Temperature dependencies of 27Al and 23Na nuclear magnetic resonance spectra and spin-lattice relaxations in mordenite have been studied in static and magic angle spinning regimes. Our data show that the spin-lattice relaxations of the 23Na and 27Al nuclei are mainly governed by interaction of nuclear quadrupole moments with electric field gradients of the crystal, modulated by translational mo...

Ion exchange properties of five different Japanese natural zeolites in seawater were examined. Sodium ions could be reduced by all zeolites, although anions, Cl(-) and SO(4)(2-), in seawater showed barely changes. Natural zeolite desalination treatment mainly depends on the ion exchange between Na(+), K(+) and Mg(2+) in seawater and Ca(2+) in natural zeolite. This study found that mordenite ...

Varying the extraframework metal cation on alkali exchanged mordenite tunes ethanol dehydrogenation properties of ZnO supported mordenite, resulting in enhanced lifetime, low ethylene selectivity and increased acetaldehyde productivity per Zn.

Ammoniacal nitrogen (ammonia and ammonium) in agricultural wastewaters can promote eutrophication of receiving waters and be potentially toxic to fish and other aquatic life. Zeolites, which are hydrated aluminum-silicate minerals, have an affinity for ammonium ions (NH4"") and are, therefore, potentially useful in removing this contaminant from wastewaters. The major objectives of this study w...

The adsorption of alkanes and alkenes on zeolites is investigated by comparing the adsorption characteristics for three types of zeolite: ferrierite, ZSM-5, and mordenite. The activation energy for the diffusion of propane and n-butane on ferrierite and the heat of adsorption of C(2)-C(4) alkanes and alkenes on zeolites and silica are estimated based on Fourier transform infrared spectroscopy, ...

The plasma-catalytic oxidation of soot was studied over zeolite-supported vanadium catalysts, while four types zeolites (MCM-41, mordenite, USY and 5A) were used as catalyst supports. rate followed the order V/MCM-41 > V/mordenite V/USY V/5A, 100% achieved at 54th min reaction V/mordenite. CO2 selectivity process follows opposite V/M catalyst. A wide range characterizations including N2 adso...

The development of optical gain in chemically synthesized semiconductor nanoparticles (nanocrystal quantum dots) has been intensely studied as the first step toward nanocrystal quantum dot lasers. We examined the competing dynamical processes involved in optical amplification and lasing in nanocrystal quantum dots and found that, despite a highly efficient intrinsic nonradiative Auger recombina...

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. ...

A zeolite (mordenite)-pore-phenol resin composite and a zeolite-pore-shirasu glass composite were fabricated by hot-pressing. Their thermal conductivities were measured by a laser flash method to determine the thermal conductivity of the monolithic zeolite with the proposed mixing rule. The analysis using composites is useful for a zeolite powder with no sinterability to clarify its thermal pro...