کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10378492 | 880757 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Adsorption and heterocoagulation of nonionic surfactants and latex particles on cement hydrates
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
شیمی کلوئیدی و سطحی
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چکیده انگلیسی
The adsorption of nonionic surfactants of the alkyl-phenol-poly(ethylene oxide) family and of acrylic latex particles on several anhydrous (but hydrating) or fully hydrated mineral phases of Portland cement was studied. No or negligible adsorption of the surfactant was observed. This was assigned to the ionized character of the surface silanol groups in calcium-silicate-hydrates and to the strongly ionic character of the OH groups in calcium hydroxide and in the calcium-sulfoaluminate-hydrates, which prevents the formation of surface-ethoxy hydrogen bonds. In contrast, provided they are properly stabilized by the surfactant, the latex particles form a loose monolayer on the surface of hydrating tricalcium silicate particles. The attractive interaction between the positive mineral surface and the negative latex surface appears to be the driving force for adsorption. In line with this, adsorption is reduced by sulfate anions, which adsorb specifically onto the silicate surface. Compared to tricalcium silicate, portlandite and gypsum interact only marginally with the latex particles. Our results show that the stability of the nonionic surfactant/latex/cement systems is essentially controlled by the latex colloidal stability and the latex-cement interactions, the surfactant having little direct interaction, if any, with the mineral surfaces.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 281, Issue 1, 1 January 2005, Pages 1-10
Journal: Journal of Colloid and Interface Science - Volume 281, Issue 1, 1 January 2005, Pages 1-10
نویسندگان
Fabrice Merlin, Hicham Guitouni, Hayette Mouhoubi, Sandrine Mariot, Franck Vallée, Henri Van Damme,