کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
72046 49009 2016 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of crystal morphology, Si/Al ratio and thickness of an MTW zeolite membrane on water/2-propanol separation by pervaporation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Effects of crystal morphology, Si/Al ratio and thickness of an MTW zeolite membrane on water/2-propanol separation by pervaporation
چکیده انگلیسی


• MTW-type zeolite nanocrystal-layered membrane was successfully prepared.
• The crystal size of MTW zeolite in protection layer could be controlled by using different organic structure directing agents.
• The Al content in MTW crystals of both protection layer and nanocrystal layer affects the performance of the membranes.
• The MTW membranes with a thin thickness presented high water flux.

MTW-type zeolite nanocrystal-layered membranes composed of nanocrystal and protection layers were successfully prepared by a secondary growth method under hydrothermal conditions. The separation abilities of the membranes during pervaporation were investigated by studying the separation of water from water/2-propanol solutions. Both the nanocrystal and protection layers were found to play important roles in the separation process. The crystal size and morphology of the MTW-type zeolite in the protection layer formed on the MTW nanocrystal layer could be controlled by varying the organic structure directing agent (OSDA), such that small crystals approximately 50 nm in size were obtained when using tetraethylammonium bromide as the OSDA. Membranes with nanometer-sized crystals in the protection layer exhibited 4 times higher water flux values and enhanced separation factor as compared with membranes having micrometer-sized crystals. In both layers, zeolite crystals with higher Al contents generated higher water fluxes due to their enhanced hydrophilicity. Moreover, the membranes with nanocrystal layer thicknesses of 7.5, 10, 12 and 17 μm were prepared, and the water flux through the membranes was observed to increase as the nanocrystal layer thickness was decreased.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 222, 1 March 2016, Pages 178–184
نویسندگان
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