A discussion of various strategies for the intrazeolite encapsulation of polymer filaments is given. Two examples are discussed in more detail: Poly(2-ethylaniline) and pyrolyzed polyacrylonitrile in zeolite hosts. Poly(2-ethylaniline) chains were synthesized within the three-dimensional channels of dehydrated zeolites X and Y via oxidation of the intrazeolite monomers with aqueous (NH4)2S20s. ...

In this work, a new synthesized Y-type zeolite with an Si/Al molar ratio of 2.5 (NaY) was modified with amines, in order to probe the influence of the modification of the adsorbent’s surface on CO2 adsorption. The three selected amines were diethanolamine, tetraethylenepentamine, and 2- methylaminoethanol. The surface nature of NaY was changed after amine modification, which causes a...

Thermal decomposition in a thermobalance of Fe(CO), adsorbed on alkali-metal, hydrogen-Y, dealuminated Y, L and omega zeolites proceeds stepwise via slow decarbonylation at low and high temperatures, separated by a fast endothermic reaction. Average CO/Fe ratios have been determined after each step. From i.r. results the former intermediates are assigned to species bearing bridging CO, whereas ...

Molecular dynamics (MD) simulation of non-rigid H-Y zeolite framework are performed at 298.15 and 5.0 K. Usual bond stretching, bond angle bending, torsional rotational, and non-bonded Lennard-Jones and electrostatic interactions are considered as intraframework interaction potentials. Calculated atomic parameters are in good agreement with the experiment, which indicates the successful reprodu...

Environmental and/or occupational exposure to minerals, metals, and fibers can cause lung diseases that may develop years after exposure to the agents. The presence of toxic fibers such as asbestos in the environment plus the continuing development of new mineral or vitreous fibers requires a better understanding of the specific physical and chemical features of fibers/particles responsible for...

this work undertakes the study of the detoxification reactions of o, s-dimethyl phosphoramidithioate (methamidophos) as an organophophorus insecticide on the 14.7 wt% magnetite (fe3o4) nanoparticles/ag-nay faujasite molecular sieve zeolite (fmsz) composite. the influence of solvent (methanol, acetonitrile and n-hexane) on the detoxification potential of composite was investigated. for this surv...

N,N,N-Trimethylanilinium cations were synthesized on acidic zeolite H-Y by direct reaction of N,N-dimethylaniline and methanol. Time-resolved observation of the detailed decomposition process of N,N,N-trimethylanilinium cations was achieved by in situ 13C stopped-flow (SF) MAS NMR spectroscopy at reaction temperatures of 498 K to 573 K.

The ion exchange of Na for Cr/K, Cr/Mg and Cr/Ca in Y and X zeolites was studied using breakthrough curves. It was observed that Cr ions were able to remove some competitive ions that had already been exchanged at the zeolitic sites, producing a sequential ion exchange. Some mass transfer parameters such as length of unused bed, overall mass transfer coefficient, operational ratio and dimension...

One of the most attractive properties of zeolites are their well organized nanopores and nanochannels which serve readily as supporting hosts for various molecules. Encapsulation of catalytically active transition metal complexes inside the nanopores of zeolites, often referred to as ‘ship-in-a-bottle’ systems,1 has been believed to be one of the most promising strategies in the development of ...

In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount of Na+ adsorption on 4A, X, Y, Na-P1 and mordenite type zeolites were determined in aqueous media, in a two-cation (Na+ and H+)...