The Influence of Continuous Shear, Shear History and Relaxation on the Rheological Behavior of Sio2/Glycerine Suspensions

Applied Rheology

Zeng Guangsheng¹  Liu Wenyong¹  Chen Yi¹  Li Xianggang¹ 

[1] Key Laboratory of Advanced Materials and Technology for Packaging of Hunan, Hunan University of Technology,Zhuzhou412008, P. R. China;

关键词: sio2;    glycerine;    shear-thickening;    shear history;    steady shear;    dynamic oscillation;   

DOI  :  10.3933/applrheol-25-44806

来源: DOAJ

【 摘 要 】

Suspensions of SiO2 microspheres in glycerine exhibit drastic shear-thickening behavior under steady shear and dynamic oscillatory shear test. The rheological behavior of suspensions agrees with the modified Cox-Merz rules as the dynamic oscillatory rheological behavior at low frequency could be reasonably interpreted in terms of the steady shear behavior. As new insight, the effect of shear history and the relaxation on the rheological behavior was investigated in detail. The result showed that under continuous shear, the viscosity decreases after a “pulse”: The degree of decrease is directly proportional to the shear rate. Similar phenomenon is also found under the continuous stress and dynamic oscillatory shear rate sweep. The shear history shows a non-negligent effect on the rheological behavior, the suspensions with higher viscosity show a lower viscosity under the same shear rate. Moreover, the relaxation time of suspensions shows the direct dependency on the initial viscosity, while the volume fraction of suspensions also affect the relaxation time. For more enlapsed times, also longer relaxation times are needed for the suspensions with lower volume fraction and higher initial viscosity.

【 授权许可】

Unknown