کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5376559 | 1504327 | 2007 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Study of mesoporous silica films by positron annihilation based on a slow positron beam: Effects of preparation conditions on pore size and open porosity
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Positron annihilation spectroscopy (PAS) based on an intense pulsed slow positron beam was applied to the study of mesoporous silica films, synthesized using tetraethyl orthosilicate (TEOS) as the network precursor and a triblock copolymer (EO106PO70EO106) as the structure-directing agent. With positron annihilation lifetime spectroscopy (PALS), pore sizes were obtained from ortho-positronium (o-Ps) lifetimes of the films capped with a 20Â nm thick SiO2 layer. Influences of preparation conditions such as heating, TEOS vapor infiltration and precursor solution ageing on the pore size were studied. Moreover, the effect of ageing of the precursor solution on film pore interconnectivity/open porosity was investigated through lifetime-energy correlation measurements by observing intrinsic annihilation of o-Ps diffused out from the uncapped film surface.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 331, Issues 2â3, 8 January 2007, Pages 213-218
Journal: Chemical Physics - Volume 331, Issues 2â3, 8 January 2007, Pages 213-218
نویسندگان
Chunqing He, Ryoichi Suzuki, Toshiyuki Ohdaira, Nagayasu Oshima, Atsushi Kinomura, Makoto Muramatsu, Yoshinori Kobayashi,