MMT Clay Research Articles

Nanoencapsulation of montmorillonite clay within poly(ethylene glycol) nanobeads by electrospraying

ABSTRACTThe present study describes the preparation and characterization of a novel nanocomposite, based on montmorillonite clay (MMT) encapsulation in poly(ethylene glycol) (PEG) by an electrospraying process. PEG/MMT nanocomposites with MMT contents ranging from 1 to 5 wt % were successfully prepared and characterized in relation to their morphological, spectroscopic, structural, and thermal properties. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy micrographs showed that the PEG nanobeads formed spherical shapes, and with increasing amount of MMT clay, the size of the beads decreased significantly, ranging from 120 to 3.7 nm. The Fourier transform infrared spectroscopy results suggested that there was no significant chemical interaction between PEG and MMT clay. However, the d‐spacing of MMT clay in PEG/MMT increased, a clear indication of the intercalation of PEG in the interlayer spaces of MMT clay. Furthermore, the thermal stability of PEG polymer decreased upon encapsulation of MMT clay in PEG/MMT composites. Nanoindentation results showed that the hardness and Young's modulus of the PEG/MMT composites increased with 3 wt % loading of MMT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45048.

Effect of nanoclay addition on physical, chemical, optical and biological properties of experimental dental resin composites

ObjectiveTo prepare organically modified montmorillonite (OM MMT) and assess mechanical, physical, chemical and biological effects of its introduction into resin-composites. MethodsNatural MMT clay was modified by a methacrylate functionalized quaternary ammonium intercalating agent. Interlayer distance was measured by X-ray diffraction. Dental composites were then prepared with x=0, 1, 2.5, 5 or 7.5wt.% of OM MMT, (75−x) wt.% of silanated barium glass and 25wt.% of methacrylate based matrix). Relative weight loss was measured and the effect of the substitution on mechanical properties was studied by dynamic mechanical analysis and hardness tests. Properties of resin composites were evaluated in terms of water sorption, light transmittance, biological tests and by high-performance liquid chromatography (HPLC). ResultsResin based composites with well-dispersed organically modified MMT were successfully prepared. There were no significant weight loss differences shown by TGA within all samples. The DMA analysis showed that the introduction of clays have a beneficial effect in increasing the storage and elastic modulus of composites. Clay presence was shown to interfere with the blue light transmittance, affecting Vickers hardness and water sorption levels. The amount of released monomers measured from extracts was below expected levels for this type of materials and biological tests show satisfactory cell compatibility. SignificanceThis paper reports the successful functionalization of MMT by a methacrylate group and further incorporation in experimental dental composites. Physical and biological results show a potential interest to the application of nanoclays into dental resin composites.

Comparative Effects of MMT Clay Modified with Two Different Cationic Surfactants on the Thermal and Rheological Properties of Polypropylene Nanocomposites

Polypropylene montmorillonite (MMT) nanocomposites were prepared by melt blending using two different organoclays modified with imidazolium and alkylammonium surfactants. The imidazolium and ammonium modified organoclays were characterized by the FTIR and SEM analysis. The effect of organic clay (MMT) on the physical properties of polypropylene was evaluated, thermal and rheological properties with different filler weight percentage. Differential scanning calorimetric results showed that imidazolium modified clay (IMMT) exhibits low melting temperature compared to the ammonium modified clay (AMMT). The crystallinity analysis showed that crystallization improved in all nanocomposites irrespective of surface modification; the thermogravimetric analysis showed that the imidazolium modified polymer composites are more thermally stable than conventional ammonium modified composites. The Transmission Electron Microscopy (TEM) analyses indicated that the PP-IMMT composites displayed exfoliated morphologies compared with the intercalated structure in PP-AMMT, and the rheological analysis at 180°C showed an enhancement in the viscoelastic properties as the clay concentration increases. The melt viscosity, crossover modulus, and relaxation times were comparable for both the surface modified composites with two different cations. The imidazolium based surfactant was found to be an effective organic modification for MMT to prepare thermally stable PP/MMT nanocomposites.

