1. Introduction 1. Introduction Information on mass transport in polycrystalline zeolite membranes is necessary for a theoretical estimation of the membrane performances. Zeolite membranes are usually prepared as thin layer of an assembly of small zeolite crystals including many intercrystalline regions. Thus, the intercrystal region would influence their individual diffusion properties, which ...

Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolid...

Based on recently published papers, this article introduces the characteristics, hydrogen storage capacity, and economic advantages of the adsorptive carbon system, zeolite, and glass microspheres as possible methods of hydrogen storage. The adsorbents for hydrogen storage now available on the market are activated carbon and zeolite. In terms of hydrogen adsorption, zeolite can adsorb 1 wt perc...

Ultrahigh-field 27Al MAS and MQMAS NMR and 129Xe NMR were used to characterize the zeolite-coated SBA-15 materials. This study shows evidence that zeolite nanoclusters are coated on the mesopore surface of SBA-15. These techniques are useful for the detection of zeolite nanoclusters and different aluminum environments in zeolite/aluminosilicate composites, which are difficult or even impossible...

Here we present the one-dimensional (29)Si and (27)Al MAS NMR and two-dimensional (27)Al MQMAS and DQF-STMAS NMR spectra of the monovalent (Na(+), K(+), Rb(+), Cs(+) and NH4(+)) and divalent (Ca(2+), Sr(2+) and Ba(2+)) cation forms of the natural zeolite natrolite (framework type NAT) with complete Si-Al ordering over the crystallographically distinct tetrahedral sites and with the same hydrati...

Abstract The objective of this work was to evaluate the losses N-NH3 by volatilization and agronomic efficiency a mixture urea with natural zeolite, as topdressing fertilization, in an area for commercial production roses (Rosa spp.). treatments were: two rates (60 120 kg ha-1), without zeolite. N sources were applied directly soil surface, determined using free semi-open static chamber. quanti...

2-Ethyl-1,3,4-trimethylimidazolium is so far the fifth and largest imidazolium cation able to produce the pure silica zeolite ITW. The crystallization is not direct, but occurs as an in situ transformation from either the chiral HPM-1 (STW) zeolite or the new layered zeolite precursor HPM-2 (preMTF) and results in large interpenetrated crystals with a habit so far unseen in this zeolite. The re...