Rheology of concentrated suspensions of spheres. I. Effect of the liquid—solid interface

Content Provider	Semantic Scholar
Author	Kao, Sheau Van Nielsen, Lawrence E. Hill, Christopher M.
Copyright Year	1975
Abstract	Abstract Coaxial cylinder viscometers were used to measure the rheological behavior of concentrated suspensions of glass spheres in a nonpolar liquid (liquid polybutadiene), a polar liquid (glycerol), and a liquid of medium polarity. The glass beads had untreated surfaces, surfaces with adsorbed octylamine, or hydrophobic surfaces prepared by treating the surfaces with dimethyldichlorosilane. All the suspensions were Newtonian fluids up to volume concentration of 40% except for the suspension of silane treated beads in glycerol, which was pseudoplastic. Contract angle and sedimentation measurements indicated that the glycerol—silane treated beads system contained beads in an agglomerated state. The viscosities of the suspensions obey a Mooney type equation. In the Newtonian systems, all the suspensions containing treated glass surfaces had lower relative viscosities than the analogous systems with untreated surfaces. For suspensions with volume concentrations ranging from 50 to 60% the flow behavior was pseudoplastic in some cases but rigid pastes were observed in other cases. The nature of the particle surface affected the flow behavior in the same manner as at lower concentrations. At still higher concentrations (>60 v/o), a yield stress was found for all systems. Slipping occurred in the viscometer and this phenomenon sets an upper limit for the study of concentrated suspensions.
Starting Page	358
Ending Page	366
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1016/0021-9797(75)90051-X
Volume Number	53
Alternate Webpage(s)	https://apps.dtic.mil/dtic/tr/fulltext/u2/a001344.pdf
Alternate Webpage(s)	https://doi.org/10.1016/0021-9797%2875%2990051-X
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article