the main goal of this work was to synthesize and evaluate the effect of dehydration temperature on the potential application of hydroxy sodalite zeolite membrane. hydroxy sodalite zeolite membranes were synthesized via direct hydrothermal method onto a tubular alumina support without seeding in a hot air oven. the synthesized membranes were characterized by x-ray diffraction (xrd) and scanning ...

In this work, the main aspects regarding the permeation of mixtures containing CO2 and permanent gases such as H2 , N2 and CH4 through zeolite membranes have been investigated, focusing on the description of the mass transport mechanisms taking place inside the pores. First, a brief overview about the performance of the main zeolite membranes used in gas separation (e.g. DDR, CHA, AEI, FAU, etc...

Measurement by impedance spectroscopy of the changes in intrazeolitic cation motion of pressed pellets of zeolite particles upon adsorption of dimethylmethylphosphonate (DMMP) provides a strategy for sensing DMMP, a commonly used simulant for highly toxic organophosphate nerve agents. In this work, two strategies for improving the impedance spectroscopy based sensing of DMMP on zeolites were in...

─The Nafion/zeolite composite membranes were synthesized for polymer electrolyte fuel cells (PEMFCs) by adding zeolite in the matrix of Nafion polymer. Two kinds of zeolites, Analcime and Faujasite, were used. The physicochemical properties of the composite membranes such as water uptake, ion-exchange capacity, hydrogen permeability, and proton conductivity were determined. The fabricated compo...

Layers of high silica zeolites, synthesized with an organic structure directing agent (OSDA) and grown onto porous support structures, frequently suffer from the thermal stress during the removal of OSDA via the calcination process. The different thermal expansion coefficients of the zeolite and the support material, especially when stainless steel is used as a support, causes enormous tension ...

Zeolites are crystalline microporous materials with well-defined and uniform pore structure that find extensive industrial uses as adsorbents, catalysts and ion exchangers [1-2]. Zeolite films supported on different materials have been successfully prepared and have potential applications as highly selective membrane separators, membrane reactors, chemical sensor and microdevices [3-10]. Most o...

Zeolite NaA-type membranes hydrothermally synthesized on porous alumina tubes, for dehydration process, were characterized by grazing incidence 2 theta scan X-ray diffraction analysis (GIXRD). The fine structure of the membrane was studied fractionally for surface layer and for materials embedded in the porous alumina tube. The thickness of the surface layer on the porous alumina tube in the me...

The permeability of reverse osmosis membranes is limited by the diffusive transport of water across a non-porous polyamide active layer. Alternatively, fabricating a microporous active layer capable of rejecting salt ions while allowing for water transport would increase the permeability while maintaining high salt rejection. Zeolites provide a model porous network which is capable of performin...

A new SUZ-4 zeolite membrane with tetraethlyammonium hydroxide as the template was fabricated on mullite tube via hydrothermal sol-gel synthesis in a rotating autoclave reactor. The suitable synthesis condition was SiO2:Al2O3 ratio of 21.2 for 4 days at 155 °C crystallization under autogenous pressure. The obtained SUZ-4 possessed a high BET surface area of 396.4 m/g, total pore volume at 2.611...

A Novel modified Analcime (Na16 (Al16Si32O96) •16H2O) zeolite with a new molar ratio have been successfully synthesized. In order to investigate the role of the template, Different samples were synthesized with and without Tetramethylammoniumhydroxide (TMAOH) template through hydrothermal method. Different synthesis times (24, 36 and 72 hours) and molar ratios have been utilized. The optimum sa...