Swelling Of Montmorillonite Research Articles

Hydraulic conductivity of bentonite-polymer composite geosynthetic clay liners permeated with bauxite liquor

The high ionic strength of the porewater in red mud (bauxite liquor from digestion) can suppress swelling of montmorillonite, resulting in geosynthetic clay liners (GCLs) that are too permeable to be effective as liners in red mud disposal facilities. Bentonite-polymer composite GCLs (BPC GCLs) have been developed as more resilient lining materials, and some BPC GCLs have been shown to have very low hydraulic conductivity to bauxite liquors that have extreme ionic strength and pH. In this study, a nationwide investigation was conducted in China to evaluate the characteristics of bauxite liquor in Chinese impoundments, and to evaluate the suitability of GCLs containing granular sodium bentonite or BPCs for containment. Hydraulic conductivity tests were conducted on six BPC GCLs with two characteristic Chinese bauxite liquors that are hyperalkaline (pH > 12) and had ionic strengths of 76.9 mM and 620.3 mM. The BPC GCLs had hydraulic conductivity ranging from 10−8-10−12 m/s, which is higher than the hydraulic conductivity of BPC GCLs to deionized water (10−12-10−13 m/s), but lower than the hydraulic conductivity of conventional GCLs with granular sodium bentonite GCLs to the same liquors (10−7-10−8 m/s). The hydraulic conductivity of the BPC GCLs depends on the chemical properties of the leachate, the polymer loading, and the type of polymer. Microstructural analysis by scanning electron microscopy (SEM) suggests that the hydraulic conductivity of BPC GCLs is controlled by pore-blocking by polymer hydrogel, which is affected by the bauxite liquor.

Simple method for evaluating swelling of GMZ01 Na-bentonite affected by temperature at osmotic swelling

Swelling deformation tests of GaoMiaoZi (GMZ01) bentonite were performed at 25, 40 60, and 90 °C in distilled water. Experimental results suggested that the maximum swelling strain of GMZ01 bentonite increased with temperature, due to the osmotic swelling dominated the swelling. The em − σv relation for compacted bentonite at a same temperature can be expressed as em=KσvD-3 (em is montmorillonite void ratio, σv is vertical stress). The fractal dimension, D, of GMZ01 bentonite was unaffected by the temperature according to the results of N2 adsorption tests. Calculated by the diffuse double layer (DDL) model under the condition of osmotic swelling, a linearly relation was found between the montmorillonite swelling coefficient K and temperature Tc. Combing the fractal em − σv relation and linear K − Tc relation, a simple method for evaluating the swelling of GMZ01 bentonite affected by temperature was proposed.

Synergy of imidazolium ionic liquids and flexible anionic polymer for controlling facilely montmorillonite swelling in water

The hydration and swelling of clay minerals in the reservoir will probably bring about serious damage to stratum. Herein, a series of imidazolium ionic liquids (ILs) with different alkyl chains were synthesized to inhibit the swelling of montmorillonite (MMT). The relationship between the inhibitory property and ILs structure was determined through detailed studies. The combination of adsorption capacity, XPS and zeta potential demonstrated that ILs successfully adsorbed on MMT replacing Na+ ion. The adsorption behavior of ILs correlated well with Langmuir adsorption isotherm, implying the homogeneous monolayer adsorption. Besides, the presence of moderate amounts of flexible hydrolyzed polyacrylamide (HPAM) was favorable to improve the inhibition ability of ILs, where HPAM was adsorbed on the surface of MMT through ILs bridging, encapsulating the MMT particles. To understand inhibition mechanism in depth, the interlayer variation of dry and wet MMT and micromorphology of MMT particles were investigated to confirm the intercalation of ILs and stacking variation of MMT particles. Altogether, this study provides new insights into the structure-property relationships of imidazolium ILs and facilitates the design of excellent clay stabilizers.

