کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10377732 880742 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of sodium polyacrylate on the rheology of aqueous Laponite dispersions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Influence of sodium polyacrylate on the rheology of aqueous Laponite dispersions
چکیده انگلیسی
Aqueous Laponite dispersions containing a sodium polyacrylate were analyzed, at fixed ionic strength and pH, by rheometric and electroacoustic (for zeta-potential determinations) techniques at 7 days after their preparation. The rheological behavior of these dispersions was determined by oscillatory and flow experiments. Addition of sodium polyacrylate modifies the interactions between Laponite particles and therefore the physical state of the dispersion. The phase diagram of Laponite dispersion as a function of sodium polyacrylate concentration shows different sol-gel transitions for a specific Laponite concentration as a function of the polyacrylate concentration. Under equilibrium flow conditions the Laponite dispersions fit the pseudoplastic Oswald-de Waele power law model. At the same time, these dispersions show thixotropy, which was analyzed using a second-order kinetic equation. The kinetic processes were characterized by breakdown and build-up parameters, which were found to depend on shear rate. This kinetic equation was modified by a power law exponent of viscosity with shear rate that takes into account the viscosity variations when the shear rates are suddenly changed, in order to fit the hysteresis loops.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 289, Issue 1, 1 September 2005, Pages 86-93
نویسندگان
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