کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
592734 1453915 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Breaking of a cationic amine oil-in-water emulsion by pH increasing: Rheological monitoring to modelize asphalt emulsion rupture
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Breaking of a cationic amine oil-in-water emulsion by pH increasing: Rheological monitoring to modelize asphalt emulsion rupture
چکیده انگلیسی


• Emulsion breakup is the result of the interfacial formulation evolution.
• Rheological behavior evolves from a very shear-thinning to a Newtonian behavior.
• Asphalt emulsions manipulation can be a very complex process.

When a caustic soda solution is slowly added up to a cationic oil-in-water emulsion, prepared with dodecylamine as surfactant, the chemical equilibrium is altered. As a consequence, a progressive viscosity diminution is observed until complete emulsion destabilization. Original cationic emulsions are stable thanks to the droplet electrical double layer formed by the ionized surfactant adsorption on the liquid interface at very low pH values. However, the alkali addition changes the chemical equilibrium in different ways, such as reducing the hydronium ion concentration, allowing for dodecylamine deionization and increasing the ionic species concentration. These changes and the fact that the emulsion's droplet size and distribution remain constant (noticed by granulometric measurements) during the process, let us assuming that viscosity decreases as a consequence of the overall positive layer charge diminution. However, emulsion destabilization can be explained in terms of some formulation parameters such like SAD or HLD. Our system evolves from a very negative to a positive HLD value passing through the optimal formulation when destabilization is observed. An interfacial formulation analysis is presented and a hypothetically extrapolation to asphalt emulsions is briefly analyzed.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 458, 20 September 2014, Pages 63–68
نویسندگان
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