Permeability and frictional strength of cation …
Additionally, because of differences in hydration and surface adsorption, the type of counter-cation has an influence on …
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Thermodynamic and kinetic understanding of cation …
Cation exchange at clay interfaces mediates a number of fundamental processes while remains poorly understood. Herein, different types of binary A a+ /B b+ …
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Cation exchange capacity
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 ...
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Influence of inorganic and organic salts on the hydration …
However, previous studies on montmorillonite-water-ion system have tended to focus on montmorillonite systems with different compensating cations, whereas natural montmorillonite mineral layers ...
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Chapter 12.10 Cation and Anion Exchange
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 …
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Montmorillonite
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 …
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Montmorillonite | Clay Mineral, Soil Conditioner, Adsorbent
montmorillonite, any of a group of clay minerals and their chemical varieties that swell in water and possess high cation-exchange capacities. The theoretical formula for montmorillonite (i.e., without structural substitutions) is (OH) 4 Si 8 Al 4 O 20 ·nH 2 O. The montmorillonite minerals are products of volcanism and hydrothermal activity and are …
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Montmorillonite: An Introduction to Properties and Utilization
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. …
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Smectite
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].
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Cations and Cation Exchange Capacity
Cations and Cation Exchange Capacity Key Points. Cation exchange capacity (CEC) is the total capacity of a soil to hold exchangeable cations.CEC is an inherent soil characteristic and is difficult to alter significantly.; It influences the soil's ability to hold onto essential nutrients and provides a buffer against soil acidification.
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Montmorillonite
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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Layer Charge-Cation-Exchange Capacity Relationships in Montmorillonite
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.
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Organoclays prepared from montmorillonites with different cation …
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 …
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Cation exchange interaction between antibiotic …
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 …
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The lower cation exchange capacity limit of montmorillonite …
The calculations of the cation exchange capacity CEC for the expanded interlayer part gives a constant value of 65 {+-} 2 mmol/100 g fully swellable montmorillonite. This value is denoted as the lower CEC limit of montmorillonite. The authors propose a model which considers montmorillonite to be a stacked two …
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Montmorillonite and modified montmorillonite as …
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].
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Cation Exchange
CATION EXCHANGE . Cation Exchange Capacity (CEC) Base Saturation . Soil Solution . Supply of Nutrients to Plant Roots. Nutrient Availability and Mobility ... but some soils contain significant amounts of montmorillonite, a clay mineral of the smectite group. CEC for various soils: a typical range of CEC for soils in the state and the region is ...
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Effect and mechanism of cation species on the gel …
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 …
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Cation exchange, interlayer spacing, and thermal analysis of …
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 …
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New Insights into the Molecular Structures, Compositions, …
We present a detailed investigation of the molecular structure of montmorillonite, an aluminosilicate clay with important applications in materials …
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Cation Exchange Capacity
Cation exchange capacity (CEC) is the ability of a soil surface to temporarily adsorb a nutrient and eventually release it back into the soil solution. ... This may explain why cation adsorption has not been consistently related to mineral bioavailability. However, wheat bran fibers can permanently bind heavy metal ions to decrease their ...
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Montmorillonite
Montmorillonite is a mineral with a permanent structural negative charge that requires external cations to balance. It plays a significant role in the migration and transformation of pollutants in photocatalytic degradation processes due to its exchangeable cations and unique structural properties. ... Cation-exchange capacity or solvation of ...
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Estimation of Cation Exchange Capacity of Montmorillonite …
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 …
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Inversion of Montmorillonite Ion-Exchange Characteristics
A natural layered aluminosilicate, montmorillonite, contains two groups of active sites, which give it the ability to adsorb both cations and anions [].Cation adsorption occurs by the ion-exchange mechanism via the replacement of interlayer alkali or alkaline-earth metal cations, which neutralize the negative charge of aluminosilicate layers, by …
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November 2011 Cation Exchange: A Review
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 other clays, such as montmorillonite or vermiculite, less than 10% of the CEC is affected by soil pH. The CEC of a soil is measured in how many positively charged ions ...
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November 2011 Cation Exchange: A Review
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 …
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Effects of cation exchange on the pore and surface structure …
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).
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ORGANO-MODIFICATION OF MONTMORILLONITE | Clays …
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 …
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Cation Exchange Capacity (CEC) of montmorillonite (the …
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 …
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HEAVY-METAL UPTAKE BY A HIGH CATION-EXCHANGE …
A High Cation Exchange Capacity (HCM) montmorillonite clay has been prepared by acetate treatment of Zenith clay. The HCM has been evaluated for metal-uptake from aqueous solutions. The present data show that the cation exchange sites can play a significant role in the adsorption of metals in smectite clays.
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