Synthesis of Fe3O4 nanoparticles from emulsions
Synthesis of Fe3O4 nanoparticles from emulsions
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DOI：
10.1039/b100758k
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发表时间：
2001
影响因子：
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通讯作者：
Zuocheng Zhou;John Wang;Xiaowang Liu;H. Chan
中科院分区：
文献类型：
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作者：
Zuocheng Zhou;John Wang;Xiaowang Liu;H. Chan
以少量环己烷为油相，NP 5 + NP 9为表面活性剂相，Fe（II）/Fe（III）盐溶液为水相，设计了一种独特的水包油乳液法合成纳米Fe 3 O 4颗粒。由此从在水相中含有88重量%的0.3M FeSO 4 + Fe（NO 3）3的乳液得到的Fe 3 O 4粉末具有等轴形态和<10 nm的平均粒度。乳液的电导率作为在水相中的Fe 2 +/Fe 3+浓度的函数的研究揭示了NP 5 + NP 9表面活性剂对Fe 2 +/Fe 3+离子的络合作用。因此，所得粒度和形态取决于乳液中表面活性剂和水相的量。强碱性水相有利于Fe_3O_4的形成，而低碱度水相有利于α-FeOOH的形成。磁性测量和穆斯堡尔谱学研究表明，乳液衍生的氧化铁粉末是超顺磁性的，随着测量温度的降低，它变成亚铁磁性。
A unique oil-in-water emulsion route has been devised to synthesize nanosized magnetite (Fe3O4) particles using a small amount of cyclohexane as the oil phase, NP5 + NP9 as the surfactant phase, and a Fe(II)/Fe(III) salt solution as the aqueous phase. The Fe3O4 powder thus derived from the emulsion containing 88 wt% 0.3 M FeSO4 + Fe(NO3)3 in the aqueous phase possesses an equiaxial morphology and an average particle size of <10 nm. Studies on the electrical conductivity of the emulsions as a function of Fe2+/Fe3+ concentration in the aqueous phase revealed the complexation effect of the NP5 + NP9 surfactant towards Fe2+/Fe3+ ions. The resulting particle size and morphology are therefore dependent on the amounts of surfactant and aqueous phase in the emulsion. A strongly alkaline aqueous phase favors the formation of Fe3O4, while a low alkalinity favors the formation of α-FeOOH. Magnetic property measurements and Mossbauer spectroscopic studies indicate that the emulsion-derived iron oxide powder is superparamagnetic, which becomes ferrimagnetic with decreasing measurement temperature.