Magnetic Modification of the External Surfaces in the MCM-41 Porous Silica: Synthesis, Characterization, and Functionalization
Magnetic Modification of the External Surfaces in the MCM-41 Porous Silica: Synthesis, Characterization, and Functionalization
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DOI：
10.1021/jp010286
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发表时间：
2001-07
影响因子：
3.3
通讯作者：
A. Bourlinos;A. Simopoulos;and N. Boukos;D. Petridis
中科院分区：
文献类型：
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作者：
A. Bourlinos;A. Simopoulos;and N. Boukos;D. Petridis
浸铁的MCM-41多孔二氧化硅对丙酸蒸气的化学吸附导致生成−丙酸铁物种，该物种在热解时可转化为尺寸均匀的γ-Fe_2O_3纳米粒子(∼150A)，并均匀分散在多孔二氧化硅载体的外表面。考察了羧酸性质对磁性粒子大小的影响。磁性改性的MCM-41固体保持了其结晶度和较大的比表面积，并且可以与各种有机硅配体，例如(CH3O)3SiCH2CH2CH2NHCH2CH2NH2官能化，在不破坏母体材料的磁性的情况下产生新的重构的MCM-41衍生物。通过红外光谱、X射线衍射仪、体磁测量、穆斯堡尔谱、比表面积和透射电子显微镜等手段研究了合成和功能化的各个步骤，以及颗粒的性质、大小和进入最终固体的位置。
Chemisorption of propionic acid vapors by an iron impregnated MCM-41 porous silica leads to the formation of iron−propionate species that upon pyrolysis can be transformed into γ-Fe2O3 nanoparticles of uniform size (∼150 A) and homogeneously dispersed on the external surfaces of the porous silica support. The effect of the carboxylic acid nature on the size of the magnetic particles was examined. The magnetically modified MCM-41 solid retains its crystallinity and large surface area and can be functionalized with various organosilicon ligands, e.g., (CH3O)3SiCH2CH2CH2NHCH2CH2NH2, to produce novel reconstructed MCM-41 derivatives without destroying the magnetic properties of the parent material. The various steps in the synthesis and functionalization, as well as the nature, size, and location of the particles into the final solids were studied by means of IR and XRD, bulk magnetic measurements, Mossbauer, BET, and TEM techniques.