Synthesis and properties of different corona structure Fe₃O₄ solvent-free nanofluids

Fe₃O₄ solvent-free nanofluids were prepared, using with N-trimethoxysilylpropyl-N, N, N-trim-ethylammonium chloride as corona and anion C₉H₁₉-C₆H₄ - (OCH₂CH₂)₂₀O (CH₂)₃SO₃^- as canopy. Rheometer properties of different corona structure nanofluids were compared. The product was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrum (FT-IR), thermogravimetric analysis (TGA) and rheometer. As a result, Fe₃O₄ nanoparticles possessed good dispersion, and the content of Fe₃O₄ nanoparticals in the nanofluid proved to be about 10.42%. The loss shear modulus G″ of the product was obviously higher than the storage shear modulus G', this showed that the product which could flow at room temperature had obvious rheological behavior. For the solvent-free nanofluids, the long chain corona has the internal plasticization, which can decrease the loss modulus of system, while the short chain of corona will result in the high viscosity of nanofluids. Long alkyl chains of modifiers lead to lower viscosity and better flowability of nanofluids.