Investigation on the inhibition mechanism of alkyl diammonium as montmorillonite swelling inhibitor: Experimental and molecular dynamics simulations

Effective inhibition of mud shale hydration and swelling is the major challenge for water-based drilling fluids (WBDFs). In this paper, a series of novel low molecular weight alkyl diammoniums with different alkyl chain lengths was synthesized and evaluated as montmorillonite swelling inhibitor. The inhibition behavior of alkyl diammonium was studied by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), cation exchange capacity (CEC), and molecular dynamics simulation. The XRD results illustrated that the inhibitors (Gs-9, Gs-10, Gs-11, Gs-12, Gs-13 and Gs-14) rapidly lowered the basal spacing (d001 value) of hydrated sodium montmorillonite (Na-Mt) from 1.92 nm to 1.41 nm, which indicates that a flat monolayer of inhibitors was inserted into the interlamination of Na-Mt. The XPS and CEC results showed that the alkyl diammonium displaced exchangeable cations in the interlamination of Na-Mt. The SEM results showed that the alkyl diammonium effectively improved the surface structure and curled edges of hydrated Na-Mt. The simulated results showed that the quaternary ammonium functional groups were fixed firmly on the six- oxygen rings of Na-Mt. The adsorption energy of alkyl diammonium increased with the increase in alkyl chain length. Therefore, alkyl diammonium with long alkyl chain can decrease the amount of inhibitor adsorbed on Na-Mt, thus reducing the dosage of inhibitor used in the WBDFs. This is conducive to reducing drilling costs. Therefore, this research on the inhibition behavior of alkyl diammonium with different hydrophobic chain lengths has important reference value for the development of WBDFs and suitable inhibitors for them.

Driving force for the swelling of montmorillonite as affected by surface charge and exchangeable cations: A molecular dynamic study

Abstract Swelling of montmorillonite (MMT) is a nonnegligible factor in many industrial processes owing to its great ability to absorb water in interlayer space. It is not easy to determine whether the exchangeable cations or the MMT layers interacts much stronger with water molecules to provide the dominant driving force for the swelling of MMT. In this work, driving force for the swelling of montmorillonite as affected by surface charge and exchangeable cations has been investigated through molecular dynamics simulations (MDs). The adsorption energy between water molecules and MMT layers and between interlayer cations and water molecules was calculated to qualitatively characterize the driving force for the swelling of MMT, and higher negative adsorption energy means greater driving force. It is found that the adsorption energy between interlayer cations and water molecules are far higher than that between MMT layers and water molecules. Thus, it is the exchangeable cations that provide the dominant driving force for MMT to swell. Besides, it is observed that interlayer cations with stronger hydration ability (Mg > Ca > Na > K) have more negative adsorption energy to water molecules, which indicates that the stronger the hydration ability of exchangeable cations the greater contribution they make to the total driving force for the swelling of MMT.

The Role of Clay Swelling and Mineral Neoformation in the Stabilization of High Plasticity Soils Treated with the Fly Ash- and Metakaolin-Based Geopolymers

In the southern U.S. states, expansive soils are frequently encountered, presenting an important hazard in geotechnical engineering. This research relies on mineralogical and geochemical clues to explain the swelling behavior of smectite-rich, high-plasticity soils, documented in a series of geomechanical swelling tests that were performed on the soils stabilized with the metakaolin (MKG) and fly ash (FAG) based geopolymers. These geopolymers were mixed with the soil at several concentration levels. The lowest swelling percentage was shown to correspond to the sample stabilized with 12% FAG and was attributed to the neoformation of calcium silicate hydrates that acted as a cementitious material, preventing the soil from expanding by occupying the pore space, thus binding the clay particles together. Conversely, the 12% MKG-stabilized soil exhibited enormous expansion, which was explained by montmorillonite swelling to the point that it gradually began to lose its structural periodicity. The relatively high abundance of the newly formed feldspathoids in MKG-treated samples is believed to have greatly contributed to the overall soil expansion. Finally, the cation exchange capacity tests showed that the percentage of Na+ and Ca2+, as well as the pH value, exercised strong control on the swelling behavior of smectitic soils.

Molecular Dynamics Study of Crystalline Swelling of Montmorillonite as Affected by Interlayer Cation Hydration

Swelling of montmorillonite (Mt) is an important factor for many industrial applications. In this study, crystalline swelling of alkali-metal- and alkaline-earth-metal-Mt has been studied through energy optimization and molecular dynamics simulations using the clay force field by Materials Studio 8.0. The delamination and exfoliation of Mt are primarily realized by crystalline swelling caused by the enhanced interlayer cation hydration. The initial position of the interlayer cations and water molecules is the dominated factor for the accuracy of the Mt simulations. Crystalline swelling can be carried out in alkali-metal-Mt and Mg-Mt but with difficulty in Ca-Mt, Sr-Mt and Ba-Mt. The crystalline swelling capacity values are in the order Na-Mt > K-Mt > Cs-Mt > Mg-Mt. This order of crystalline swelling of Mt in the same group can be attributed to the differences between the interlayer cation hydration strengths. In addition, the differences in the crystalline swelling between the alkali-metal-Mt and alkaline-earth-metal-Mt can be primarily attributed to the valence of the interlayer cations.