Role of silane concentration on the structural characteristics and properties of epoxy-/silane-modified montmorillonite clay nanocomposites

In the present work, sodium montmorillonite (MMT) was modified with varying concentrations of (3-amino propyl) triethoxy silane (APS) using water as the dispersing medium. Successful grafting of APS was corroborated using Fourier transform infrared spectroscopy (FT-IR). X-ray diffraction (XRD) studies of silane-modified clay revealed that the average d-spacing values increase at low silane concentration with the almost constant values at higher silane concentration. Total grafting yield of APS calculated using differential thermogravimetric results revealed that grafting yield decreases with increasing silane concentration. Epoxy-based MMT clay nanocomposites were prepared with different loading amounts of pristine (PM0.0) and silylated clay (SM4.4), and its influence on the mechanical, dynamic mechanical, and water uptake properties of the nanocomposites was investigated. The degree of intercalation of pristine or modified clay in the epoxy matrix estimated by XRD experiments exhibits a clear diffraction peak corresponding to the interlayer spacing d001 of 14.8–28 Å. Characterizations of mechanical properties revealed that Young’s modulus and tensile strength increase with increasing concentration of the modified clay, while the fracture toughness shows a maximum at 6 wt% of clay. From the results of dynamic mechanical analysis, it was observed that the nanocomposites filled with silylated clay display higher storage modulus mainly at temperatures above the glass transition temperature. The equilibrium water uptake was reduced significantly on loading 6 wt% of pristine MMT, and this effect is more pronounced on loading silanized MMT in the nanocomposites when compared to the neat epoxy system.

Probing electronic structure of biomineralized hydroxyapatite inside nanoclay galleries

Hydroxyapatite, the most abundant mineral in the human body, is also an important component in design of biomaterials for bone tissue regeneration. Synthetic hydroxyapatite mineralized in the laboratory often does not exhibit the same biological and morphological properties of biogenic hydroxyapatite in human bone. A biomimetic hydroxyapatite structure is synthesized using biomineralization routes inside the clay galleries of montmorillonite clay. Amino acids are used to modify the clay galleries. These amino acids are used to mineralize hydroxyapatite. The molecular interactions between nanoclay, modifiers inside nanoclay (amino acids) and biomineralized hydroxyapatite result in unique morphology, structure and stoichiometry of the biomineralized hydroxyapatite. Prior studies have indicated that this biomineralized hydroxyapatite inside nanoclay galleries is an effective component of tissue engineering bone scaffolds that elicits an optimal biological response from human mesenchymal stem cells. Here, a detailed electron energy-loss spectroscopy (EELS) study is reported that elucidates the differences in hydroxyapatite, biomineralized hydroxyapatite and β-tricalcium phosphate (β-TCP). Comparison of EELS low-loss transitions and energy loss near-edge structure (ELNES) of P-L2,3 edges for these three compounds is done to determine if there are differences in their electronic structures. These changes observed experimentally are compared with prior predictions and simulations using molecular dynamics studies. The simulations predict attractive and repulsive interactions between phosphate, modified MMT clay and aminovaleric acid (amino acid) molecules. Kramers-Kronig analysis is performed on the loss spectra obtained to yield the real and imaginary parts of the dielectric function of the apatites (ε1 and ε 2). We have also used the ε2 spectra obtained to calculate the AC conductivity spectra for the apatites. This study represents a unique experimental probe into molecular interactions in complex biomineralized hydroxyapatite structures. The small changes observed in the energy loss spectra appear to play important biological roles in biomineralized hydroxyapatite such as the ability to differentiate human mesenchymal stem cells into osteoblasts without growth media.

Preparation and Characterization of Polymer-Grafted Montmorillonite-Lignocellulose Nanocomposites by In Situ Intercalative Polymerization

Lignocellulose-clay nanocomposites were synthesized using an in situ intercalative polymerization method at 60°C and a pressure of 1 atm. The ratio of the montmorillonite clay to the lignocellulose ranged from 1 : 9 to 1 : 1 (MMT clay to lignocelluloses, wt%). The adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). FTIR results showed that the polymers were covalently attached to the nanoclay and the lignocellulose in the nanocomposites. Both TEM and XRD analysis showed that the morphology of the materials ranged from phase-separated to intercalated nanocomposite adsorbents. Improved thermal stability, attributable to the presence of nanoclay, was observed for all the nanocomposites. The nanocomposite materials prepared can potentially be used as adsorbents for the removal of pollutants in water treatment and purification.

