Shear-thickening rheological response of PCC/PEG suspensions

来源期刊：中南大学学报(英文版)2009年第6期

论文作者：杨海林 阮建明 周忠诚 邹俭鹏 伍秋美 谢元彦

文章页码：926 - 930

Key words：precipitated calcium carbonate (PCC) suspension; rheological response; shear-thickening; steady shear; dynamic shear; frequency

Abstract: The steady and dynamic rheological behaviors of precipitated calcium carbonate (PCC) suspension in polyethylene glycol (PEG) were investigated on a TA AR2000ex rheometer. Under steady shear consistency index K and flow exponent N of suspensions with different volume fractions were determined. The shear-thinning and the discontinuous shear-thickening behavior were observed at different constant frequencies from 10 to 100 rad/s. The relationship between the complex viscosity and the constant frequency were determined. As the volume fraction increases, flow exponent N shows a rapid increase, and it increases dramatically when the discontinuous shear-thickening takes place, while consistency index K decreases. Dynamic oscillatory shear experiments were conducted at constant strain amplitude and constant frequency, respectively. For the frequency sweep, the system shows viscous property in entire range of the frequency investigated, and the complex viscosity shows discontinuous jump at a critical frequency of 10 rad/s. For the strain sweep, on the other hand, at low strain the elastic modulus is strongly dependent on the strain, and the viscous modulus is independent of the strain. But at the critical strain point both of the moduli show an abrupt jump and the system transits from elastic to viscous at a strain of 0.1.

基金信息：the National Natural Science Foundation of China