The effect of suspending medium on the rheological behavior of monodispersed colloidal suspensions was examined to identify the characteristic rheological behavior of concentrated colloidal suspensions. Colloidal suspensions of monodispersed silica particles form colloidal crystals and exhibit shear-thinning flows. With the change of the suspending medium from an aqueous medium to a polyethylene-glycol di-acrylate monomer, both the viscosity of the suspensions and the degree of shear-thinning decreased, and the suspensions exhibited shear-thickening behavior under high shear rates. Additionally, increasing the particle size, critical shear-rate and critical shear-stress at the onset of shear-thickening decreased.
Finally, the research found that shear-thickening becomes more noticeable as the increase in the ethylene-glycol chain lengths of the monomer and the particle size.

Concentrated colloidal suspensions of monodispersed silica particles exhibited shear-thickening when a highly viscous suspending media was prepared using ethylene glycol. Although the shear rate at which shear-thickening occurred decreased in accordance with increases in the suspending media viscosity, the shear stress at the onset of shear-thickening behavior occurred was defined regardless of the suspending media viscosity. In addition, based on the dependence of the critical shear stress on the square reciprocal of the particle size, it was found that shear-thickening behavior can be explained by the diffusion-friction-dominant model.

Broadband dielectric spectrum measurements up to 50 GHz have been conducted for aqueous solution of 2-n-butoxyethanol (2BE) over a wide concentration range to investigate the state of molecular association of 2BE in aqueous solution. All the obtained dielectric relaxation spectra can be well decomposed into multiple Debye-type relaxation functions. The number of necessary relaxation modes clearly depended on the concentration of 2BE and was reasonably correlated with the molecular association state change of 2BE in aqueous solution. The concentration dependence of hydration number per 2BE molecule slightly decreased above a critical concentration for molecular association formation like micelles due to intermolecular hydrogen bonds formation between 2BE molecules.

We have compared the experimental results on solvent squeeze from cylindrical poly(vinyl alcohol) (PVA) gels with the model presented in this paper. The model says that a characteristic time for solvent squeeze, which is also a retardation time of the creep of gels, is proportional to the diameter squared. A simplified version of the model, which is valid when the creep strain is small enough, indicates that retardation time is independent of the applied stress and the height of gels approaches to a constant value in a single-exponential manner. Experiments on PVA gels say that the change in height occurs almost in a single-exponential manner. The retardation time was independent of the applied stress at small stresses but became longer in the high stress region, as in the case of the presented model. The diameter dependence of the retardation time for the PVA gels was weaker than the model prediction. As a whole, the simplified version of the model is useful to explain the squeezing behavior of the PVA gels.