15 Apr 2022

Determination of Nanomaterial Viscosity and Rheology Properties Using a Rotational Rheometer

Abstract: Rheology studies the flow of matter and is one of the most important methods for materials characterization because flow behavior is responsive to properties such as molecular weight and molecular weight distribution. Rheological properties help practitioners understand fluid flow and how to improve manufacturing processes. Rheometers have been extensively used to determine the viscosity and rheological properties of different materials because the measurements are quick, accurate, and reliable. In this standard operating procedure, a general protocol using a rotational rheometer is developed for characterizing rheological properties of nanomaterials. Procedures and recommendations for sample preparation, instrument preparation, sample measurements, and results analysis are included. The procedure was tested on a variety of carbon-based nanomaterials.

27 Jul 2021

Influence of High Volumes of Silica Fume on the Rheological Behavior of Oil Well Cement Pastes

Abstract: Specialized classes of concrete, such as ultra-high-performance concrete, use volumes of silica fume in concrete that are higher than those in conventional concrete, resulting in increased water demand and mixing difficulty. This study considered the effects of eight different silica fumes in three dosages (10%, 20%, 30%) with three w/b (0.20, 0.30, 0.45) on rheological behavior as characterized by the Herschel-Bulkley model. Results indicated that the specific source of silica fume used, in addition to dosage and w/b, had a significant effect on the rheological behavior. As such, all silica fumes cannot be treated as equivalent or be directly substituted one for another without modification of the mixture proportion. The rheology of cement pastes is significantly affected by the physical properties of silica fume more so than any chemical effects.