I would like to make water-based ferrofluid with MICR toner. The intention of this is to use the magnetic particles to visualize some spaces in biological samples with CT scanning. Because biological samples are stored in water-based solutions, I am hoping that submerging samples in water based ferrofluid in shaker would filling some spaces but do not go through membranes due to nanosized particles of ferrofluid. Also iron should absorb x-ray enough to visualize some filled spaces with ferrofluid with CT. Such water based ferrofluid is sold by company but it is kind of expensive. So I am trying to make water-based ferrofluid with MICR toner.
So far, I have mixed toner (5ml) in water (7.5ml) and sugar (10g = about 20ml) as surfactant. I mixed them in glass vial tube but I see some aggregation of irons along the glass wall and some separation of toner and water that do not show any homogenous solutions. Also the toner is powdery on the upper layer of the solution. Should I change the percentage of those water, sugar and toner? Or is there any better way to make water-based ferrofluid with toner? I think for my purpose I don’t need complete homogenous solution though as long as it is mixed and delimit the membrane.
Alternatively, I could move samples into ethanol series. so i have tried to mix toner and 70% ethanol.
This mixture shows very homogenous solutions but i could see some irons sank in the bottom. Although it does not matter if some of them were sank in the bottom as long as the some iron nanoparticle goes into the spaces. However, again some of them aggregated and showed big particles on the surfaces of the samples that did not seem to enter the spaces (although it is hard to say with eye-ball observations).
I saw several posts about making aqueous ferrofluid that finding a cheap water-soluable ferromagnetic compound and synthesis of aqueous solution from out of FeCl3 and FeCl2. So does that mean that MICR toner is not water-soluable and it is not possible to make water-based ferrofluid with MICR toner?
I appreciate any suggestions!