Elaboration and behavior of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)- nano-biocomposites based on montmorillonite or sepiolite nanoclays

Poly(3hydroxybutyrate-co-4hydroxybutyrate) (P(3HB-co-4HB)) is a polyhydroxyalkanoate (PHA), which is known for its properties and performance leading to a wide range of applications. Compared to more conventional PHAs such as P(3HB) or P(3HB-4HV), P(3HB-co-4HB) is known for its mechanical properties. P(3HB-co-4HB) has the potential to replace some fossil-based thermoplastics in certain fields. However, it is thermally sensitive like most PHAs and this puts limitations on its potential as an important biobased and biodegradable polymer. The present work is based on the study of multiphase systems of P(3HB-co-4HB) elaborated to prepare nano-biocomposites using two nanoclays, montmorillonite (MMT) and sepiolite (Sep). The clays differ in geometries with MMT having sheet structure and Sep having fiber structure. The environment-friendly non-solvent based elaboration of P(3HB-co-4HB) in the presence of nanoclays allows for minimizing thermal degradation while improving the overall mechanical properties and thermal resistance of the final multiphase materials. The degree of improvement in the properties is found to be not only a function of the clay dispersion in the polymer matrix but also on the morphology/shape of the clay particles and interfacial polymer-clay interactions. It has been found that despite the higher aspect ratio of lamellar-type MMT clays, the fiber-like Sep clay has better stiffening properties arising mainly from the better polymer-clay interactions through the silanol groups along the length of the fiber. As a result of this increased “effective” aspect ratio of Sep, the properties of the Sep-based nano-biocomposites are greatly enhanced. The detailed analyses using various techniques (TGA, DSC, TEM, XRD, uniaxial tensile test) allows comparison and analysis of the structure-property relationships between MMT and Sep nano-biocomposites.

Novel Polymer Clay‐Based Nanocomposites: Films with Remarkable Optical and Water Vapor Barrier Properties

The impact of varying the copolymer composition of styrene–co‐butyl acrylate copolymers on the dispersion of montmorillonite (MMT) clay and the effect thereof on the transparency and water vapor barrier properties of the resultant films is assessed. The hybrid latexes containing MMT clay concentrations of 10–30 wt% are prepared using miniemulsion polymerization. The morphology of the resultant latexes shows that the MMT particles are predominantly adhered onto the surface of the latex particles. However, the transparency of the films suggests a fair dispersion of the MMT platelets in the matrix. The thickness‐normalized light transmittance for copolymers with 40 and 50 mol% styrene only decreases from 70% in the neat films to 50% in the nanocomposite films containing 30 wt% clay. The best optical properties are observed for the copolymers with 30 mol% styrene, in which the light transmittance only decreases from 85% (unfilled film) to 60% in the nanocomposite films containing 30 wt% clay. Overall, the water vapor barrier properties are much higher in the copolymer films with 30 mol% styrene due to the unique morphological organization of MMT platelets in the matrix. image

Microwave‐crosslinked bio‐based starch/clay aerogels

AbstractFoam‐like robust starch/sodium montmorillonite (Na+‐MMT) aerogels were fabricated through a freeze‐drying process. Glutaraldehyde (GL) was used to crosslink the starch aerogels with the assistance of radiation supplied by a domestic microwave oven. The chemical reaction between GL and starch was analysed using Fourier transform infrared spectroscopy and water swelling tests. The microstructures and mechanical properties of the resultant crosslinked starch aerogels changed with GL concentration. By incorporating 5% (w/w) GL, the specific compressive modulus and absorbed energy increased by 2.4 and 3.3 times, respectively. In regard to starch/clay aerogel composites, Na+‐MMT clay played the role of reinforcement. Moreover, clay addition created more porous structures and hence decreased the thermal conductivity of the aerogels. The biodegradability of the aerogels was studied using a homemade micro‐respirometer. The starch aerogels exhibited higher biodegradability than poly(vinyl alcohol)‐based ones and their corresponding films. © 2016 Society of Chemical Industry

