• Nano Magnetic Ferrofluid Synonyms:

nano magnetic ferrofluids, magnetic nano particles, ferrofluid nano, magnetic liquid, liquid containing iron, nano-grade ferrofluid, ferrofluidic substance, colloidal ferromagnetic particles, colloidal magnetite suspension, magnetic ferrofluid,

• Nano Magnetic Ferrofluid Background Information:

a) Ferrofluids are colloidal mixtures composed of nanoscale ferromagnetic, or ferrimagnetic, particles suspended in a carrier fluid, usually an organic solvent or water. The ferromagnetic nano-particles are coated with a surfactant to prevent their agglomeration (due to van der Waals forces and magnetic forces). Although the name may suggest otherwise, ferrofluids do not display ferromagnetism, since they do not retain magnetization in the absence of an externally applied field. In fact, ferrofluids display (bulk-scale) paramagnetism, and are often described as "superparamagnetic" due to their large magnetic susceptibility. Permanently magnetized fluids are difficult to create at present.

b) The difference between ferrofluids and magnetorheological fluids (MR fluids) is the size of the particles. The particles in a ferrofluid primarily consist of nanoparticles which are suspended by Brownian motion and generally will not settle under normal conditions. MR fluid particles primarily consist of micrometre-scale particles which are too heavy for Brownian motion to keep them suspended, and thus will settle over time due to the inherent density difference between the particle and its carrier fluid. These two fluids have very different applications as a result. Source: Wikipedia

• Nano Magnetic Ferrofluid Chemical Family:

Colloidal dispersion

• Nano Magnetic Ferrofluid Description:

a) Ferrofluids are composed of nanoscale particles (diameter usually 10 nanometers or less) of magnetite, hematite or some other compound containing iron. This is small enough for thermal agitation to disperse them evenly within a carrier fluid, and for them to contribute to the overall magnetic response of the fluid. This is analogous to the way that the ions in an aqueous paramagnetic salt solution (such as an aqueous solution of copper(II) sulfate or manganese(II) chloride) make the solution paramagnetic.

b) Ferrofluids are tiny iron particles covered with a liquid coating, also surfactant that are then added to water or oil, which gives them their liquid properties. Ferrofluids are colloidal suspensions - materials with properties of more than one state of matter. In this case, the two states of matter are the solid metal and liquid it is in. This ability to change phases with the application of a magnetic field allows them to be used as seals, lubricants, and may open up further applications in future nanoelectromechanical systems.

c) True ferrofluids are stable. This means that the solid particles do not agglomerate or phase separate even in extremely strong magnetic fields. However, the surfactant tends to break down over time (a few years), and eventually the nano-particles will agglomerate, and they will separate out and no longer contribute to the fluid's magnetic response. The term magnetorheological fluid (MRF) refers to liquids similar to ferrofluids (FF) that solidify in the presence of a magnetic field. Magnetorheological fluids have micrometre scale magnetic particles that are one to three orders of magnitude larger than those of ferrofluids.

d) However, ferrofluids lose their magnetic properties at sufficiently high temperatures, known as the curie temperature. The specific temperature required varies depending on the specific compounds used for the nano-particles.

• Nano Magnetic Ferrofluid Chemical Properties Available:

a) Thermal conductivity of a ferrofluid depends linearly on the solid loading. Fluorocarbon based ferrofluids have the lowest thermal conductivity of all commercial ferrofluids, therefore they are the least desirable materials for heat transfer applications.

b) Ferrofluids are loaded with nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid.

c) In devices, ferrofluids come in contact with a wide variety of materials. It is necessary to ensure that ferrofluids are chemically compatible with these materials. The fluids may be exposed to hostile gases, such as in the semiconductor and laser industries; to liquid sprays in machine tool and aircraft industries; to lubricant vapors in the computer industry; and to various adhesives in the speaker industry. Furthermore, ferrofluids may be in contact with various types of plastics and plating materials. The surface morphology can also affect the behavior of the fluid. The selection of ferrofluid is carefully engineered to meet application requirements.

• Physical Properties Available:

Usually to customer specification 

• Nano Magnetic Ferrofluid For Specific Applications:

Ferrofluids are used in many areas. In medicine, for example, they are used as a contrast medium in x-ray exams or for treating tumors. In aviation, they are added to paint to create a coating that absorbs radar waves and thus renders airplanes invisible to radar.

a) Electronic devices
 
b) Mechanical engineering
 
c) Military
 
d) Aerospace
 
e) Analytical Instrumentation
 
f) Medicine
 
g) Heat transfer

h) Optics
 
i) Art

• Nano Magnetic Ferrofluid Packaging:

Usually to customer specification 

• Nano Magnetic Ferrofluid TSCA (SARA Title III) Status:

Listed. For further information please call the E.P.A. at +1.202.554.1404

• Nano Magnetic Ferrofluid CAS Number:

Varies

• Domains Of Nanoparticles & Clusters With Different Structures:
  

a) Molecules= (~1 to 10 atoms)

b) Clusters= (~10 to 10³ atoms)

c) Particles= (~10³ to 10⁵ atoms) 

d) Bulk= (~10⁵ atoms and larger)   Source: University of Texas at Austin