کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1297831 1498361 2009 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Redox reactions and inward cationic diffusion in glasses caused by CO and H2 gases
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Redox reactions and inward cationic diffusion in glasses caused by CO and H2 gases
چکیده انگلیسی

We find that inward diffusion of network-modifying cations can occur in an iron-containing silicate glass when it is heat-treated in CO/CO2 (98/2 v/v) or H2/N2 (1/99 v/v) gases at temperatures around the glass transition temperature. The inward diffusion is caused by the reduction of ferric to ferrous ions and this diffusion leads to formation of a silica-rich surface layer with a thickness of 200–600 nm. The diffusion coefficients of the network-modifying divalent cations are calculated and they are different for the glasses treated in the CO and H2 gases. At the applied partial pressures of CO and H2, the H2-bearing gas creates the silica-rich layer more effectively than the CO-bearing gas. The layer increases the hardness and chemical durability of the glass due to the silica network structure in the surface layer.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solid State Ionics - Volume 180, Issues 17–19, 16 July 2009, Pages 1121–1124
نویسندگان
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