کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5365564 1388332 2007 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rapid synthesis of water-glass based aerogels by in situ surface modification of the hydrogels
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Rapid synthesis of water-glass based aerogels by in situ surface modification of the hydrogels
چکیده انگلیسی

The objective of the present research was to reduce the processing time of water-glass based aerogels synthesized via an ambient pressure drying. For this purpose we employed a co-precursor method for the surface modification in hydrogels using trimethylchlorosilane (TMCS) and hexamethyldisilazane (HMDS). The surface modification resulted in the displacement of pore water from the hydrogels and thereby absolutely avoiding the time-consuming solvent exchange step. The attachment of trymethylsilyl (Si(CH3)3) groups to the silica surface was confirmed by the presence of SiCH3 peaks at 2900, 1400, 1255 and 845 cm−1 in the Fourier Transform Infrared (FTIR) spectra. The differential thermal analysis (DTA) revealed that the aerogels maintain their hydrophobic behavior up to a maximum temperature of 500 °C above which they become hydrophilic. The physical and textural properties of the silica aerogels have been reported and the results have been discussed by taking into account the surface modification and the amounts of the pore water displaced out from the hydrogels.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 253, Issue 6, 15 January 2007, Pages 3231-3236
نویسندگان
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