MgO超细颗粒水分散体系的稳定性研究

Study on the stability of the aqueous dispersion of magnesium oxide ultra-fine particles

研究了影响MgO颗粒在水介质中的分散稳定性的因素,并通过降沉实验和测定颗粒的Zeta电势、颗粒粒度以及分散剂在颗粒/水界面的吸附等温线等来解释相关机理。研究发现,阴离子表面活性剂SDS和阳离子表面活性剂CTAB能够吸附在颗粒/水界面,提高颗粒表面的Zeta电势,增加颗粒间静电排斥效应,从而阻碍颗粒间发生絮凝,提高体系的分散稳定性。而阳离子高分子聚合物聚乙烯亚胺(PEI)在颗粒表面形成多点吸附,从而阻碍其它PEI分子在颗粒表面的吸附,对MgO微粒分散体系的稳定性贡献较小。

The stability of the aqueous dispersion of magnesium oxide microparticles was investigated and the related mechanism was revealed by sedimentation experiment,the measurements of Zeta potential and the size of particle,and the adsorption isotherms of the dispersants at particle/water interface.The results showed that the stability of the MgO aqueous dispersion solution can be increased by adding anionic surfactant SDS and cationic surfactant CTAB adsorbed at the particle/water interface to increase the Zeta potential of the particles to prevent the flocculation of particles.The cationic polymer,polyethylene imine（PEI） can also adsorb at the particle/water interface in the mode of multi-points,and prevent the further adsorption of other PEI molecules,resulting in the lower stability of the dispersion.