Epitaxially Grown Layered MFI - Bulk MFI Hybrid Zeolitic Materials

The synthesis of hybrid zeolitic materials with complex micropore-mesopore structures and morphologies is an expanding area of recent interest for a number of applications. Here we report a new type of hybrid zeolite material composed of a layered zeolite material grown epitaxially on the surface of a bulk zeolite,Material. Specifically; layered (2-D) MFI sheets were grown on the surface of bulk MA crystals of different sizes (300 nm and 10 mu m), thereby resulting in a hybrid Material containing a unique morphology of interconnected micropores (similar to 035 nm) and rnesopores (similar to 3 nm). The structure and morphology of this material referred to as a bulk MFI-layered MFI (BMLM) material, was elucidated by a combination of XRD; TEM, HRTEM, SEM, TGA, and N-2 physisorption techniques. If is Conclusively shown that epitaxial growth of the 2-D layered MFI sheets occurs in at least two principal crystallographic directions of the bulk MFI crystal and possibly In the third direction as well. The BMLM material combines the properties of bulk MFI (micropore network and mechanical support) and 2-D layered MFI (large surface roughness, external surface area, and mesoporosity). As an example of the uses of the BMLM material, it was incorporated into a polyimide and fabricated into a composite membrane with enhanced permeability for CO2 and good CO2/CH4 selectivity for gas separations. SEM-EDX imaging and composition analysis showed that the polyimide and the BMLM interpenetrate into each other, thereby forming a well-adhered polymer/particle microstructure, in contrast with the defective Interfacial microstructure Obtained using bare MFI particles. Analysis of the gas permeation data with the modified Maxwell model also allows the estimation of the effective volume of the BMLM particles, as well as the CO2 and CH4 gas permeabilities of the interpenetrated layer at the BMLWpolyimicle Interface.