کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9781265 1510835 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Comparative characteristics of texture and properties of hybrid organic-inorganic adsorbents functionalized by amine and thiol groups
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Comparative characteristics of texture and properties of hybrid organic-inorganic adsorbents functionalized by amine and thiol groups
چکیده انگلیسی
The structure and texture characteristics of the hybrid organic-inorganic adsorbents, which were obtained by using of two-component systems of “structure-forming agent/trifunctional silane”, are compared as follows: the first component is Si(OC2H5)4 or (C2H5O)3Si-A-Si(OC2H5)3, where A = -(CH2)2- or -C6H4-; the second one is alkoxysilane with amine (-NH2, NH, -NH(CH2)2NH2) and thiol (-SH) groups. The adsorbents, derived from TEOS, have more accessible functional groups (2.6-4.2 mmol/g) than xerogels, which are based on bis(triethoxysilanes) (1.0-2.6 mmol/g). On another hand xerogels derived from bis(triethoxysilanes) have a more extended porous structure (Ssp =516-968 m2/g, Vs = 0.418-1.490 cm3/g, d = 2.5-15.0 nm) than those that are based on TEOS (Ssp = 4-631 m2/g, Vs = 0.005-1.382 cm3/g, d = 2.3-17.7 nm). The geometric dimensions of functional groups have a more essential effect on the parameters of porous structure in the case of TEOS-derived xerogels. Using solid-state NMR spectroscopy, it has been shown that in synthesis of xerogels with the use of TEOS, the molecular frame of globules is formed by structural units Qn (n = 2,3,4), and the functional groups exist as structural units of Tn (n = 2,3). The xerogels obtained with using bis(triethoxysilanes) consist only of structural units of Tn-type (n = 1,2,3).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Solid State Chemistry - Volume 33, Issues 2–4, 2005, Pages 179-186
نویسندگان
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