Solutions ferrofluids

Magnetic nanoparticles in ferrofluids can incorporate chemically active agents in order to fix them or separate them from a solution. Ferrofluids of this type have been designed for environmental applications, catalysis, ion recovery processes, etc. For instance, magnetite polymer poly(l-vinylimidazole) nanocomposites have been used for the selective separation/recovery of metal ions in water. ... 

P 71 ] For fluid transport, ferrofluid magnetic displacement by using a commercial hydrocarbon-based ferrofluid was applied [159], This fluid is compatible with several aqueous dyed solutions. Miniature permanent magnets were used. 

A method for the production of stable iron colloids in solution has been developed." Sonication of Fe(CO)5 in the presence of a polyvinylpyrrolidone (PVP) stabilizer yielded an iron colloid with a particle size ranging from 3 to 8nm, while sonication in oleic acid yielded colloids with a uniform size of 8nm. Heating of the resulting colloids yielded bcc-Fe. The colloids were superparamagnetic, with a saturation magnetization of 101 emug , compared to a saturation magnetization of 123 emu g for a typical iron-based ferrofluid. 

From Figure 1.1, we can see the Co particles prepared by thermal decomposition the raw materials are octacarbonyldicobalt and dichlorobenzene. Twenty years ago, Massart developed a method to synthesize magnetic ferrofluids based on the coprecipitation of Fe salts in aqueous solutions using repulsive electrostatic forces. The image of Fe oxidation product is slightly different from the Co product, as is shown in Figure 1.2. 

In what follows the magnetoviscosity phenomenon is analyzed by formulating the local ferrohydrodynamic model, the upscaled volume-average model in porous media with the closure problem, and solution and discussion of a simplified zero-order steady-state isothermal incompressible axisymmetric model for non-Darcy-Forchheimer flow of a Newtonian ferrofluid in a porous medium of the... 

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