Synthesis and evaluation of a novel monomeric amine as sodium montmorillonite swelling inhibitor

A novel monomeric amine sodium montmorillonite swelling inhibitor: N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide was obtained from diethanolamine, 1-bromotetradecane, and 1, 2-dibromoethane. N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide was characterized by means of Fourier transform infrared, 1H NMR spectroscopy, elemental analysis, linear swelling tests, particle size distribution tests, X-ray diffraction, and thermogravimetric. Linear swelling tests showed that the swelling height of sodium montmorillonite in 1.0 wt% N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide solution was only 2.0 mm after 16 h (fresh water was 5.0 mm). Particle size distribution tests exhibited that the median diameter and mean particle size of sodium montmorillonite in 1.0 wt% N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide solution obviously increased to 16.1 and 85.4 µm, respectively (fresh water was 8.1 and 21.8 µm). In thermogravimetric tests, in comparison with pure sodium montmorillonite, the decrease of water content in sodium montmorillonite/ N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide indicated N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide expelled the water molecules out of the interlayer, which was beneficial to wellbore stability. Fourier transform infrared spectra of certain concentration N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide/sodium montmorillonite indicated the successful physical adsorption and interaction between N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide with sodium montmorillonite. In addition, the results of X-ray diffraction tests showed the obtained 1.0 wt% N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide solution could remarkably reduce the interlayer distance of wet sodium montmorillonite (from 1.94 to 1.37 nm).

Short- and Long-Range Attractive Forces That Influence the Structure of Montmorillonite Osmotic Hydrates.

Clay swelling is a colloidal phenomenon that has a large influence on flow and solute migration in soils and sediments. While models for clay swelling have been proposed over many years, debate remains as to the interaction forces that combine to produce the observed swelling behavior. Using cryogenic transmission electron microscopy (cryo-TEM) and small-angle X-ray scattering, we study the influence of salinity, in combination with layer charge, interlayer cation, and particle size, on montmorillonite swelling. We observe a decrease in swelling with increased layer charge, increased cation charge, and decreased cation hydration, each indicative of the critical influence of Coulombic attraction between the negatively charged layers and interlayer cations. Cryo-TEM images of individual montmorillonite particles also reveal that swelling is dependent upon the number of layers in a particle. Calculations of the van der Waals (vdW) interaction based on new measurements of Hamaker coefficients confirm that long-range vdW interactions extend beyond near-neighbor layer interactions and result in a decrease in layer spacing with a larger number of layers. This work clarifies the short- and long-range attractive interactions that govern clay structure and ultimately the stability and permeability of hydrated clays in the environment.

Effect of layer charge on the crystalline swelling of Na+, K+ and Ca2+ montmorillonites: DFT and molecular dynamics studies

AbstractThe swelling and cation exchange properties of montmorillonite are fundamental in a wide range of applications ranging from nanocomposites to catalytic cracking of hydrocarbons. The swelling results from several factors and, though widely studied, information on the effects of a single factor at a time is lacking. In this study, density functional theory (DFT) calculations were used to obtain atomic-level information on the swelling of montmorillonite. Molecular dynamics (MD) was used to investigate the swelling properties of montmorillonites with different layer charges and interlayer cationic compositions. Molecular dynamics calculations, with CLAYFF force field, consider three layer charges (−1.0, −0.66 and −0.5 e per unit cell) arising from octahedral substitutions and interlayer counterions of Na, K and Ca. The swelling curves obtained showed that smaller layer charge results in greater swelling but the type of the interlayer cation also has an effect. The DFT calculations were also seen to predict larger d values than MD. The formation of 1, 2 and 3 water molecular layers in the interlayer spaces was observed. Finally, the data from MD calculations were used to predict the selfdiffusion coefficients of interlayer water and cations in different montmorillonites and in general the coefficient increased with increasing water content and with decreasing layer charge.

Swelling Properties of Montmorillonite and Beidellite Clay Minerals from Molecular Simulation: Comparison of Temperature, Interlayer Cation, and Charge Location Effects

The swelling properties of smectite clay minerals are relevant to many engineering applications including environmental remediation, repository design for nuclear waste disposal, borehole stability in drilling operations, and additives for numerous industrial processes and commercial products. We used molecular dynamics and grand canonical Monte Carlo simulations to study the effects of layer charge location, interlayer cation, and temperature on intracrystalline swelling of montmorillonite and beidellite clay minerals. For a beidellite model with layer charge exclusively in the tetrahedral sheet, strong ion–surface interactions shift the onset of the two-layer hydrate to higher water contents. In contrast, for a montmorillonite model with layer charge exclusively in the octahedral sheet, weaker ion–surface interactions result in the formation of fully hydrated ions (two-layer hydrate) at much lower water contents. Clay hydration enthalpies and interlayer atomic density profiles are consistent with the sw...

