Thermochemistry of aqueous silicate solution precursors to ..

Aqueous silicate chemistry in zeolite synthesis
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of trapping contaminates in aqueous solutions and can be ..

After cooling at room temperature, the gel was obtained and used as the micro-porous precursor for the synthesis of Y/ZSM-5 composite.The final step involved the synthesis of the composite Y/ZSM-5 molecular sieve having the batch molecular formula;[]22.5427g sodium meta-silicate solution was added to 22ml deionized water and 0.4574g zeolite ZSM-5 (which served as seed for ZSM-5) was added to the resultant mixture, these was aged for 2days at room temperature and served as the structure directing agent for ZSM-5 in the composite with no additional organic template used, italso served as the source of extra silica for the composite, after aging it was introduced drop wise into the micro-porous precursor gel (zeolite Y) from step one and stirred thoroughly for 2 hour [], the pH value of the solution was adjusted to a range of 11.0–11.5 by adding diluted aqueous H2SO4 in drops and stirred thoroughly.

Synthesis and characterization of MCM-49/ZSM-35 composite zeolites in the hexamethyleneimine and cyclohexamine system.
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data relating to silicate species in synthesis ..

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Synthesis of Common Alum mixed with hot, aqueous Sodium Hydroxide solution, dissolving the Aluminum as the Aluminate Ion, Al(OH).
Synthesis of micro-crystals of transparent cobalt aluminate, shrouded in siliceous material, from Co(II)-exchanged zeolite X Matthew Thomas Jamie Lodge a, Peter.
Mesoporous alumina (MA) has attracted much attention because of its potential industrial applications.

Synthesis and Characterization of ZSM-5/β Co-Crystalline Zeolite, Journal of Natural Gas Chemistry14; 95-100.
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Cation exchange properties of traditional aluminosilicate zeolites arise from the isomorphous positioning of aluminium in tetrahedral coordination within their Si/Al frameworks . This imposes a net negative charge of the framework (Si+4 → Al3+) counterbalanced by cations held within the cavities and channels. Ionic character of bonding between interstitial cations and the framework provide facile cation exchange for zeolites with open frameworks, where cations often readily exchanged for other cations in aqueous solution, though in some of the narrow-pored frameworks, such as natrolite, cation replacement is slow and difficult.

Silicate and colloid chemistry in the synthesis of silicalite-1 zeolite from clear solution: ..
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Silicon-29 NMR studies of aqueous silicate solutions

One implication is that, contrary to the traditional picture of zeolite formation from structured ‘secondary building units’ pre-existing in solution, cyclic and cage-like aluminosilicate solute species are not directly involved in the crystallization of solid aluminosilicates such as zeolites from aqueous solutions but simply serve as reservoirs for small, active, acyclic species responsible for crystal growth.">