کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
609305 880620 2010 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The rheology of concentrated suspensions of arbitrarily-shaped particles
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
The rheology of concentrated suspensions of arbitrarily-shaped particles
چکیده انگلیسی

We propose an improved effective-medium theory to obtain the concentration dependence of the viscosity of particle suspensions at arbitrary volume fractions. Our methodology can be applied, in principle, to any particle shape as long as the intrinsic viscosity is known in the dilute limit and the particles are not too elongated. The procedure allows to construct a continuum-medium model in which correlations between the particles are introduced through an effective volume fraction. We have tested the procedure using spheres, ellipsoids, cylinders, dumbells, and other complex shapes. In the case of hard spherical particles, our expression improves considerably previous models like the widely used Krieger–Dougherty relation. The final expressions obtained for the viscosity scale with the effective volume fraction and show remarkable agreement with experiments and numerical simulations at a large variety of situations.

Left panel: relative viscosity η(ϕ)/η0η(ϕ)/η0 as predicted by our model for isotropic rods with different aspect ratios and intrinsic viscosities as given by Table 3. Silica rods (solid line), schizophylian (dashed line), xanthan (dotted line), and PMMA fibre (dash-dotted line). Right panel: the same as left panel but assuming orientational order and using ϕmax≃0.9069ϕmax≃0.9069. The fitted values of [ηη] were 90 for silica rods (solid line), 50 for schizophylian (dashed line), 40 for xanthan (dotted line), and 13 for PMMA fibre (dash-dotted line). The data sets were taken from Ref. [9].Figure optionsDownload high-quality image (94 K)Download as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 346, Issue 1, 1 June 2010, Pages 118–126
نویسندگان
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