Synthesis and Evaluation of Carboxymethyl Glucoside as Montmorillonite Swelling Inhibitor

Methylglucoside (MEG) has been used in the water-based mud with fine montmorillonite (MMT) swelling inhibition, but it still has such shortages as large concentration and low thermostability. In this work, carboxymethyl glucoside (CMG) was synthesized with glucose and sodium chloroacetate and used as swelling inhibitor. The inhibition of CMG against clay swelling was investigated by MMT linear expansion test, mud ball immersing test and bentonite inhibition test. The results showed that the CMG has a good inhibition to the hydration swelling and dispersion of MMT. Under lower concentrations, the linear expansion rate of MMT in CMG solution is much lower than that of MEG, and the hydration expansion degree of the mud ball in the CMG solution was significantly inhibited. The characterizations of physicalchemical properties of particle, analysized by thermogravimetric analysis and scanning electron microscopy revealed that CMG plays a great role in preventing water from absorbing and keeps MMT in large particle size.

Inhibitive effect of potassium methylsiliconate on hydration swelling of montmorillonite

Herein we report on a study on the inhibition effect of potassium methylsiliconate on hydration swelling of montmorillonite. The results of linear swelling tests showed that potassium methylsiliconate exhibits a high performance as an effective shale inhibitor in drilling fluids. The inhibition mechanism was investigated by means of a variety of methods including Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and zeta potential measurements. The high degree of inhibition is a result of the synergy of action of potassium cations and methylsiliconate anions. Methylsiliconate anions form a hydrophobic shell around each montmorillonite particle through the adsorption on the edge sites, thus inhibiting the penetration of water into the interlayer. The potassium ions promote the formation of a less hydratable structure of montmorillonite through cation-exchange interaction.

分子間力を考慮したモンモリロナイトの膨潤モデルの構築

本研究では陽イオンによるモンモリロナイト（Mo）の膨潤モデルの構築を行った。Moの体積変化は（1）Moの基本構造の単位層の集合体であるTactoid（Ta）の膨潤による体積変化と、（2）Taが形成する粗大構造の膨潤による体積変化の総和と考えた。前者は2平板の分子間力を考慮したモデルより算出し、後者の粗大構造の変化は実測した体積変化とTaの膨張による体積変化の差から算出した。粗大構造中の溶液とTa中の単位層間の溶液は一様であると考え、その化学ポテンシャルを2平板間の分子間力により決定した。その結果、粗大構造と化学ポテンシャルにはイオン種によらず関係性が見られ、化学ポテンシャルに基づくMoの膨潤予測モデルの構築ができた。

Synthesis of a Biglucoside and Its Application as Montmorillonite Hydration Inhibitor

A biglucoside (BG) was synthesized with glucose and epichlorohydrin as raw materials. The inhibition of BG against montmorillonite swelling was investigated by various methods including montmorillonite linear expansion test, mud ball immersing test, thermogravimetric analysis, and scanning electron microscopy. The results show that the BG has good inhibition ability to the hydration swelling and dispersion of montmorillonite. Under the same condition, the linear expansion ratio of montmorillonite in BG solution is much lower than that of MEG. The particle distribution measurement, thermogravimetric analysis, FT-IR, and scanning electron microscopy results all prove the efficient inhibition of BG.

Inhibitive Effect of Potassium Methylsiliconate on Hydration Swelling of Montmorillonite

Inhibitive Effect of Potassium Methylsiliconate on Hydration Swelling of Montmorillonite

Effect of silica nanoparticles on clay swelling and aqueous stability of nanoparticle dispersions

The results of the effects of electrolyte type and concentration, nanoparticle concentration, pH, and temperature on the mobility and aqueous stability of polyethylene glycol (PEG)-coated silica nanoparticles are presented. Nanoparticle mobility was evaluated based on the ability to inhibit montmorillonite swelling in aqueous solutions through visual swelling tests, and the results were quantified in terms of the swelling index. The presence of PEG-coated silica nanoparticles was found to have a positive influence on the inhibition of clay swelling only in the presence of electrolytes. Quantification of nanoparticle stability in the presence of montmorillonite particles was achieved using ultraviolet–visible (UV–vis) spectrophotometry. At the highest concentration of montmorillonite dispersion studied, interaction between the dispersed montmorillonite particles and PEG-coated silica nanoparticles resulted in nanoparticle aggregation as indicated by increased turbidity and absorbance readings. Both nanoparticle concentration and montmorillonite dispersion concentration, in addition to the presence and concentration of NaCl, were found to strongly influence the stability of the mixture.

