Temporal interaction of monodispersed microspheres evaluated from steady shear rheometry and onset of flow instability

Abstract

Monodispersed polystyrene microspheres of single micron regime were suspended in mixed media comprising water and ethylene glycol or propylene glycol with varying concentration to accomplish well controlled interparticle interaction. This was experimentally determined via a simple steady shear rheometry. An empirical parameter for the interparticle interaction per collision was determined and compared with the value of total potential energy based on the DLVO theory under the limited interparticle approach. For these purposes, the Hamaker constant was evaluated from experimentally determined contact angle. In the second part of this review, the relationship between the onset of the Taylor instability and interparticle interaction, as well as the effective particle size, is discussed. The effective floc size was revealed to be dominant for the onset of flow instability of the shear flow, leading to the well-grown Taylor vortices.