氧化铝微粉-水浓悬浮液流变行为的研究

Study on the Rheological Behavior of the Microalumian Powder Concentrated Suspension

对文题研究表明：氧化铝微粉浓悬浮液属于非聚集性微粉浓悬浮液的胀性流体，随氧化铝微粉浓度增加，临界剪切速率γｃ向低剪切速率方向移动，由于假凝出现剪切中断现象。据该微粉浓悬浮液具有的正负双触变环，表明系统既具有触变性又具有粘弹性。小振幅振荡剪切实验证明，系统粘弹性随浓度增加而增强。借助分子运动论解释了贮能模量Ｇ′和耗能模量Ｇ″与频率ω的关系。

The rheological behavior of microalumina concentrated suspensions was studied.The result showed that the microalumina powder concertrated suspensions are the dilatant fluid of nonaggregating micropowder suspension.With the increase of the concentration of miccroalumina powder,the critical shear rate c of the suspension shifts to the value of lower shear rate.Owing to pseudo aggregation,the rheopexy phenomenon appears.The double thixotropic rings of the microalumina concentrated suspensions indicate that thixotropy and viscoelasticity coexist in this system.Through a small amplitude oscillatory experiment,it was verified that the viscoelasticity of the system increased with the incerase of the concentration of the microalumina concentrated suspensions.The relations of the storage and loss modulus vs.the radial frequency were explained with the kinetic theory of molecules.