氧化铝悬浮液流变性能及空间位阻影响机制

Rheological Properties of Alumina Suspension and Mechanism of Steric Hindrance

聚合物空间稳定机制是陶瓷悬浮液稳定的主要方式。本文以聚合物空间稳定的氧化铝悬浮液为研究对象,通过流变性能测试,研究了悬浮液体积分数、聚合物含量、颗粒粒径对悬浮液弹性模量的影响规律。结果表明,稳态剪切和振荡剪切两种流变测试模式都证明了悬浮液存在明显的弹性特征。确定了对于聚合物稳定的氧化铝悬浮液,影响弹性模量的核心要素为颗粒表面间距,因为颗粒表面间距影响了吸附聚合物的压缩程度。增大悬浮液体积分数、减小颗粒粒径均是通过降低颗粒表面间距以及被压缩吸附层的厚度使系统弹性模量上升,表现为弹性变大,最终影响悬浮液的稳定性。

Polymer steric stabilization is the main mechanism of ceramic suspension stabilization.In this paper,the alumina suspension stabilized by steric mechanism was studied.The influence laws of volume fraction of suspension,content of polymer and particle size on the elastic modulus were studied through rheological property tests.The results indicate that the two rheological testing modes of steady-state shear and oscillatory shear prove that the suspension has obvious elastic characteristics.It is determined that the core factor affecting the elastic modulus of alumina suspension in steric stabilization is the particle surface spacing,due to the particle surface spacing affecting the compression degree of adsorbed polymer.Increasing the volume fraction of suspension and decreasing the particle size both improve the elastic modulus of the system by reducing the particle surface spacing and the thickness of compressed adsorption layer,meanwhile elasticity increases,and the stability of suspension is affected.