We report the synthesis and characterization of a series of new mesoporous zeolite and zeotype materials made available by combining new and improved procedures for directly introducing carbon into reaction mixtures with the fluoride route for conventional zeolite synthesis. The mesoporous materials were all prepared by hydrothermal crystallization of gels adsorbed on carbon matrices which were...

The separation of saturated branched and linear alkanes may be investigated by selective adsorption on microporous organophilic MFI type zeolite. From the literature, adsorption equilibria of mixtures show a favourable selectivity for less branched alkanes [1]. However the separation process is significantly influenced by the transport properties. The knowledge of the transport coefficients of ...

A series of catalysts based on hybrid intergrowth structure zeolites MFI-MEL, MFI-MTW, and MFI-MCM-41 are studied in the reaction olefins synthesis from dimethyl ether at atmospheric pressure a temperature 340 °C. The total acidity zeolite-based is shown to correlate with their activity. However, use zeolite MFI-MCM-41, which characterized by high content medium acid sites, additionally catalyz...

Stable suspensions of zeolite nanosheets (3 nm thick MFI layers) were prepared in ethanol following acid treatment, which partially removed the associated organic structure-directing agent. Nanosheets from these suspensions could then be dispersed at the air-water interface and transferred to silicon wafers using Langmuir-Schaefer deposition. Using layer-by-layer deposition, control on coating ...

mfi zeolite membranes were prepared on porous α-alumina substrates, using secondary growth of nano-seeded layers. the resulting membranes were characterized by means of scanning electron microscopy (sem), x-ray diffractometry (xrd), and pervaporation performance tests for separation of benzene, toluene and xylene (btx) mixture from contaminated water. the morphology, thickness, homogeneity, cry...

An example of zeolite selectivity (MFI → MOR) driven by synthesis aging time has been studied.

The effect of different sizes of structure directing agents on the ordering of the fluoride ions in pure silica MFI zeolites has been determined using magic angle spinning solid state NMR. By synthesizing fluoride containing pure silica MFI zeolites using methyltributylammonium cations as the structure directing agent, it has been possible to change the type of ordering seen for the fluoride io...

Two imidazolium cations containing a benzyl group, 1-benzyl-3-methylimidazolium and 1-benzyl-2,3-dimethylimidazolium, generally produce the large pore zeolite MTW when used as structure directing agents in the synthesis of pure silica zeolites by the fluoride route. When working at low water contents only the smallest of these cations is able to crystallize MFI, a zeolite with crossing medium p...

A new route to the synthesis of highly b-oriented zeolite MFI films is demonstrated for the first time using ammonium salts as crystallization-mediating agents in secondary growth. The ammonium salts tailor the crystallization process and silicate-NH4(+) interactions dominate over TPA-NH4(+) interactions so that nucleation was effectively suppressed during secondary growth.

To control indoor air quality, a novel freon gas sensor of piezoelectric microcantilever coated with zeolite has been developed in this paper. Excited by an ac voltage, the microcantilever is employed to detect the concentration of sample freon-12 gas ranged from 0 to 100 ppm by the effect of the specific MFI zeolite modification. High selectivity and sensitivity combined with excellent repeata...