离子型磁性液体中磁性微粒的TEM分析

The TEM analysis of the magnetic particles' properties in the ionic ferrofluids

将磁性粒子体积分数为１５％和１０％的两种Ｃｏｆｅ３Ｏ４离子型磁性液体静置半年后，为１５％的磁性液体中有沉淀产生．ＴＥＭ分析表明：静置后的两种磁性液体的磁性微粒在物相成分、粒度分布上基本相同，差别表现在团聚程度上——为１５％的磁性微粒大量团聚，而为１０％的磁性微粒则只有少数团聚．可见，团聚是造成为１５％的磁性液体出现沉淀的主要原因．

Two kinds of CoFe2O4 ionic magnetic fluids, with different magnetic Particles volume fraction ψi 15 % and 10%, are discussed. Both of them have self-evolved for half a year in room temperature.As a result of self-evolution, one of them whose is 15 % has many precipitations appearing but the other whose is 10% is still a suspension. The component size distribution and aggregate situation of the magnetie parhcles in these two ionic magnetic fluids are discussed through TEM. As a result, the serious aggregation of the magnetic particles in the ionic magnetic fluids whose is 15 % is the major reason that leads to the precipitations appearance.