Influence of particle shape and sample preparation on shear thickening behavior of precipitated calcium carbonate suspensions

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 32; no. 3; pp. 802 - 809
• Main Authors: Bosco, Alfredo, Paiva, Felipe, Odenbach, Stefan, Calado, Verônica
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2021
• Subjects: Experimental design; Poly(ethylene glycol); Precipitated calcium carbonate suspensions; Rheology; Shear thickening fluids; Shear thickening fluids; Precipitated calcium carbonate suspensions; Experimental design; Rheology; Poly(ethylene glycol)
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2021.01.023

[Display omitted] •Rosette-shaped particles provide discontinuous shear-thickening behavior.•Acicular-shaped particles provide only continuous shear-thickening behavior.•Shear-thickening behavior occurs at lower shear rates with rosette-shaped particles.•Particle concentration is key for observing shear-thickening rheological behavior.•Design of Experiments contributes to reproducible rheological experiments. To more closely bridge the technological advent of shear thickening fluids with material applications, a well-defined sample preparation protocol is needed. In this work, preparation conditions have been studied for suspensions of precipitated calcium carbonate (PCC) particles by means of a 2k Factorial Experimental Design (DOE), with three center points, and as a function of PCC particle shape. Shear thickening maximum viscosity was the response variable and the corresponding analyzed factors were: particle concentration, stirring time, stirring speed and sonication time. Samples with rosette PCC particles exhibited a stronger shear thickening behavior in view of stronger frictional interactions and they also shear thicken at lower shear rates compared to samples with acicular PCC particles. In the case of acicular PCC particles, the shear thickening fluid that provided the highest maximum viscosity ηm was obtained with higher particle concentration, lower stirring speed and shorter sonication time, as acicular PCC particles align more easily in the flow direction. In the case of rosette PCC particles, ηm was achieved with higher particle concentration, longer stirring time and shorter sonication time. Finding optimal sample preparation conditions and particle shapes that take the most advantage of shear thickening behavior is very important for final applications.