Montmorillonite origin

Friebele, E., A. Shimoyana, P. E. Hare, andC.Ponnamperuma. 1981. Adsorption of amino acid enantiomers by sodium-montmorillonite. Origins Life Evol. Biosphere 11 173-184. 

Wang, Guan-Flai. Zhang, Li-Ming. (2007). Reinforcement in thermal and viscoelastic properties of pwlystyrene by in-situ incorporation of organophilic montmorillonite Original, Ap>phed Clay Sdence. 38.17-22. 

Hydrothermal alteration in the Osorezan area is extensive. At the foot of the lava dome, highly silicified alteration occurs. From this zone towards marginal parts, kaolinite zone and montmorillonite zone exist. This type of alteration was caused by the acid hydrothermal solution. But at present such acid hot solutions are not present in the Osorezan area. The acid solution is considered to be of volcanic origin. It is therefore thought that the water chemistry evolved from extremely acid at the early stage to neutral pH at present (Aoki, 1992a). 

The original epoxidation with titanium-tartrate is homogeneous, but it can be carried out heterogeneously without diminishing enantioselectivity by using titanium-pillared montmorillonite catalyst (Ti-PILC) prepared from titanium isopropoxide, (+)-DAT, and Na+-montmorillonite.38 Due to the limited spacing of Ti-PILC, the epoxidation becomes slower as the allylic alcohol gets bulkier. 

A new composite containing montmorillonite and zeolite Beta is prepared by in situ crystallization. Nano-zeolite Beta grows on montmorillonite. The composite possesses a dual system of micropore, originated from zeolite Beta, and mesopore of size around 50nm, due to the abundance of interspace formed by montmorillonite laminaes. Compared with catalyst MoNi/Beta, more i-C8 is produced on catalyst MoNi/composite, when n-Cg is used for feedstock for hydroisomerization. This results from the high diffusion created by composite and the short channel of nano-size zeolite Beta. 

Montmorillonite An iron-rich clay mineral that has a very high cation exchange capacity. Unlike the other clay minerals, a significant amount of sedimentary montmorillonite is hydrothermal in origin. 

Materials. Two montmorillonites of different origins were used in their original forms. Their chemical compositions are reported in Table 1. Sample G, from Greece, is a powder, with particle size in the range 0.1-14 microns. Suspension B is a Volclay montmorillonite, refined by CECA, and formed of particles smaller than 0.5 micron. XRD patterns of these clays made on oriented films showed no detectable contamination with mica. 

Si, Fe and Fe is variable. Illite also appears to be the early product of weathering in cycles of intense alteration or one of the stable products under intermediate conditions (Jackson, 1959). It is apparently stable, or unaffected by transport in rivers for relatively short periods of time (Hurley, et al., 1961) but does change somewhat in the laboratory when in contact with sea water (Carroll and Starkey, 1960) it has been reported to be converted to chlorite or expandable minerals upon marine sedimentation (Powers, 1959). However, Weaver (1959) claims that much sedimentary illite is "reconstituted" mica which was degraded to montmorillonite by weathering processes. It is evident that a certain and usually minor portion of illite found in sedimentary rocks is of detrital origin (Velde and Hower, 1963) whether reconstituted or not. 

It is obvious then that A1 is not synonymous with Fe in sedimentary mica-like minerals. The increasing influence of trivalent iron in a sedimentary system will obviously provoke the crystallization of a specific mineral series which is not contiguous with illite and which would not be present otherwise. The development of glauconite in sediments should be due to specific local conditions which permit the chemical evolution of an initial montmorillonite material to celadonite mica-like phase. In fact previous observations have consistently led to this conclusion as to the origin of glauconite in sediments and sedimentary rocks. 

Arguments have been made by Velde and Hower (1963) against the idea that montmorillonites are simply potassium-stripped micas, this on the basis of mica polymorphs in sedimentary rocks which should reflect the origin of the layer-silicate material. 

One might conclude by saying that the role of montmorillonites in low temperature clay mineral facies is very important. There are, however, several points to clear up, mainly those dealing with the origin of the expanding material, before a complete geochemical cycle can be devised... 

Ethylene and dimethylamine would result successively from the formation of ylide by deprotonation, an intramolecular carbanionic attack, and finally reprotonation. These mechanisms in which the methyl derivatives have been used are different from those proposed for montmorillonite where the ethylammonium cations were mainly implied. The origin of these differences may be partially the reactivity of the hydrogen as well as the nature of the surface acid sites. These considerations prompted us to repeat our previous experiments (1) for ethylammonium-exchanged Y zeolites. 

The reaction schemes 11-18 provide a reasonable explanation for the similar behaviors of Y zeolites and of montmorillonites despite the different origin of their acid properties. 

The points for the two other phases are less reliable. For montmoril-lonite I have only one point—namely, the montmorillonitic fraction Si of Whitehouse and McCarter (23). Griffin and Goldberg (9) have analyzed montmorillonites from the Pacific and found practically the same composition for those of volcanic and eolic origin unfortunately their analyses give only Fe, K, and Ca but not Na or Mg, so they could not be plotted or compared in Figure 2. For phillipsite, finally, the average from the Challenger samples was used (2). 

Original kaolinite Sodium kaolinite Ammonium kaolinite Hydrogen kaolinite Original montmorillonite Sodium montmorillonite Ammonium montmorillonite Hydrogen montmorillonite... 

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