Magnetic Ionic Liquids Produced by the Dispersion of Magnetic Nanoparticles in 1-n-Butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf₂)

Abstract

̀This paper reports on the advancement of magnetic ionic liquids (MILs) as stable dispersions of surface-modified γ-Fe(2)O(3), Fe(3)O(4), and CoFe(2)O(4) magnetic nanoparticles (MNPs) in a hydrophobic ionic liquid, 1-n-butyl 3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf(2)). The MNPs were obtained via coprecipitation and were characterized using powder X-ray diffraction, transmission electron microscopy, Raman spectroscopy and Fourier transform near-infrared (FT-NIR) spectroscopy, and magnetic measurements. The surface-modified MNPs (SM-MNPs) were obtained via the silanization of the MNPs with the aid of 1-butyl-3-[3-(trimethoxysilyl)propyl]imidazolium chloride (BMSPI.Cl). The SM-MNPs were characterized by Raman spectroscopy and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy and by magnetic measurements. The FTIR-ATR spectra of the SM-MNPs exhibited characteristic absorptions of the imidazolium and those of the Fe-O-Si-C moieties, confirming the presence of BMSPI.Cl on the MNP surface. Thermogravimetric analysis (TGA) showed that the SM-MNPs were modified by at least one BMSPI.Cl monolayer. The MILs were characterized using Raman spectroscopy, differential scanning calorimetry (DSC), and magnetic measurements. The Raman and DSC results indicated an interaction between the SM-MNPs and the IL. This interaction promotes the formation of a supramolecular structure close to the MNP surface that mimics the IL structure and is responsible for the stability of the MIL. Magnetic measurements of the MILs indicated no hysteresis. Superparamagnetic behavior and a saturation magnetization of ~22 emu/g could be inferred from the magnetic measurements of a sample containing 50% w/w γ-Fe(2)O(3) SM-MNP/BMI.NTf(2).

An experimental study on the synthesis of poly(vinyl pivalate)-based magnetic nanocomposites through suspension polymerization process

“…This behavior indicates that the OA-modified NPMM were into the monomeric phase during the formation of PPVi. Raman spectroscopy is a powerful tool for the identification of the iron oxide magnetite dispersed into the PPVi polymer matrix [7,[79][80][81]. attention should be given to the wavenumber interval from 760 cm -1 to 625 cm -1 , depicted in Fig.…”

Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications

“…The surface modification of g-Fe 2 O 3 , Fe 3 O 4 , and CoFe 2 O 4 NPs using BMSPI.Cl could produce 30-50 % (w/w) magnetic ionic liquids (MILs) with average size of 9.3, 12.3, and 11.0 nm, respectively, without phase separation at high magnetic fields. [176] Significant changes in the saturation magnetization were observed for surface-modified Fe 3 O 4 NPs owing to enhanced oxidation after heat treatment. Furthermore, the Newtonian fluid behavior of the Fe 2 O 3 MIL con-firmed the formation of a supramolecular IL structure surrounding the MNPs and forming a barrier for particle aggregation.…”

“…Reaction of MNP with 1-n-butyl-3-[3-(trimethoxysilylpropyl)]imidazolium chloride (BMSPI.Cl) to form a surface-modified (SM) MNP. Reproduced with permission from reference [176]. Copyright 2012 American Chemical Society.…”

Colloidal Dispersions of Oxide Nanoparticles in Ionic Liquids: Elucidating the Key Parameters

“…Stable colloids with nanoparticles coated with small organic ligands are reported in trihexyl(tetradecyl)phosphonium bis(2,4,4trimethylpentylphosphinate) 13 and EAN 17,18 . Surfactants having groups that imitate groups of the ionic liquid are used to stabilise nanoparticles in EMIM TFSI 19 , BMIM X (X=TFSI 20 , BF 4 21 ), and C r MIM X (r=6,7,8 and X=TFSI 2 , r=2,4,6 and X=BF 4 22 ).…”