氮化硅浆料的胶体特性研究

本文研究了Si3N4浆料的胶体特性,结果表明:Si3N4悬浮粒子的等电点(isoelectric point,简称IEP)在pH=4.2处.分散介质的离子强度影响Si3N4粒子的Zeta电位.分散剂的引入有效地提高Si3N4粒子的Zeta电位,并引起IEP的位移.粉体经不同工艺的预处理后IEP均发生不同程度的位移.X光电子能谱(XPS)分析表面组成发现其IEP的位移与Si3N4粉体表面的氧化程度有关.同时,对Si3N4浆料在不同条件下的分散性进行了考察,表明其分散性与胶体特性具有很好的一致性.

Studies on the Electrokinetics of Silicon Nitride Suspensions

In this paper,the electrokinetics of Si 3N 4 suspensions is investigated.The experimental results indicate that the isoelectric point (IEP) of Si 3N 4 particulates is at the pH value of 4.2.The ionic strength of the dispersing medium has a great influence on the Zeta potential of Si 3N 4 particulates.The introduction of dispersant to Si 3N 4 suspension significantly improves the Zeta potential of Si 3N 4 particulates and shifts their IEP.The shift in the IEP is caused by various pretreatments of Si 3N 4 powders.X-ray photoelectron spectrum (XPS) of Si 3N 4 powders shows that the shift in the IEP is correlative with the oxidizing degree on the surface of Si 3N 4 powders.Acid leaching can improve the Zeta potential,and hence the dispersibility of Si 3N 4 suspensions efficiently.Moreover,the dispersibility of suspensions at various conditions is in good agreement with its electrokinetics.