Low-field magnetic separation of monodisperse Fe3O4 nanocrystals
Low-field magnetic separation of monodisperse Fe3O4 nanocrystals
复制标题
DOI：
10.1126/science.1131475
复制
发表时间：
2006-11-10
期刊：
影响因子：
56.9
通讯作者：
Colvin, Vicki L.
中科院分区：
文献类型：
--
作者：
Yavuz, Cafer T.;Mayo, J. T.;Colvin, Vicki L.
在极低磁场梯度（< 100特斯拉/米）下的磁分离现在可以应用于各种问题，例如使用点水净化和复杂混合物的同时分离。高表面积和单分散的磁铁矿（Fe 3 O 4）纳米晶体（NC）被证明是响应于低场的大小依赖的方式。颗粒显然在分离中不独立地起作用，而是通过存在于其表面的所得高场梯度可逆地聚集。使用直径为12纳米的Fe 3 O 4 NCs的高比表面积，我们将与从水中去除砷相关的废物的质量减少了几个数量级。此外，磁分离的尺寸依赖性允许通过施加不同的磁场来分离4纳米和12纳米尺寸的Fe 3 O 4 NC的混合物。
Magnetic separations at very low magnetic field gradients (< 100 tesla per meter) can now be applied to diverse problems, such as point-of-use water purification and the simultaneous separation of complex mixtures. High - surface area and monodisperse magnetite (Fe3O4) nanocrystals (NCs) were shown to respond to low fields in a size-dependent fashion. The particles apparently do not act independently in the separation but rather reversibly aggregate through the resulting high-field gradients present at their surfaces. Using the high specific surface area of Fe3O4 NCs that were 12 nanometers in diameter, we reduced the mass of waste associated with arsenic removal from water by orders of magnitude. Additionally, the size dependence of magnetic separation permitted mixtures of 4- and 12-nanometer - sized Fe3O4 NCs to be separated by the application of different magnetic fields.