The cation exchange capacity (CEC) of montmorillonite (MMT) is 92.6 mequiv/100 g as reported by suppliers. The basal spacing of MMT is 12.1 Å. This MMT was used as such without any further purification. Various amines used as cationic surfactant. ... Cation exchange capacity (CEC) is a measure of the ability of a soil or other porous …
negative charge—called the cation exchange capacity (CEC). A soil with a larger negative charge can retain more positively charged ions and has a greater CEC. ... while for …
Exchange reactions on clay minerals typically show hysteresis effects. This is illustrated in Fig. 12.10.4 for the K + /Ca 2+ exchange on montmorillonite induced by drying. The curves A, B, and C (dotted) represent the exchange of Ca 2+ by K + at three different total concentrations. For K +-montmorillonite that was dried at 80 °C, the …
minerals are characterized by a certain cation exchange capacity (CEC), an important characteristic of minerals that gives the amount of exchange cations (mg equivalent) …
Additionally, because of differences in hydration and surface adsorption, the type of counter-cation has an influence on …
26 rowsMontmorillonite (MMT) is a widely used nanofiller in food packaging films and coatings. It comprises two tetrahedral silica sheets, which are merged with the edge of …
Humus has a CEC two to five times greater than montmorillonite clay and up to 30 times greater than kaolinite clay, so is very important in improving soil fertility. Clay. ... Sand has no capacity to exchange cations because it has no electrical charge. This means sandy soils such as podzolic topsoils have very low CEC, but this can be improved ...
The cation exchange capacity (quantity of cations a soil can adsorb per unit weight, CEC) can be determined using a simple displacement process (Figure 13.1). In step 1, a soil sample is first saturated with a simple …
A realistic charge density-cation-exchange capacity relationship for hec-torite, Otay montmorillonite, and a series of reduced charge montmorillonites of Camp Berteau is obtained by accounting for the influence of particle radius and for the extent of alkyl chains lying outside the clay layers in the charge density calculations.
Cation exchange capacity (CEC) is one of the fundamental properties of clays, the charge on the surface of clay, and provides a means for estimating the …
Modification of the surfaces of montmorillonite (Mnt) by organic molecules is an effective method for improving their affinity toward non-aqueous substances, and has resulted in extensive industrial applications as rheological control agents, drilling fluids, and other functional materials used in applications ranging from environmental remediation …
Cation exchange at clay interfaces mediates a number of fundamental processes while remains poorly understood. Herein, different types of binary A a+ /B b+ …
In the case of soils prevalent with montmorillonite mineral, swelling is possible due to the formation of diffuse double layer and flocculation . Mineralogical characteristics such as MC CC, cation exchange capacity, specific surface area, etc., are the elemental properties that control the mechanical behavior of expansive soils .
This simulation used a homoionic montmorillonite with a layer charge x = 0.5 e/(unit cell), corresponding to ≈ 1.07 e/(nm) 2.The chemical composition per unit cell of this system is represented by the following formula: (3) E 0.5 / m m + ∙ Al 1.5 Mg 0.5 Si 4 O 10 OH 2 ∙ n H 2 O, where m is the valence of counter ion (exchangeable cation) E m+, and …
Source clay SAz-1 from the Clay Minerals Society was used as the sorbent. The fraction of montmorillonite was higher than 98% [26] assuring that adsorption and interaction were restricted to one pharmaceutical compound and one clay phase. Montmorillonite has an expandable layer structure consisting of a gibbsite-like …
It has a low cation exchange capacity and a high alumina content, which makes it useful in ceramics, paper production, and as a filler in plastics and rubber. Montmorillonite: Montmorillonite is a smectite clay mineral that is commonly used in drilling muds, as well as in environmental remediation and as a binder in animal feed. It …
Using montmorillonite (Mt) as the raw material, six kinds of metal cations with different valences (monovalent, divalent and trivalent) are used to modify montmorillonite through interlayer cation exchange and octahedral and tetrahedral central ion (Al 3+ and Si 4+) substitution to obtain the corresponding modified …
A way of determining the cation exchange capacity of montmorillonite by simultaneous thermal analysis is developed using as an example the bentonites of the 10th Khutor deposit (Republic of Khakassia) and the Vodopadnyi area (Sakhalin Island). A correlation is established between the cation exchange capacity of smectite and its …
The cation exchange capacity with single ion exchange capacity illustrates that Mg2+ and Ca2+ do not only take part in cation exchange but also produce physical …
The cation exchange capacity (quantity of cations a soil can adsorb per unit weight, CEC) can be determined using a simple displacement process (Figure 13.1). In step 1, a soil sample is first saturated with a simple cation like NH 4 + so all the negative charge sites are occupied by NH 4 + .
We present a detailed investigation of the molecular structure of montmorillonite, an aluminosilicate clay with important applications in materials sciences, such as for catalysis, drug delivery, or as a waste barrier. Solid-state 29Si, 27Al, 25Mg, and 1H nuclear magnetic resonance (NMR) measurements combined with density functional …
Quaternary ammonium cations with different alkyl-chain lengths have also been used as the interlayer cations in montmorillonite modification. It has been observed that the chain length of the QACs influences the cation exchange capacity of the organo-montmorillonite sufficiently [35].
The cation exchange capacity (CEC), determined by adsorption of [Co(NH3)6] 3+ (Zhu et al., 2007) was 72.4 ... the CEC of montmorillonite has little influence on the maximum basal spacing. On the other hand, the amount of the loaded surfactant strongly depends on the CEC to reach the maximum basal spacing. This is …
We present a detailed investigation of the molecular structure of montmorillonite, an aluminosilicate clay with important applications in materials …
Experimental cation exchange capacities (CEC) of kaolinites were determined and compared to theoretical calculations of CEC. The comparison reveals that the exchangeable cations occur mostly on the edges and on the basal (OH) surfaces of the mineral. It also shows that permanent negative charge from isomorphous substitution of …
The terms of bentonite and montmorillonite have often been used in a same meaning, while bentonite is a term of natural resource and montmorillonite is a name of a clay mineral. The interlayer cation, which compensates the negative charge of the silicate layer, is exchangeable by the reactions in the suspension and in the solid-state [15–17].
Moreover, the evolution of the pore structure of Ca-montmorillonite through ion-exchange reactions with the Ti cations is extremely different from either Fe or Cu cations. Download : Download full-size image; Fig. 3. Pore size distributions of examined montmorillonite samples, where V is the cumulative pore volume (cm 3 /g).
The exchangeability of interlayer cations, through ion exchange, helps in altering the acidic nature. Modified montmorillonite types known as montmorillonite-K-10 (produced by the calcinations of montmorillonite) were found as efficient catalysts. …
Isomorphous substitution is negligible in kaolinite but extensive in montmorillonite; thus kaolinite has much lower charge and cation exchange capacity than montmorillonite. Kaolinite particles tend to be larger than montmorillonite, which gives montmorillonite higher surface area per unit weight than kaolinite.
Montmorillonite is a natural inorganic material of clay category, which is actually layered alumino silicate [150].It has more specific surface area with higher cation exchange capability [154].According to USFDA, montmorillonite is a GRAS material and approved excipient for the use in drug delivery applications [154]. Recently, a flurry of …
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