SURFACE MODIFICATION AND DISPERSION OF NANODIAMOND IN CLEAN OIL

The effect of different kinds of surfactants on the size distribution of nanodiamond particles in clean oil was studied. Results show that the dispersing stability of nanodiamond modified with surfactants YS-1 and SB-18 simulta-neously is much better than those modified with either of them because of synergism of the surfactants. And the particle size distribution in the system can be improved remarkably after the adoption of hyperdispersants such as SA-E and SA-F. Anchoring groups of those hyperdispersants can be bonded with the particle surface by chemical and/or hydrogen bonding and their soluble chains are well compatible with the dispersion media. As a result, the particles are uniformly distributed in the system owing to the steric stabilization. A very stable clean-oil based nanodiamond suspension with an average particle size of around 53.2 nm was prepared.

磁性微粒的表面改性及分散方式对硅油基磁性液体稳定性的影响

以平均粒径约10.8nm、球形Fe3O4微粒为基体材料,用不同的阴离子表面活性剂改性后分散于2-甲基硅油中,根据分散体系透光率值的大小确定适宜的表面活性剂。用过渡液对改性后的磁微粒进行复合包覆,然后分散在2-甲基硅油中可得到硅油基磁性液体。根据磁性液体透光率、饱和磁化强度的不同,考察了Fe3O4微粒的表面改性对稳定性的影响。用正交实验确定了各组分之间的理想配比,探讨了不同分散方式对稳定性的影响。实验结果表明,在Fe3O4微粒粒径一定的条件下,硅油基磁性液体的稳定性主要由过渡液、Fe3O4微粒、表面活性剂三者的用量决定,还与使用的分散方式有关。