encipher - 16-1-2007 at 12:32
Hi,
I have a vial that contains ferrofluid suspended in a kerosene solution. I want to seal the vial and perhaps give it to a friend of mine to 'play
with'. The problem arises when the vial is moved or shaken, or a magnet is brought close. It becomes coated with the ferrofluid (black) and then
nothing on the inside is visible, it sticks to the inside of the vial, which is glass. Is there any coating I can use to coat the inside of the vial
with such that all the kerosene based ferrofluid will not stick to the sides of the vial?
Thanks.
12AX7 - 16-1-2007 at 13:13
Teflon?
Wait, that doesn't stick to a damned thing.
Ooh, silicone rubber?
encipher - 16-1-2007 at 15:00
It should be a clear coating, otherwise it would beat the whole purpose.
Ozone - 16-1-2007 at 15:28
Hmm.
The surface of non-silanized glass is polar, specifically from the silanol (Si-OH <--> Si-O-) groups. It appears that either your glass is
treated or, more likely, you are seeing a by-product of the fact that nano particles are quite "sticky". I am not sure how to passivate a polar
surface vs. "nano-sticky" effects. I'll poke around a bit and get back to you (I know sonication is frequently employed to keep the particles from
aggregating).
Cheers,
O3
neutrino - 17-1-2007 at 08:10
Soaking glass in a strongly basic solution will make the surface hydrophilic by changing its composition from Si - O - Si to Si - OH. I don't know how
much that would help here, though.