prevent ferrofluid staining container?

[aliasjanedoe]

So this site

http://www.teachersource.com/ElectricityAndMagnetism/Ferrofluid/FerrofluidPreformDisplayCell.aspx

has ferrofluid in a display tube that doesn't get all stained. How in the world did they do that?? I want to do something like this, but shrunk down into pendant size for a necklace. I thought glass would be less likely to stain than plastic, but nothing works to coat it. Has anybody tried filling a container (lava-lamp style)? Is this just mission impossible? Help!

 

Thanks.

[Alexein]

The trick is actually to cheat.... instead fill the container FULL of another fluid that the ferrofluid is immiscible in but "stains" the container better than the ferrorfluid.

 

If your ferrofluid doesn't dissolve in water, because it has an organic carrier fluid, you could try filling your container with water and ferrofluid and maybe you'll get the effect you want.

 

other solvents might include alcohols, phthalate esters or fluorinated organics.

[aliasjanedoe]

The trick is actually to cheat.... instead fill the container FULL of another fluid that the ferrofluid is immiscible in but "stains" the container better than the ferrorfluid.

 

Hmm, I hadn't thought of that. What would you suggest?

 

And can anybody recommend somewhere to buy ferrofluid that's nice and spiky? If I try making it myself, I'll get a glob monster from the black lagoon instead of a hedgehog.

[hermanntrude]

amazon.com

 

that's the american amazon, but i know the canadian and UK ones also used to sell it... they probably still do.

[aliasjanedoe]

I think I'm going to try isopropyl alcohol and water. Sound likely to work? Opinions? My sister said to try vodka. Anybody happen to have some ferrofluid lying around who could test it? I still haven't ordered mine. Hermanntrude, which specific kind did you get from Amazon? Thanks.

[hermanntrude]

i havent bought any yet. I think they're all fairly similar when you get the commercial ones.

[DarkMatter]

I think I'm going to try isopropyl alcohol and water. Sound likely to work? Opinions? My sister said to try vodka. Anybody happen to have some ferrofluid lying around who could test it? I still haven't ordered mine. Hermanntrude, which specific kind did you get from Amazon? Thanks.

 

Pretreatment of the glass by: 1) soaking it overnight in a strong solution of KOH in ethanol or 2) by coating the inside with Scotchgard® spray and drying will help the ferrofluid drain more rapidly

 

or you could try applying a film forming sealant such as they use on concrete garage floors

 

quoted from " http://www.everythin...oor-sealer.html "

 

FILM FORMING SEALERS: These form a protective film on the surface of the concrete. This thin film blocks water and harmful chemicals from being absorbed into the concrete.

 

Film forming sealers are great for decorative concrete because they will darken and highlight the colors in the concrete. The film or clear skin it leaves on the surface will be slippery when it gets wet. Non skid additives can be used to keep the surface from being too slippery.

 

There are three types of film forming sealers, Acrylics, Polyurethanes, and Epoxies. Acrylics are the easiest and least expansive to use. A good water or solvent based acrylic is all you need for a very good, easy to apply garage floor sealant.

 

Acrylic floor sealers can be applied with a pump up sprayer or paint roller. They usually dry within an hour and come in different sheen levels, if you like a shiny gloss look this is the sealer to get.

 

 

not very scientific i know , but neither was the lightbulb when it began cheers!

 

 

p.s. after treating the container, make sure to fill it with the desired medium first , then add the ferrofluid (add just under the surface tension) no air pockets allowed

i have seen windex used but i am not sure if it would eventualy break down the ferrofluid's "carrier fluid"

Edited June 5, 2011 by DarkMatter

[goutham]

There is is more info over here:

http://www.chemicalforums.com/index.php?topic=86668.0