practice with small batches first.
Re: Homemade Ferrofluid
Heiders, Sun Apr 09 2006, 04:54AM
Ah ha! Thank you for that link, somewhere in it it mentions how susceptible to air oxidation the FeCl2 solution is. That is probably my problem, and having made a fresh solution, things should go well for a week or so. After then, it will most likely oxidize.
I have a wine evacuator, which is a rubber stopper that fits in the top of a wine bottle and has a hand pump to suck out the air. Supposedly makes an opened bottle taste better the day after. Do you think that it would be capable to sucking out enough air to increase the usable life of my solution?
Heiders, Sun Apr 09 2006, 04:54AM
Ah ha! Thank you for that link, somewhere in it it mentions how susceptible to air oxidation the FeCl2 solution is. That is probably my problem, and having made a fresh solution, things should go well for a week or so. After then, it will most likely oxidize.
I have a wine evacuator
, which is a rubber stopper that fits in the top of a wine bottle and has a hand pump to suck out the air. Supposedly makes an opened bottle taste better the day after. Do you think that it would be capable to sucking out enough air to increase the usable life of my solution?Re: Homemade Ferrofluid
Carbon_Rod, Mon Apr 10 2006, 07:36AM
My yield was pretty bad using my own method. However, the nylon stopper on the test tube has worked fairly well for storing the stuff (most of the remaining oxides seem settle out over time.)
Carbon_Rod, Mon Apr 10 2006, 07:36AM
My yield was pretty bad using my own method. However, the nylon stopper on the test tube has worked fairly well for storing the stuff (most of the remaining oxides seem settle out over time.)
Re: Homemade Ferrofluid
Self Defenestrate, Mon Apr 10 2006, 01:43PM
As soon as I get some more ferric chloride I'll give it a shot as well.
Self Defenestrate, Mon Apr 10 2006, 01:43PM
As soon as I get some more ferric chloride I'll give it a shot as well.
Re: Homemade Ferrofluid
GreySoul, Sat Feb 24 2007, 12:41AM
Hi all, first time poster, short term lurker :)
I was refered to you all from Andrew and I think I hit the jackpot for my ferrofluid.
So I made my first 2 batches with about the same success as everyone else here - lumpy blob with no spikes....and then I had success after much experiementing and figured I'd share what I found...
The FeCl3 I use is from Datek and has no adulterants, so the water solution step was bypassed resulting in a more concentrated ferrous chloride, I don't know if that made a huge differnce but it might have. Next up I used a vacum filter and erlynmyer flask to clean up the crud from the steel wool.
After that I was having the same trouble with getting a murky red crud instead of clean magnetite. Adding more ammonia solution certainly helped out. Careful titeration is best because too much ammonia seems to interfere with the oleic acid. At the very least it takes longer to cook it all off. I am using yellow lemon scented ammonia with soaps and surficants added, but not too worried. I noticed the lemon scent, color, and at least some soap comes out in the water.
My first try was with olive oil, and I quickly gave up on that. I got some oleic acid from the chemeistyrystore website as noted above. It was around $40/g delivered. A gallon should make > 100 gallons of ferrofluid, so I'll probably use some to make silly putty as well.
Anyways everything here is great so far, but then I got to the kerosene bit and decided to play around. I added a LOT of kerosene to one batch, about double what Andrew has on his site, and let it sit over night in my garage. The next day I had some very promising results after pouring off the non-magnetic but darkly stained excess kerosene. Tiny spikes form around a fairly weak ring magnet salvaged from a speaker.
But it wasn't spectacular.
So I started to experiment with differnt solvents. I've found that Zippo lighter fluid works the best, but quickly evaporates so your solution has to stay sealed. Goof Off (Xylol and Tolulene I think?) also works well but is considererably more toxic than kerosene or lighter fluid (which smells like kerosene but it works better...)
I tried to suspend the oleic acid in water but no amount of boiling or time seems to make a decent fluid.
Acetone works great to clean up spills, but is a crummy carrier fluid.
