用LB膜技术组装α-Fe_2O_3超微粒的研究

Study of Fabricating α-Fe_2O_3 Ultrafine Particles by Langmuir-Blodgett Film Technology

用超声分散的方法将α－Ｆｅ２Ｏ３超微粒分散于硬脂酸／正已烷／氯仿溶液中，用ＬＢ膜技术进行有序组装。结果显示：α－Ｆｅ２Ｏ３超微粒能均匀地分散在有机溶剂中，α－Ｆｅ２Ｏ３超微粒／硬脂酸单分子膜的成膜性能良好，复合膜中的α－Ｆｅ２Ｏ３超微粒有一定的有序性，α－Ｆｅ２Ｏ３超微粒硬脂酸复合ＬＢ膜具有层状结构。

The α-Fe_2O_3 ultrafine particles were dispersed in the solutions of stearic acid/n-hexand/chloroform by the ultrasonic method,and fabricated by the Langmuir-Blodgett film technology.They were investigated by mearsof π-A isotherms,UV-visible absorption,IR spectrum,Small-angle X-ray diffraction,TEM and electron diffraction.The results showed:The single molecular area of α-Fe_2O_3 ultrafine partiches/stearic acid composite monolager is bigger than that of stearic acid.It is found that the absorption band edges of α-Fe_2O_3 ultrafine particles modificated by stearic acid significantly shift to the red,which is in contrast with that of bulk Fe_2O_3.This is caused by the influence of dielectric confinement effect.There are two grades Brag-peak appeared in the small-angle X-ray diffraction spectra indicated that the α-Fe_2O_3 ultrafine particles/stearic acid composite film had lamellar-structure.The littler orientation can be induced when there are lattic matching relations between stearic acid monolager and α-Fe_2O_3 ultrafine particles.