Interconnection between the Structures and Sorption Characteristics of Mesophase Materials of MCM-41 Type Containing Alkylpyridines

Under the conditions studied for the synthesis of mesophase materials with alkylpyridinium halides an increase in the density of packing of these molecules in the encapsulated micelles was observed with an increase in the length of the alkyl radicals. The difference in the density of packing of these surface active reagents (SAR) depended to a considerable extent on the perfection of the hexagonal structure and the characteristic absorption properties of the mesophase materials of MCM-41 type.     

Siliconizing as a method for the production of acid-resistant modifications of faujasite

It was shown that acid-resistant modifications of faujasite can be produced by its thermal treatment in silicon tetrafluoride vapor if the ratio of the atoms in the zeolite framework is increased as a result of such treatment to Si/Al 12. At lower degrees of isomorphous substitution of the atoms. the faujasite crystal lattice is destroyed in a 5 M solution of hydrochloric acid as a result of the low acid resistance of the aluminum-oxygen tetrahedra of the zeolite and of the imperfections in its structure.L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Kiev. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 1, pp. 51–54, January–February, 1996. Original article submitted March 20, 1995.     

Effect of the structure of bridging ligands on the structure and adsorption properties of 3D-coordinated copper(II) and cobalt(II) formate polymers

Increasing length of the bipyridyl bridging ligands in a series of similar complexes facilitates the formation of microporous coordination polymers. The structure of one of these compounds was found by the Rietveld method. These compounds were found to differ in their adsorption caparcities relative to methanol, nitrogen, and hydrogen. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 1, pp. 39–43, January–February, 2006.     

The Relation between the Efficiency of an Adsorbent in a Refrigeration System and Its Hydration Isotherm

The efficiencies of various types of silica gels, zeolites, and crystalline microporous aluminophosphates in adsorption systems of refrigeration have been determined. On the basis of the results obtained a method is proposed for the determination of the efficiency of an adsorbent from its hydration isotherm without experimental determination of the temperature dependence of the adsorption equilibrium parameters.     

Features of the Distribution of Aluminum in Mordeniteclinoptilolite Catalysts for the Hydroisomerization of n-Hexane

The content of tetrahedral, extraskeletal, and ion-exchanged aluminum in zeolites consisting of natural and decationized forms of mordeniteclinoptilolite rocks after acidic activation were studied. The results were compared with acidity and catalytic activity properties of modified samples of rocks and synthetic mordenite in the hydroisomerization of n-hexane.     

Limiting instrumental function of the Fabry-Perot interferometer

Journal of Applied Spectroscopy -     

Effect of heat-treatment conditions and crystal composition on the heat resistance of AlPO4-5 aluminophosphate

Isomorphous substitution of atoms (AlP 2Si) in the framework of AlPO₄-5 aluminophosphate and the presence of a template in intracrystalline channels inhibit structural transformations of the aluminophosphate during heat treatment in air and in an atmosphere of saturated water vapor. The effect is due to increasing resistance of T-O bonds in tetrahedra of the aluminophosphate framework to rupture.Translated from Teoreticheskya i Éksperimental'naya Khimiya, Vol. 30, No. 4, pp. 211–214, July–August, 1994.