Liguid butane also works great for the 30 seonds or so you have before it boils off at STP.
So after all that I've settled on lighter fluid and charcoal starter fluid (same stuff?) as the best carrier for good spikes. Right now I am getting inch long spikes to form in the bottom of a pyrex cooking dish from a weak permanent magnet and when I bring a strong electromagnet near the container I get dancing spikes :)
One other thing I experianced.... I get 3 layers in my cylinder when I do this. A brown solvent layer on top, that shows no magnetism at all, a yellowish brown water layer, and a bottom layer that is the ferro-fluid, yet in the sites I have seen it says the ferrofluid should be the fluid that is suspended in kerosene at the top of the column.... any ideas? it sure makes it easy to get the fluid out since i can just stick a magnet to the bottom of my cylider and pour the rest off, but shouldn't I get some other results?
-Doug
p.s. sorry for raising a dead article, I just noticed the last post date... but hey... I'm new :) I'll post pics when I get some. Maybe tonight?
GreySoul, Sat Feb 24 2007, 12:41AM
Hi all, first time poster, short term lurker :)
I was refered to you all from Andrew and I think I hit the jackpot for my ferrofluid.
So I made my first 2 batches with about the same success as everyone else here - lumpy blob with no spikes....and then I had success after much experiementing and figured I'd share what I found...
The FeCl3 I use is from Datek and has no adulterants, so the water solution step was bypassed resulting in a more concentrated ferrous chloride, I don't know if that made a huge differnce but it might have. Next up I used a vacum filter and erlynmyer flask to clean up the crud from the steel wool.
After that I was having the same trouble with getting a murky red crud instead of clean magnetite. Adding more ammonia solution certainly helped out. Careful titeration is best because too much ammonia seems to interfere with the oleic acid. At the very least it takes longer to cook it all off. I am using yellow lemon scented ammonia with soaps and surficants added, but not too worried. I noticed the lemon scent, color, and at least some soap comes out in the water.
My first try was with olive oil, and I quickly gave up on that. I got some oleic acid from the chemeistyrystore website as noted above. It was around $40/g delivered. A gallon should make > 100 gallons of ferrofluid, so I'll probably use some to make silly putty as well.
Anyways everything here is great so far, but then I got to the kerosene bit and decided to play around. I added a LOT of kerosene to one batch, about double what Andrew has on his site, and let it sit over night in my garage. The next day I had some very promising results after pouring off the non-magnetic but darkly stained excess kerosene. Tiny spikes form around a fairly weak ring magnet salvaged from a speaker.
But it wasn't spectacular.
So I started to experiment with differnt solvents. I've found that Zippo lighter fluid works the best, but quickly evaporates so your solution has to stay sealed. Goof Off (Xylol and Tolulene I think?) also works well but is considererably more toxic than kerosene or lighter fluid (which smells like kerosene but it works better...)
I tried to suspend the oleic acid in water but no amount of boiling or time seems to make a decent fluid.
Acetone works great to clean up spills, but is a crummy carrier fluid.
Liguid butane also works great for the 30 seonds or so you have before it boils off at STP.
So after all that I've settled on lighter fluid and charcoal starter fluid (same stuff?) as the best carrier for good spikes. Right now I am getting inch long spikes to form in the bottom of a pyrex cooking dish from a weak permanent magnet and when I bring a strong electromagnet near the container I get dancing spikes :)
One other thing I experianced.... I get 3 layers in my cylinder when I do this. A brown solvent layer on top, that shows no magnetism at all, a yellowish brown water layer, and a bottom layer that is the ferro-fluid, yet in the sites I have seen it says the ferrofluid should be the fluid that is suspended in kerosene at the top of the column.... any ideas? it sure makes it easy to get the fluid out since i can just stick a magnet to the bottom of my cylider and pour the rest off, but shouldn't I get some other results?
-Doug
p.s. sorry for raising a dead article, I just noticed the last post date... but hey... I'm new :) I'll post pics when I get some. Maybe tonight?
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