State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, P.O. Box 98, Beijing 100029, China.
J Colloid Interface Sci. 2012 Feb 15;368(1):97-106. doi: 10.1016/j.jcis.2011.10.056. Epub 2011 Nov 9.
A series of size-controllable hierarchically nanostructured magnetic hollow spheres (MHS) (250-2330 nm) have been fabricated by using the hard-template method involving the coprecipitation of ferrite precursor over the pre-synthesized polystyrene spheres with varied sizes under organic solvent-free conditions followed calcinations. The SEM, TEM and HRTEM results indicate that the primary nanoparticles constructing hierarchically nanostructured MHS clearly show the template sphere size-dependent changes in morphologies and stacking modes from disorderly stacked globular and nanorodlike mixed particles, to orderly perpendicularly oriented nanorodlike particles, and to compact horizontally arranged nanospindle particles as the template size is increased. The N(2) adsorption-desorption data reveal that the MHS spheres have a high BET surface area (48-83 m(2)/g) and large pore volumes (0.37-0.66 cc/g). The vibration sample magnetization analysis shows that the MHS spheres have moderate magnetization saturation of 24-37 emu/g. The adsorption results show that the BSA adsorbance is greatly affected by the varied morphologies and stacking modes of primary nanoparticles constructing the MHS spheres and the maximum adsorption occurs on the MHS spheres mainly comprised of perpendicularly oriented nanorodlike primary particles.
一系列可控制尺寸的分级纳米结构磁性空心球（MHS）（250-2330nm）已通过使用硬模板方法制备，该方法涉及在有机溶剂条件下将铁酸盐前体共沉淀在具有不同尺寸的预先合成的聚苯乙烯球上，然后进行煅烧。SEM、TEM 和 HRTEM 结果表明，构成分级纳米结构 MHS 的初级纳米粒子明显表现出形态和堆叠模式的模板球尺寸依赖性变化，从无序堆叠的球形和纳米棒混合颗粒，到有序垂直定向的纳米棒颗粒，再到模板尺寸增加时的紧密水平排列的纳米纺锤颗粒。N2 吸附-解吸数据表明，MHS 球具有高 BET 表面积（48-83m2/g）和大孔体积（0.37-0.66cc/g）。振动样品磁化分析表明，MHS 球具有中等的磁化饱和度（24-37emu/g）。吸附结果表明，BSA 的吸附受构成 MHS 球的初级纳米粒子的不同形态和堆叠模式的强烈影响，最大吸附发生在主要由垂直定向纳米棒初级粒子组成的 MHS 球上。
