کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
612219 880693 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Surface structure and properties of mixed fumed oxides
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Surface structure and properties of mixed fumed oxides
چکیده انگلیسی

A variety of fumed oxides such as silica, alumina, titania, silica/alumina (SA), silica/titania (ST), and alumina/silica/titania (AST) were characterized. These oxides have different specific surface areas and different primary particle composition in the bulk and at the surface. These materials were studied by FTIR, NMR, Auger electron spectroscopy, one-pass temperature-programmed desorption with mass spectrometry control (OP TPDMS), microcalorimetry, and nitrogen adsorption. Nonlinear changes in the surface content of alumina in SA and AST and titania in ST and AST samples with increasing oxide content along with simultaneous changes in their specific surface area cause complex dependencies of the heat of immersion in water and desorption of water on heating on the structural parameters. Simultaneous analysis of changes in the surface phase composition, in the concentration of hydroxyls, and in the structural characteristics reveals that at a low content of the second phase the structural characteristics (e.g., SBETSBET) are predominant; however, at a large content of these oxides the phase composition plays a more important role.

Analysis of the surface phase composition, concentration of hydroxyls, and changes in the structural characteristics of mixed nanooxides reveals that at a low content of titania or alumina the structural characteristics are predominant; however, at a large content of these oxides the phase composition plays a more important role.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 314, Issue 1, 1 October 2007, Pages 119–130
نویسندگان
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