caa a22 4500 605466408 CHVBK 20210128100307.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00397-015-0852-0 doi (NATIONALLICENCE)springer-10.1007/s00397-015-0852-0 Rheology of microgels in single particle confinement [Elektronische Daten] [Bruke Jofore, Philipp Erni, Giovanni Vleminckx, Paula Moldenaers, Christian Clasen] In this work, we investigate the shear rheology of Carbopol 981 microgel particle suspensions, confined between shearing plates with gap separations from 5 to 100 μm. We show that even for confining gaps smaller than that of the gel particle size, the yielding of concentrated microgel suspensions is delayed to stress levels above the bulk yield stress. Furthermore, for stresses below this new yield point, slip is described by elastohydrodynamic lubrication theory as long as the direct confinement of the single gel particles between the shearing surfaces is limited to a Hertzian deformation. For a strong, non-Hertzian particle deformation, the slip layer breaks down and leads to a frictional interaction of the single confined particle with the two shearing surfaces, depending on their surface roughness. Lubrication pressures and friction coefficients have been quantified with in situ normal force measurements on the confined particles, which have also been utilized to unambiguously determine the relevant swollen particle dimensions. Springer-Verlag Berlin Heidelberg, 2015 Thin film rheometry nationallicence Microgels nationallicence Confined flow nationallicence Yield stress nationallicence Jofore Bruke Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut Erni Philipp Firmenich SA, Materials Science Department, Corporate Research Division, 7 Rue de la Bergere, 1217, Meyrin 2 Geneve, Switzerland aut Vleminckx Giovanni Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut Moldenaers Paula Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut Clasen Christian Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut Rheologica Acta Springer Berlin Heidelberg 54/7(2015-07-01), 581-600 0035-4511 54:7<581 2015 54 397 https://doi.org/10.1007/s00397-015-0852-0 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00397-015-0852-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jofore Bruke Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut NATIONALLICENCE 700 1- Erni Philipp Firmenich SA, Materials Science Department, Corporate Research Division, 7 Rue de la Bergere, 1217, Meyrin 2 Geneve, Switzerland aut NATIONALLICENCE 700 1- Vleminckx Giovanni Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut NATIONALLICENCE 700 1- Moldenaers Paula Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut NATIONALLICENCE 700 1- Clasen Christian Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Willem de Croylaan 46, 3001, Leuven, Belgium aut NATIONALLICENCE 773 0- Rheologica Acta Springer Berlin Heidelberg 54/7(2015-07-01), 581-600 0035-4511 54:7<581 2015 54 397