Inhibiting effect of dopamine adsorption and polymerization on hydrated swelling of montmorillonite

This paper aims at evaluating the inhibition performance of dopamine (DA) on hydrated swelling of montmorillonite (MMT) and exploring the inhibitive mechanism. The inhibition performance of DA was evaluated through the combination of linear swelling and mud making tests, and compared with three commonly used inhibitors in the field. The results show that DA performs extremely well on inhibiting the MMT swelling, within a broad temperature range even at 200°C. Based on a combined use of FT-IR, XPS, XRD, zeta potential and TEM analysis, the probable inhibition mechanism was determined due to the identification of the structure of polydopamine (pDA) polymerized in the MMT interlayer. The results indicate that the forming of interlayered pDA that composed of bilayer planer 5, 6-dihydroxyindole (DHI) oligomers is primarily responsible for the excellent inhibition ability of DA. In addition to this, the collapse of MMT colloidal particle diffuse double layers due to the adsorption of positive charged DA monomers also contributed considerably to the inhibition effect on hydrated swelling.

In situ X-ray Diffraction Study of the Swelling of Montmorillonite as Affected by Exchangeable Cations and Temperature

AbstractThe swelling property of smectite is dominated by the hydration of exchangeable cations in the interlayer spacing (‘interlayer hydration’). By investigating systematically the swelling behavior of various exchangeable cations with different valences and ionic radii, the interlayer hydration of smectite was explored. The swelling behavior of Li+-, K+-, Rb+-, Cs+-, Mg2+-, Sr2+-, Ba2+-, and La3+- montmorillonites in undersaturated conditions was measured precisely over the range 50–150°C by in situ X-ray diffraction (XRD) analyses. The systematic swelling behavior of ten homocationic montmorillonites, the aforementioned eight homoionic montmorillonites, plus Na+ and Ca2+ from a previous study, and the cation hydration energies were analysed by studying the changes occurring in the basal spacing and the 001 peak width. With decreasing cation hydration energy, swelling curves (i.e. plots of basal spacing vs. relative humidity (RH)) change from continuous (Mg2+, La3+, and Ca2+) to stepwise (Sr2+, Li+, Ba2+, and Na+) to one-layer only (K+, Rb+, and Cs+). For the first two groups, the RH at the midpoint between the one- and two-layer hydration states increased as the cation hydration energy decreased. Under low RH, with increasing temperature, the basal spacings of Mg-, La-, Ca-, Sr-, Li-, and Ba-montmorillonites decreased continuously to the zero-layer hydration state, whereas Na-, K-, Rb-, and Cs-montmorillonites swelled from the zero-layer hydration state even at the lowest temperature (50°C). A decrease in the basal spacing at the same RH but at different temperatures suggests the existence of metastable states or that the layer-stacking structure changes with temperature. The systematics of the swelling behavior of various homocationic montmorillonites as functions of RH and temperature (<150°C) at 1 atmare reported here.

Swelling of K+, Na+ and Ca2+-montmorillonites and hydration of interlayer cations: a molecular dynamics simulation

This paper performs molecular dynamics simulations to investigate the role of the monovalent cations K, Na and the divalent cation Ca on the stability and swelling of montmorillonite. The recently developed CLAYFF force field is used to predict the basal spacing as a function of the water content in the interlayer. The simulations reproduced the swelling pattern of these montmorillonites, suggesting a mechanism of their hydration different (K+ < Na+ < Ca2+) from that of K+-, Na+-, and Ca2+-montmorillonites. In particular, these results indicate that the valence of the cations has the larger impact on the behaviour of clay-water systems. It also finds that the differences in size and hydration energy of K+, Na+ and Ca2+ ions have strong implications for the structure of interlayer. This leads to the differences in the layer spacings of the simulated K+-, Na+-, and Ca2+-montmorillonites. Furthermore, these simulations show that the K cations interact strongly with the clay sheets for the dehydrated clay sheets, but for the hydrated clays the Ca cations interact clearly strongly with the clay sheets.