نتایج جستجو برای: sodalite zeolite
تعداد نتایج: 9098 فیلتر نتایج به سال:
The hydrothermal formation of sodium hydroxyborate enclathrated sodalite synthesized from an initial ternary mixture of mullite, cristobalite and corundum has been investigated. Depending on temperature and pressure the compound Na7-5[AlSi04]6[B(0H)4]1.5 • 2H20 could be synthesized in form of polycrystalline powder as well as in form of single crystals. The kinetics of the sodalite growth could...
Drastic changes can take place in the structure, dynamics, and thermodynamics of a fluid when it is confined to spaces of molecular dimensions, as compared to its bulk counterpart. Water confinement in the nanometer-scale channels and pores of inorganic open framework materials, such as zeolites, are of great scientific interest. Zeolites are crystalline aluminosilicates, with various controlle...
Abstract In this work, three samples of bauxite were used as inexpensive sources for the zeolite formation by a green process based on vapor-phase crystallization (VPC) method. The synthesis was carried out using water bath with deionized heated at 35, 45, 60 or 90 °C. During process, NaOH pre-fused bauxites contacted only vapor from liquid. results indicate that sodalite formed in all after VP...
The utilization of hydroxy sodalite (H-SOD) as catalyst under solvent-free condition is described for the efficient preparation of tetrahydrobenzo[b]pyrans. These compounds are synthesized by three-component reactions of aldehydes, alkylnitriles and dimedone. H-SOD that is the waste-product of zeolite manufacturing process is used as an efficient and a very inexpensive catalyst. Furthermore, it...
To each discrete translationally periodic bar-joint framework C in Rd, we associate a matrix-valued function ΦC(Z) defined on the d-torus. The rigid unit mode (RUM) spectrum Ω(C) of C is defined in terms of the multi-phases of phase-periodic infinitesimal flexes and is shown to correspond to the singular points of the function Z → rankΦC(Z) and also to the set of wavevectors of harmonic excitat...
in this study, a sodalite nanozeolite was synthesized and characterized by x-ray diffraction (xrd) and scanning electronic microscopy (sem). following the morphology evolution of the sodalite nanozeolite in the sem images illustrates the formation of the spherical particle with a size between 60 and 80 nm. then, carbon paste electrode (cpe) was modified by sodalite nanozeolite and ni2+ ions. th...
The archetypal silica- and aluminosilicate-based zeolite-type materials are renowned for wide-ranging applications in heterogeneous catalysis, gas-separation and ion-exchange. Their compositional space can be expanded to include nanoporous metal chalcogenides, exemplified by germanium and tin sulfides and selenides. By comparison with the properties of bulk metal dichalcogenides and their 2D de...
A series of novel rare earth carbonates, RE3(OH)6(CO3)Cl (RE = Dy, Er, Y), with sodalite-like (SOD-like) zeolite topologies have been successfully synthesized by introducing an appropriate amount of CO3(2-) from NaCO3 or atmospheric carbon dioxide as a template. Single-crystal X-ray diffraction reveals that the structure consists of the RE3(OH)6(3+) cationic framework with a SOD-like topology b...
The optical spectra in the UV-VIS region of the hydrated doubly charged tetramer Ag4(2+) and hydrated multiply charged hexamer Ag6(p+) silver clusters encapsulated inside the sodalite cavity of an LTA-type zeolite have been systematically predicted using DFT, TD-DFT and CASSCF/CASPT2 methods. The optical behaviour of the model hydrated clusters [Ag6(H2O)8(Si24H24O36)](p+) is very sensitive to t...
(ABSTRACT) Several novel silica structures have been generated using a simulated-annealing strategy with an ab-initio based covalent-bonding potential. First-principles total-energy pseu-dopotential methods have been used to examine several promising novel structures and to compare their structural parameters, cohesive energies and bulk moduli with those of low-quartz, low-cristobalite, silica-...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید