کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1484585 991637 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of silica particle structure containing metallocene immobilized by a sol–gel method
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Investigation of silica particle structure containing metallocene immobilized by a sol–gel method
چکیده انگلیسی

A series of homogeneous metallocenes (Cp2ZrCl2, (nBuCp)2ZrCl2, (iBuCp)2ZrCl2, (tBuCp)2ZrCl2, Cp2TiCl2, Cp2HfCl2, EtInd2ZrCl2 and Et(IndH4)2ZrCl2) were immobilized within a silica matrix during its preparation using a non-hydrolytic sol–gel method. Supported metallocenes were characterized by small angle X-ray scattering (SAXS) and nitrogen adsorption. The results show that the silica particle was formed by the aggregation of primary structures having a diameter of about 160 nm. This was a result of the aggregation process, which was affected by the metallocene. This result suggests that the metallocene is surrounded by primary particles deep inside the silica matrix. The low polymer productivity exhibited by the less active metallocene catalysts could be related to the problems of particle fragmentation due to monomer mass transfer limitations along the partially fragmented particle, which would subsequently affect catalytic activity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 354, Issue 33, 1 September 2008, Pages 3973–3979
نویسندگان
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