The low-temperature cation-ordered superstructure of anhydrous sodium sodalite, a zeolite with composition Na 6 ͓AlSiO 4 ] 6 , has been determined through the use of both density functional theory ͑DFT͒ and classical force-field lattice energy minimizations. The charge-balancing Na ϩ cations are assumed to occupy their characteristic locations within the cubic alumino–silicate framework near the c...

The weathering of a specimen kaolinite clay was studied over the course of 369 d via solid-state 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy and high-field 27Al MAS NMR. The chosen baseline solution conditions (0.05 mol kg-1 of Al, 2 mol kg-1 of Na+, 1 mol kg-1 of NO3-, 1 mol kg-1 of OH-, and pH approximately 13.8) approximate those of solutions leaking from wa...

Franzinite, ideally [(Na,K)30Ca10][Si30Al30O120](SO4)10•2H2O, a feldspathoid belonging to the cancrinite group, has a tenlayer stacking sequence. Its structure was solved in the space group P321 to an R value of 5.96%. Cell parameters are a 12.916(1), c 26.543(3) Å. The framework, characterized by the stacking sequence ABCABACABC, contains regular alternations of two “cancrinite” and two “sodal...

• The heats of adsorption water and ammonia on MOR with 1 aluminum substitution do not vary much for T1, T2 T4 sites. T3 site shows inverse variation in the ammonia. MFI is also sensitive to distributed at different T-sites. FAU has shown be insensitive regard T-position adsorption. We have investigated MOR, MFI, zeolites acquire a better understanding effect heat microscopic level. performed M...

I n t r o d u c t i o n THE structures of the cancrinite-group minerals are character ized by parallel s ix-membered rings consisting of alternating A104 and SiO4 tetrahedra. The hexagonal symmetry is the result of the stacking of such six-membered rings in an AB... sequence. This stacking leads to large continuous channels that are formed by twelve-membered rings of alternating A1Oa and SiO4 t...

Introduction: The search for the former existence in the Early Solar System of the now extinct radionuclide Cl (T1⁄2 = 3x10 a) has proven to be difficult [e.g., 1]. This is at least partly due to the volatility of chlorine and the fact that in primitive meteorites Cl occurs in high abundance only in alteration phases such as sodalite (Na8Al6Si6O24Cl2). 36-Cl decays to both Ar by β decay (98.1 %...

The structural behavior of a chromate aluminate sodalite, Ca8[Al12O24](CrO4)2, at room pressure and on heating from 463 to 982°C was determined by using in situ synchrotron X-ray powder-diffraction data [ = 0.91997(4) Å] and Rietveld refinements. The sample was heated at a rate of about 9.5°C/min., and X-ray traces were collected at intervals of about 17°C. The structure at 463°C is a modulated...

The diffusion of hydrogen in sodium aluminum sodalite (NaAlSi-SOD) is modeled using classical molecular dynamics, allowing for full flexibility of the host framework, in the temperature range 800-1200 K. From these simulations, the self-diffusion coefficient is determined as a function of temperature and the hydrogen uptake at low equilibrium hydrogen concentration is estimated at 573 K. The in...

The activation of soil-fixed phosphorus is a long-term concern in soil science. In order to enhance the activation effect to soil-fixed phosphorus in red soil, different modified zeolite, through physical, chemical method and the associated both physics and chemistry, was used in this paper. The results showed as following: 1) the activated ability to soil-fixed phosphorus in red soil for modif...