Shear thinning in non-Brownian suspensions. Issue 6 (7th December 2017)

• Record Type: Journal Article
• Authors: Chatté, Guillaume; Comtet, Jean; Niguès, Antoine; Bocquet, Lydéric; Siria, Alessandro; Ducouret, Guylaine; Lequeux, François; Lenoir, Nicolas; Ovarlez, Guillaume; Colin, Annie
• Is Part Of: Soft matter. Volume 14:Issue 6(2018)
• Page Start: 879
• Page End: 893
• Publication Date: 2017-12-07
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c7sm01963g
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : We study the flow of suspensions of non-Brownian particles dispersed in a Newtonian solvent. Abstract : We study the flow of suspensions of non-Brownian particles dispersed into a Newtonian solvent. Combining capillary rheometry and conventional rheometry, we evidence a succession of two shear thinning regimes separated by a shear thickening one. Through X-ray radiography measurements, we show that during each of those regimes, the flow remains homogeneous and does not involve particle migration. Using a quartz-tuning fork based atomic force microscope, we measure the repulsive force profile and the microscopic friction coefficient μ between two particles immersed into the solvent, as a function of normal load. Coupling measurements from those three techniques, we propose that (1) the first shear-thinning regime at low shear rates occurs for a lubricated rheology and can be interpreted as a decrease of the effective volume fraction under increasing particle pressures, due to short-ranged repulsive forces and (2) the second shear thinning regime after the shear-thickening transition occurs for a frictional rheology and can be interpreted as stemming from a decrease of the microscopic friction coefficient at large normal load.