Montmorillonite


Also found in: Dictionary, Acronyms, Wikipedia.

montmorillonite

[‚mänt·mə′ril·ə‚nīt]
(mineralogy)
A group name for all clay minerals with an expanding structure, except vermiculite.
The high-alumina end member of the montmorillonite group; it is grayish, pale red, or blue and has some replacement of aluminum ion by magnesium ion.
Any mineral of the montmorillonite group.

Montmorillonite

 

(named after the French city Montmorillon in Vienne Department), a clay mineral of the lamellar silicate subclass. It has a variable chemical composition, (Ca, Na)(Mg, Al, Fe)2[(Si, Al)4O10] (OH)2nH2O. Its structure is characterized by the symmetrical arrangement of lamellar aggregates (as in pyrophyllite). Interlaminar water molecules and atoms constituting exchange bases (for example, Ca and Na) are distributed between the pyrophyllite sheets. The lamellar aggregates are located at a considerable distance from each other. The mineral forms compact argillaceous masses. Monoclinic crystals rarely occur and can be seen only through an electron microscope; irregular sheets are most commonly observed.

Montmorillonite is white, pink, blue-gray, brown, red, or green, depending on the admixture content. Its hardness on Mohs’ scale is approximately 1, and its density is about 1,800 kg/m3. When wet, the mineral swells considerably as the water penetrates the interlayer spaces.

Montmorillonite is a typical product of aluminosilicate erosion under alkaline environmental conditions. It is the dominant mineral in bentonite and is present in soil, detrital loam, and other sedimentary rocks. Montmorillonite is an extremely valuable mineral. It is an active component of bleaching clay and fuller’s earth, which are used in the petroleum, textile, and soap industries for their adsorptive and saponifying properties.

V. P. PETROV

montmorillonite

One of the common clay minerals which typically swells upon wetting and becomes soft and greasy.
References in periodicals archive ?
The same result has been observed for other polymer/Na montmorillonite nanocomposite membrane where it would take only a small amount of the undispersed organoclay to create the effects that were observed for tensile strength and strain at break [14].
However, to our knowledge the published literature shows that no experimental data regarding the effect of Cetylpyridinium Chloride (CPC) modified Montmorillonite (MMT) clay on the thermal, morphological and rheological studies of PEO/Salt and PEO/PMMA/Salt system has been reported so far.
The organoclays used as fillers were natural montmorillonites modified by pillaring agent (Nanomer I.
As stretching increases, the material surface becomes significantly rough; that is, the structure of oriented bumps and cavities occurs, and effects of palygorskite bending and montmorillonite separation increase.
The nanocomposite prepared by dispersed the montmorillonite into water-bearing Co[Fe.
Natural montmorillonite particles with average size of 12 [micro]m were used as inorganic solid stabilizer for styrene in water.
Evaluations confirmed that the diameter of titanium dioxide nanoparticles has decreased from 70 to 50 nm after the stabilization on montmorillonite particles.
The objectives of this study were (i) to investigate the mechanisms of PAM adsorption and desorption by pure kaolinitc and montmorillonite specimens as well as the ability of PAMs to flocculate the two clays, and (ii) to further test and evaluate the ability of PAMs to clarify and flocculate clay suspensions of four natural subsoils having distinct clay mineralogy.
Removal of methylene blue from colored effluents by adsorption on montmorillonite clay.
Mechanism of palm oil bleaching by montmorillonite clay activated at various acid concentrations.
Montmorillonite can adsorb organic materials either on its surface or within its inter-laminar spaces by an exchange of cations present in these spaces (Phillip et al.
Several samples from Russian deposits enriched with montmorillonite were studied as well.