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TOWARDS COMMERCIALIZABLE FEATURED ZEOLITES - MESOPOROUS PARTICLES, NANOPARTICLES AND BENDABLE ZEOLITE MEMBRANES

Wang, Bo
http://rave.ohiolink.edu/etdc/view?acc_num=osu1478609347266087

Abstract Details

2016, Doctor of Philosophy, Ohio State University, Chemistry.
Zeolites are inorganic microporous crystalline materials, finding applications in energy and environment related fields. Current zeolite industry mainly involves conventional micron-sized single-crystalline zeolites that have well established production strategies and applications. As reported in scientific research, improved properties of conventional zeolites in specific applications are reached by morphology modifications, like mesoporous zeolite, zeolite nanoparticles and zeolite membranes. From an application point of view, commercializable fabrication and application of these featured zeolites need to be developed. Goal of this dissertation is to develop innovative and industrially practical synthesis methods, morphologies and applications for featured zeolite materials towards commercialization. Mesoporous zeolites have advantage of facilitated mass transport, in which mesopores were conventionally generated by adding organic templates, steam or dealumination. We have developed a facile synthesis method of hierarchical faujasitic structure from a sodium aluminosilicate composition by rational control of nucleation by removal of water via heat from the gel and aging the gel at lower temperatures. By tuning synthesis conditions, nanoparticles of FAU and EMT can be formed that pack together with external surface areas of 249-259 m2/g. Interpenetration packing of the zeolite nanosheets lead to external surface areas in the range of 127-199 m2/g. Thermal and hydrothermal stability as well as the application for 1,3,5-triisopropylbenzene dealkylation were studied. Isolated, colloidal nano faujasites (nanoFAU) have demonstrated extraordinary applications in zeolite membrane synthesis, sensing, catalysis and biomedical diagnostics. Conventional synthesis methods are limited by low yield (typically <10%) and long synthesis time (days). We have invented an innovative synthesis method of colloidal nanoFAU by a dehydration/rehydration hydrothermal (DRHT) process. From a literature reported 3-day aged precursor, nanoFAU with 5% yield is obtained in 96 hours conventionally. A synthesis protocol involving 29 hours of continuous DRHT process with mid-synthesis addition of NaOH over 6 cycles produced pure nanoFAU with a yield of 93%, average particle size of 29±7 nm and Si/Al ratio of 1.76. Overall synthesis rate was ~3% per hour, about 30 times higher than conventional nanozeolite Y synthesis. FAU zeolite membranes have outstanding CO2/N2 separation performance, while long synthesis time (hours to days) and high cost ($5000-$13000 per m2) are limiting their industrial scale preparation and applications. In my PhD research, a polymer supported bendable zeolite membrane platform was developed, in which high reproducibility is realized by growing zeolite layer only within polymer support. Absence of top zeolite layer eliminated the formation of cracks and enables bendability of membrane. With a coating of 200-300 nm PDMS on the zeolite-polymer composite, transport data for CO2/N2 separation indicated separation factors of 35-45, with CO2 permeance between 1600 and 2200 GPU using dry synthetic mixtures of CO2 and N2 at 25 °C. Fabrication of bendable zeolite membrane has also been realized with a roller assembly, which opens up the potential of industrial scale production. To mimic real CO2 capture conditions, influence of humidity on gas separation performance of bendable zeolite membranes was studied with separation conditions optimized in moist feed gas. Highest humidity tolerance is reached at 100 °C with complete polymerization of PDMS.
Prabir Dutta (Advisor)
Susan Olesik (Committee Member)
Yiying Wu (Committee Member)
445 p.
Chemistry
nanozeolite; mesoporous zeolite; zeolite membrane; carbon dioxide separation

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Citations

  • Wang, B. (2016). TOWARDS COMMERCIALIZABLE FEATURED ZEOLITES - MESOPOROUS PARTICLES, NANOPARTICLES AND BENDABLE ZEOLITE MEMBRANES [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1478609347266087

    APA Style (7th edition)

  • Wang, Bo. TOWARDS COMMERCIALIZABLE FEATURED ZEOLITES - MESOPOROUS PARTICLES, NANOPARTICLES AND BENDABLE ZEOLITE MEMBRANES. 2016. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1478609347266087.

    MLA Style (8th edition)

  • Wang, Bo. "TOWARDS COMMERCIALIZABLE FEATURED ZEOLITES - MESOPOROUS PARTICLES, NANOPARTICLES AND BENDABLE ZEOLITE MEMBRANES." Doctoral dissertation, Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1478609347266087

    Chicago Manual of Style (17th edition)

osu1478609347266087
326
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This open access ETD is published by The Ohio State University and OhioLINK.