| A new system based on dimethylacetamide?DMAc?,ethanolamine?ETA?and azobisisobutyronitrile?AIBN?was employed to synthesize porous Fe3O4 magnetic nanopartiles?Fe3O4 MNPs?with modified surface for the first time.The effects of different reaction temperature,different reaction time and different reactant concentration?ETA,AIBN?on the morphology and adsorption properties of Fe3O4 MNPs were studied,the formation mechanism of Fe3O4 MNPs was also investigated.The property and structure of as-prepared Fe3O4 MNPs were characterized in detail by X-ray powder diffraction?XRD?,transmission electron microscopy?TEM?,scanning electron microscope?SEM?,nitrogen adsorption-desorption measurements and magnetic measurements,etc.Firstly,Fe3O4 were prepared at higher concentration of ETA,it showed irregular lump morphology,and so lower ETA concentration conditions were studied.Secondly,under the condition of lower concentration ETA,the effects of temperature and AIBN on the morphology and adsorption properties of Fe3O4 MNPs were studied.The results showed that the adsorption rate of Fe3O4 MNPs were the highest when the reaction temperature was 14?.The MNPs prepared without AIBN showed an irregular assemble morphology under 140?.After AIBN was added,N2 gas and radical were produced by its thermal decomposition in the system.The increased gas pressure enhanced the growth of nano-units and its self-assemble structure,which leaded to microsphere morphology composed of nano-units with larger size.The radical caused a modified surface.Finally,the adsorption performance of Fe3O4 MNPs to methyl orange solution?MO?was investgated.It proved that the modified surface is the only reason for the adsorption behavior of Fe3O4 MNPs irrespective of the surface area.MNP?3?prepared at a high AIBN ratio showed a high adsorption stability at acidic condition and can be regenerated for dye adsorption applications.Its adsorption isotherm followed the Langmuir model,and adsorption kinetics followed a pseudo-second-order model. |
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