Ferrofluid Keychains

[Hamspiced]

I’m a fidgeter by nature. I’m always playing around with something while working. Since I had been planning my xg3 for a least a month I knew I had an opportunity to create something I can play with it while it healed and not worry about messing up the healing process.

I immediately started researching ferrofluid.

I was always interested in it but this gave me an excuse to really get into it.

I bought a couple different brands from the usual suspects and started looking at vessels for my new toy and then started looking at different suspension liquids.

This turned into a big process as this stuff really is particular.

I found a set of vials I really liked. Some YouTube videos then mentioned it works great in a 50/50 mixture of IPA and water. So that’s what I went with. Initially yeah it worked great but I noticed the solution turned rather dingy yellow and I had some bad staining on the vials.

So next i read up more and switching to 91% IPA, and distilled water helped on both the staining and the color.

It did but somehow it destroyed the properties of the Ferrofluid that I l Ioved

So I did more research and turns out a super saturated salt water mixture, and a vessel cleaning process is what gives clear liquid with maintaining the properties that I wanted. The downside is the vessels I’m using are tiny. Like they hold 50 microdoses of liquid.

The process essentially is. Put oxyclean and distilled water in the vessel for 2 days until the oxyclean dissolves. Clean vessel, and put a supersaturated nacl mixture in the vessel. Allow vessel to sit for 2 days. Boil your ferrofluid and place immediately into salt water vessel.

The results are great and exactly what I wanted. The process though is painful.

I’m probably going to make a few more of these and throw them on my tindie but I love the way it turned out

[XEMON]

Love the idea

Have you tried to put the iron powder in oil?

[mfries18]

I wonder is something like mineral oil would work

[Hamspiced]

I tried mineral oil, Kerosene, and pure grain alcohol.

So far the salt water method seems to be the best results

[amal]

@Hamspiced

So far the salt water method seems to be the best results

Having absolutely no knowledge of ferrofluid, I’m still going to posit a guess here and say the ferrite molecules / particles are likely suspended in a kind of oil to keep them from oxidizing immediately into iron oxide (rust), which is not paramagnetic and would moot the point completely. You need to use water to ensure the surface tensions of the two fluids don’t easily allow the contents to mix / form a suspension. The salt should add density to the water, slowing down the ferrofluid and giving it the “wave like behavior” we’re used to, and it should also tend to saturate the water so it can’t easily accommodate oil droplets breaking off and forming a suspension of oil in the water.

[Hamspiced]

You’re correct. The two types of fluid I have are suspended in Kerosene and another i think In some mineral oil.

The cleaning process is to stop the molecules from adhering to the microscopic divits in the glass.

The solution needs to be a polar opposite of the ferrite suspension.

The super saturated salt mixture is the surfactant.

The other issue is boiling down the Ferrofluid to make it more concentrated from its suspension.

There’s another mixture using sugar I may try but it’s difficult to get pure sugar with no contaminants. At least with salt I can get kosher salt without any anti caking agents.

[amal]

yay i guessed right!

[DonFire]

Got some more information on the ferrofluid you like the most? From what I recall the past few times I have looked into this sort of thing, there’s only two brands that make really good fluid but it’s rebranded and sold by a few different places.

[Hamspiced]

Yes!!

I have three different types. One from Amazon, one from Aliexpress and one from eBay.

Aliexpress and Amazon came in the exact same plastic bottle with a paper label.

The eBay one came in a glass container.

Both fluids need to be boiled off for about an hour. The plastic containers have significantly more suspension liquid which stains glass almost immediately and colors the suspension liquid you try to use. The glass container seems to have more concentrate Ferrofluid. When boiled off it produces a thick dark Ferrofluid with no staining

Hope that helps

[Hamspiced]

In my testing I found a brilliant way to clean the Ferrofluid prior to adding it into it’s new suspension. The issue with using the fluid directly from the container when you receive it is that Ferrofluid has to be in a suspension liquid of some sort. It’s usually Kerosene or mineral oil from what I’ve seen and read about. The issue is that vastly more suspension than nanoparticles exists within the solution. So if you use it directly you will have; cloudy brown liquid, staining of your transfer vessel, weak fluid reactions to magnets. So to combat the problem you have to clean your fluid prior to transfer.

The current documented way of doing it is transferring it into a vessel and heating it at 100*c for 3 hours until the fluid reduces by 10% weight. This process is to evaporate the suspension it is in and concentrate the fluid. The next step is to extract the fluid from just above the bottom of the vessel.

The way I’ve found that works better. After heating for at least 2 hours. Use a strong magnet and carry the dense Ferrofluid fluid from the bottom to the side of the vessel. Use a syringe into the heart of the Ferrofluid blob and extract your usable fluid from that. Repeat with the magnet and syringe until you have the desired amount of fluid.

This new process severely cuts down on time. Also reduces the chances of completely destroying a good clean vessel if you don’t happen to extract your fluid from just above the bottom of your reduction vessel.

[amal]

I’m not exactly sure but wouldn’t using a strong magnet at the bottom of the container without heat allow you to pull the ferrite particles down to the bottom and then you could just use a syringe to remove some of the liquid? Minimal time and no heat (or minimal heat)?

If you’re evaporating oil from the mixture, it would theoretically create a thin coating all over everything in the vicinity. This happens with oil based vacuum pumps too. It’s nasty. Anything to avoid contamination of the lab is a good thing.

[Hamspiced]

Yes you could… but there’s issues in trying that. One no matter how bright a light I shine I can’t see the oil separation from the ferrite particles, also as they combine in one area they start to reduce it’s effectiveness so you can’t tell within the mixture where your ferrite blob is so you don’t know where to pull from.

When you heatb the mixture the surface tension of the oil drops, and yes it does put a thin layer over the top of the mixture, however I noticed when the reduced surface tension i can see the oil dripping down as I pull the blob.
Then using a syringe to extract from the middle of the blob further helps .

You can see the effect of residual oil transfer in almost any YouTube video with Ferrofluid as it will coat and skim the top of the solution they add it to.