کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
609826 880632 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of sodium oleate as a buffer on the synthesis of superparamagnetic magnetite colloids
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Effect of sodium oleate as a buffer on the synthesis of superparamagnetic magnetite colloids
چکیده انگلیسی

In this study, superparamagnetic monodisperse magnetite colloids, around 5 nm in size, were prepared by dissolving iron chlorides, sodium hydroxide (NaOH) and sodium oleate (NaOL), in toluene/ethanol/water mixtures and refluxing for 4 h. The concentrations of NaOH and NaOL were varied to systematically investigate the effect on the surface properties, size, dispersion, and magnetic properties of magnetite nanoparticles (MNPs). The samples were characterized via XRD, FTIR, TGA, TEM, SAED, DLS, and VSM. The results indicated that the surface coatings of MNPs could be manipulated from oleate to hydroxyl groups via increasing the molar ratio of NaOH/Fe(II) more than 8. The amount of NaOH had no obvious influence on the size and the saturation magnetization of MNPs. Therefore NaOH was not a necessary reactant for forming magnetite crystals. On the contrary, NaOL was shown to be the most important component for synthesizing stable magnetite colloids. The NaOL acted as both a key reactant to buffer the pH environment and a surfactant to keep the MNPs stable in nonpolar solvent media.

Sodium oleate exerts an important buffering effect assisting the preparation of superparamagnetic monodisperse magnetite colloids with similar properties.Figure optionsDownload high-quality image (129 K)Download as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 347, Issue 1, 1 July 2010, Pages 1–7
نویسندگان
, , , , , ,