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

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• 作者：Anderson M. M. S. Medeiros ; Alexandre L. Parize ; Vanda M. Oliveira ; Brenno A.D. Neto ; Andris F. Bakuzis ; Marcelo H. Sousa ; Liane M. Rossi ; Joel C. Rubim
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：October 24, 2012
• 年：2012
• 卷：4
• 期：10
• 页码：5458-5465
• 全文大小：405K
• 年卷期：v.4,no.10(October 24, 2012)
• ISSN：1944-8252

文摘

̀This paper reports on the advancement of magnetic ionic liquids (MILs) as stable dispersions of surface-modified 纬-Fe₂O₃, Fe₃O₄, and CoFe₂O₄ magnetic nanoparticles (MNPs) in a hydrophobic ionic liquid, 1-n-butyl 3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf₂). 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鈥揳ttenuated 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鈥揙鈥揝i鈥揅 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 纬-Fe₂O₃ SM-MNP/BMI.NTf₂.

Keywords:

ref="http://pubs.acs.org/action/doSearch?action=search&searchText=magnetic+ionic+liquid&qsSearchArea=searchText">magnetic ionic liquid; ref="http://pubs.acs.org/action/doSearch?action=search&searchText=ferrofluid&qsSearchArea=searchText">ferrofluid; ref="http://pubs.acs.org/action/doSearch?action=search&searchText=ionic+liquid&qsSearchArea=searchText">ionic liquid; ref="http://pubs.acs.org/action/doSearch?action=search&searchText=magnetic+nanoparticle&qsSearchArea=searchText">magnetic nanoparticle; ref="http://pubs.acs.org/action/doSearch?action=search&searchText=dispersion&qsSearchArea=searchText">dispersion; ref="http://pubs.acs.org/action/doSearch?action=search&searchText=stabilization&qsSearchArea=searchText">stabilization