Composition-Dependent Stress Oscillations in a Dilute Suspension under Shear

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Eunhye Jang¹  Hiroaki Koga¹  Hiroyuki Kage¹  Yoshihide Mawatari¹  Masato Yamamura¹ 

[1] Department of Applied Chemistry, Kyushu Institute of Technology

关键词: Colloid;    Depletion Force;    Suspension;    Stress;    Oscillation;    Co-Solvent;   

DOI  :  10.1252/jcej.14we437

来源: Maruzen Company Ltd

【 摘 要 】

References(8)This study presents empirical evidence that dilute particle-polymer suspensions exhibit composition-dependent stress oscillations at constant shear rate. In ethanol/toluene co-solvent suspensions, an increase in the ethanol concentration promoted a transition of the particle-polymer suspension from a stable state, through an oscillating state with well-defined periodicity, toward an unstable mode with multiple frequency peaks. This transition corresponded to increases in the gyration radii of the polymer chains in the fluids. Furthermore, the opposite transition from an unstable state to stable states was observed with increasing polymer concentrations. In contrast, the extent of the transition was curtailed in cyclohexane/toluene suspension, in which both the shear stress and gyration radius remained constant with negligible dependence on the fluid composition. These facts indicate that the non-hydrodynamic deletion attractions among particles play a significant role in influencing the stress instability of polymer-particle suspensions.

【 授权许可】

Unknown