【摘要】 分析了柠檬酸铵(TAC,分散剂)稳定的氧化铝悬浮液的剪切流变行为,研究了TAC加入比例及颗粒大小对流变特性的影响.认为静态时悬浮液中存在由于颗粒布朗运动而形成的热力学颗粒簇,剪切变稀是在剪切作用下热力学颗粒簇分解的结果,而剪切稠化源于剪切作用下水力学颗粒簇的形成.通过悬浮液中颗粒成簇势垒概念的引入,提出悬浮液的低剪粘度和高剪粘度分别取决于氧化铝颗粒表面的ζ电位和Stern电位,通过加入过量的柠檬酸铵可以抑制悬浮液的剪切稠化,推导出了剪切稠化临界剪切速率与颗粒粒径关系的数学表达式.更多还原

【Abstract】 The effect of various contents of dispersant on the rheological behavior of alumina suspensions stabilized with TAC (Tri-Ammonium Citrate) was studied. Based on analyzing the interaction potential among particles in the suspensions, the rheological behavior of suspensions, such as shear thinning and shear thickening, was elucidated. It was considered that there exists particle clusters caused by the collision between particles due to Brownian motion in the static suspensions, and shear thinning is the result of decomposition of thermodynamic clusters while shear thickening is the result of formation of hydrodynamic clusters. The viscosity of alumina . suspensions at low and high shear rate is respectively determined by zeta and Stern potential near the particle surface, and shear thickening behavior can be suppressed with excess TAC amount. At the same time, the critical shear ratesγC (the onset of shear thickening) dependence on the particle size was quantified with a simple shear model.更多还原