کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
590644 878887 2015 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dynamics of polyelectrolyte adsorption and colloidal flocculation upon mixing studied using mono-dispersed polystyrene latex particles
ترجمه فارسی عنوان
دینامیک جذب پلی یک الکترولیت و فلوکولاسیون کلوئیدی پس از مخلوط کردن با استفاده از ذرات لاتکس پلی استایرن مونو پراکنده
کلمات کلیدی
فلوکولین کلوئیدی، دینامیک جذب پلی الکترولیتی، لایه ایستا متمادی خنثی سازی شارژ، درهم آمیخته شدن
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
چکیده انگلیسی


• Dynamic aspects of polyelectrolyte adsorption and subsequent flocculation are analyzed in terms of collision rate.
• Folding process of polyelectrolyte chain upon collision is revealed as a function of ionic strength.
• Role of protruding chains in the formation of bridging and flat patches in the charge neutralization is clarified.

The dynamic behavior of polyelectrolytes just after their encounter with the surface of bare colloidal particles is analyzed, using the flocculation properties of mono-dispersed polystyrene latex (PSL) particles. Applying a Standardized Colloid Mixing (SCM) approach, effects of ionic strength and charge density of polymer chain on the rate of flocculation, the electrophoretic mobility of particle coated with polyelectrolyte, and the thickness of adsorbed polymer layer were analyzed, focusing on distinguishing features of two modes of flocculation, namely bridging formation and charge neutralization. In the case of excess polymer dosage, the bridging flocculation clearly highlights the transient behavior of polymer conformation from random-coil-like in bulk solution to increasingly flatten on the surface. The adsorption of polymer chains leads to a stagnant layer of solvent near the solid wall, which is confirmed by electrokinetic data. In the regime near optimum dosage two cases emerge. For high charge density polymer, charge neutralization is dominant and advantageous for the continuous progress of flocculation by heterogeneous double layer interaction. As a function of elapsed time after the onset of mixing, crossover from bridging to charge neutralization is found. In the case of low charge density polymer, bridging flocculation is the mechanism. Fluid mixing is concluded to have an essential role in the formation of bridges.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Advances in Colloid and Interface Science - Volume 226, Part A, December 2015, Pages 101–114
نویسندگان
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