磁性Fe_3O_4/TiO_2复合颗粒的研制

以纳米Fe_3O_4为磁核,分别采用溶胶-凝胶法和氟钛酸铵还原的液相沉积法制备了高磁性核壳式结构的Fe_3O_4/TiO_2复合颗粒;利用X射线衍射、透射电子显微镜、磁滞回线对制备的复合颗粒进行了表征,并考察了复合颗粒的包覆完整性。表征结果显示,液相沉积法制备的复合颗粒能够将磁核完全包覆。进一步研究了液相沉积法的原料配比、加料方式对复合颗粒的磁性和完整包覆率的影响。实验结果表明,当Fe与Ti的摩尔比为1:0.8且氟钛酸铵溶液和硼酸溶液分4次流加时,制得了高磁性的Fe_3O_4/TjO_2复合颗粒,其完整包覆率为13.4%,饱和磁化强度为22.86 emu/g。

Preparation of High Magnetic Fe_3O_4/TiO_2 Composite Particles

Fe_3O_4/TiO_2 composite particles were prepared using Fe_3O_4 nanoparticles as magnetic core,separately via with by sol-gel method and chemical liquid solution deposition method with reduction of ammonium fluorotitanate.Characterizations by means of XRD,TEM,hysteresis loop and degree of surface coverage illustrated that chemical liquidsolution deposition method wais efficient in covering the surface of Fe_3O_4 cores by with TiO_2.Effects of mole ratio and feeding mode of reactants in chemical solutionliquid deposition method were further studied.Highly magnetic Fe_3O_4/TiO_2 composite particles could be obtained with coverage ratio of 13.4% and saturated magnetization of 22.86 emu/g,when n(Fe):n(Ti) was 1:0.8 by batchwise technique.It is preferred that the solutions containing ammonium fluotitanate and boric acid were added in four-times.