pH对水基Al2O3/SiC二元悬浮液流变性的影响

摘要

The dispersion and stability of Al2O3 suspensions and SiC suspensions have been investigated by measuring zeta potential and rheology at pH 3.0-12.0. Based on the above experiment, the rheological properties of the binary suspensions of Al2O3/SiC were tested as a function of pH. It was found that the dispersion stability of the binary suspensions was strongly dependent on pH. At pH≤3.0, the binary system with opposite charged Al2O3 and SiC particles was well-dispersed and not lfocculated. At pH 3.0-9.0, similar to the unary SiC suspensions, the Al2O3/SiC binary suspension was strongly lfocculated. At pH 9.0-12.0, the stability of the SiC component seemed to dominate the overall rheological behavior of the Al2O3/SiC binary suspensions, and theAl2O3/SiC binary system and SiC suspensions were well-dispersed.%在pH 3.0-12.0范围内，对Al2O3和SiC颗粒的zeta电位及其一元悬浮液流变性进行了测试。在此基础上，着重研究了Al2O3/SiC二元悬浮液的流变性。结果表明：在不同的pH段，该二元系统悬浮液表现出完全不同的流变性特征：当pH≤3.0时，尽管Al2O3颗粒表面带正电荷，SiC颗粒表面带负电荷，Al2O3/SiC二元系统并未产生强烈的絮凝，悬浮液仍处于稳定的分散状态；当pH值在3.0-9.0区间内，二元悬浮液表现出与SiC一元悬浮液相似的流变性质,产生了强烈的絮凝；而在pH值为9.0-12.0区间内，二元悬浮液与SiC一元悬浮液的流变特性更加接近，表明在碱性条件下，SiC颗粒的分散状态对二元悬浮液的流变性起主导作用，悬浮液整体处于高度的分散状态。