Ferrofluid Nanotechnology - Chemical Demonstration Kit

A magnetic liquid, also known as a ferrofluid, may seem like a space-age concept. That's because it is! Now you can prepare a ferrofluid and demonstrate the concept that was invented by NASA in the 1960s to control liquids in space. The procedure is remarkably simple. Magnetite (Fe3O4) is prepared by combining Fe2+ and Fe3+ ions with a weak base in dilute aqueous solution. The resulting magnetite particles are extremely small nanoparticles. Shrinking the size of solid-phase particles to the nanometer scale—one-billionth of a meter—radically changes their physical and chemical properties. Rather than settle out as a solid, the magnetite particles remain suspended in the aqueous medium, giving rise to a magnetic liquid! Place a magnet under the liquid in a Petri dish or vial, and the liquid will form dramatic spikes. Nanotechnology may well be the next “big thing” in science—pun intended. Update your curriculum today!

Concepts: Ferrimagnetic substances and magnetic properties, colloids vs. solutions, nanotechnology.
Time Required: 10 minutes
Materials Provided: Iron(II) chloride and iron(III) chloride, ammonia solution, tetramethylammonium hydroxide solution, hydrochloric acid solution, neodymium magnet, Pasteur pipets, and weighing dishes.
Note: Perform this demonstration in a fume hood or well-ventilated lab.