Aluminosilicates water interacting with

Role of alkali and NH cations in the crystallization of ZSM-5 Introduced in an aqueous (alumino) silicate gel (sol), the bare alkali cations will behave in various ways firstly, they will interact with water dipoles and increase the (super) saturation of the sol. Secondly, once hydrated, they will interact with the aluminosilicate anions with, as a result, the precipitation of the so formed gel (salting-out effect). Thirdly, if sufficiently small, they also can order the structural subunits precursors to nucleation species of various zeolites (template function-fulfilled by hydrated Na+ in the case of ZSM-5 (11,48)). ... 

Humus/SOM enter into a wide variety of physical and chemical interactions, including sorption, ion exchange, free radical reactions, and solubilization. The water holding capacity and buffering capacity of solid surfaces and the availability of nutrients to plants are controlled to a large extent by the amount of humus in the solids. Humus also interacts with solid minerals to aid in the weathering and decomposition of silicate and aluminosilicate minerals. It is also adsorbed by some minerals. 

Naturally, structures (d) and (f) do not exhaust all possible states of low-coordinated A1 atoms on the surface of the oxides considered. The calculations, however, seem quite sufficient to suggest that water molecule coordination by a LAS is energetically less favorable for aluminophosphate than for aluminosilicate surfaces. This conclusion is also in accordance with IR data, which indicate that LASs of the both oxides quite similarly interact with pyridine, whereas the LASs of aluminophosphates do not coordinate C02 molecules (136). Indeed, in the case of a sufficiently strong base (pyridine), adsorption interaction appears stronger than the structural coordination and therefore stabilizes the A1 atom in the adsorption state. On the contrary, for C02, which is certainly a very weak base, the interaction is strong enough in the case of aluminosilicates but is insufficient for the adsorption stabilization of aluminum in aluminophosphates. 

Formation of an unreported Na aluminosilicate with approximate composition Nai5Si4Al3O20, and the product of fusion interacted with water, giving aluminosilicate gel, which yielded zeolite P upon hydrothermal treatment. 

The slow reaction process is likely due to multiple factors including (I) hindered reaction kinetics and diffusivity within the viscous gel, (2) inadequate or sluggish dissolution of precursor powder, and (3) a limited potential of iron to form a potassium-based aluminosilicate inorganic polymer. Hematite is not expected to be very soluble in concentrated alkali hydroxide solution, although it dissolution is dependent on the alkali used such that solubility is highest in NaOH, followed by KOH and LiOH. It is expected that as maghemite, magnetite and hematite dissolve, Fe and Fe ions would be released and would then be free to interact with the silica gel. Iron is versatile and can exist in multiple oxidation and coordination states in the final material. In zeolite systems, the more dilute conditions favors the diffusion of iron and other species, and a more thermodynamically stable state can be reached. The use of water-soluble iron sources such as iron nitrate and potassium ferrate in hydrothermal conditions have been shown to be an effective way to produce iron zeolites in which iron is located in tetrahedral coordination. ... 

Clays are aluminosilicates with a two-dimensional or layered structure including the common sheet 2 1 alumino- and magnesium- silicates (montmorillonite, hectorite, micas, vermiculites) (figure 7.4) and 1 1 minerals (kaolinites, chlorites). These materials swell in water and polar solvents, up to the point where there remains no mutual interaction between the clay sheets. After dehydration below 393 K, the clay can be restored in its original state, however dehydration at higher temperatures causes irreversible collapse of the structure in the sense that the clay platelets are electrostatically bonded by dehydrated cations and exhibit no adsorption. 

A hydrothermal solution is a multicomponent system containing com-poimds of Na, K, Si, Ca, Mg, Al, Fe, Cl, S, O, C, B, Li, As, Cu, Zn, Ag, Au, and other elements in ionic and molecular forms. Silicon has one of the highest concentrations. Silica, together with other compounds, passes into this hydrothermal solution due to the chemical interaction of water with aluminosilicate minerals of rocks of hydrothermal fields at a depth in regions of thermal anomalies at high temperatures and pressures. 

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