The effects of material formulation and manufacturing process on mechanical and thermal properties of epoxy/clay nanocomposites

A holistic study was conducted to investigate the combined effect of three different pre-mixing processes, namely mechanical mixing, ultrasonication and centrifugation, on mechanical and thermal properties of epoxy/clay nanocomposites reinforced with different platelet-like montmorillonite (MMT) clays (Cloisite Na+, Cloisite 10A, Cloisite 15 or Cloisite 93A) at clay contents of 3–10 wt%. Furthermore, the effect of combined pre-mixing processes and material formulation on clay dispersion and corresponding material properties of resulting composites was investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), flexural and Charpy impact tests, Rockwell hardness tests and differential scanning calorimetry (DSC). A high level of clay agglomeration and partially intercalated/exfoliated clay structures were observed regardless of clay type and content. Epoxy/clay nanocomposites demonstrate an overall noticeable improvement of up to 10 % in the glass transition temperature (T g) compared to that of neat epoxy, which is interpreted by the inclusion of MMT clays acting as rigid fillers to restrict the chain mobility of epoxy matrices. The impact strength of epoxy/clay nanocomposites was also found to increase by up to 24 % with the addition of 3 wt% Cloisite Na+ clays. However, their flexural strength and hardness diminished when compared to those of neat epoxy, arising from several effects including clay agglomeration, widely distributed microvoids and microcracks as well as weak interfacial bonding between clay particles and epoxy matrices, as confirmed from TEM and SEM results. Overall, it is suggested that an improved technique should be used for the combination of pre-mixing processes in order to achieve the optimal manufacturing condition of uniform clay dispersion and minimal void contents.

Molecular Simulation of Shale Gas Adsorption and Diffusion in Clay Nanopores

The present work aims to study the adsorption behavior and dynamical properties of CH4 in clay slit pore with or without cation exchange structures at sizes of 1.0 nm–4.0 nm using grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) methods. The adsorption isotherms of CH4 have been investigated by GCMC simulations at different temperatures and various pore sizes. In the montmorillonite (MMT) clays without a cation exchange structure, from the density profile, we find the molecules preferentially adsorb onto the surface, and only an obvious single layer was observed. The general trend within slit pores is that with increasing pore width, the adsorbed amount will increase. However, the larger pores exhibit lower excess density and the smaller pores exhibit higher excess density. The preloaded water will reduce CH4 sorption. The in plane self-diffusion coefficient of CH4 which is investigated by MD simulations combined with Einstein fluid equation increases rapidly with the pore size increasing at low pressure. Under these given conditions, the effect of temperature has little influence on the in-plane self-diffusion coefficient. In the MMT clays with cation exchange structure, cation exchange has little effect on CH4 adsorption and self-diffusion.

Poly (Lactic Acid)/MMT Nanoclay Hybrid Nanocomposites : Mechanical and Thermal Properties

Poly (lactic acid)/clay nanocomposites were prepared by solution-casting and melt-blending techniques, and their morphologies and mechanical properties were studied. In morphology studies revealed an intercalated–exfoliated mixed structure for the nanocomposites obtained by both techniques. SEM images show a good clay dispersion degree. Sodium lauryl sulphate (SLS here after called) is used to modify the MMT Clay to improve the surface characteristic of the clay. The mechanical properties of nanocomposites from the melt-blending technique were superior to those obtained by solution-casting method. In both cases, the highest elongation at break and Young’s modulus were achieved at 5wt% SLS-montmorillonite SLS-MMT content.

The influence of processing techniques on the matrix distribution and filtration of clay in a fibre reinforced nanocomposite

A nano-modified matrix based on an epoxy resin and montmorillonite (MMT) layered silicates, was successfully infiltrated through 10 ply of carbon fibre preform. A combined fabrication process of a vacuum assisted resin infusion method (VARIM) followed by a rapid heating rate and mechanical vibration during cure, facilitated the infiltration of the nano-modified matrix through the preform. This was achieved by dispersing the MMT clay in the resin and ensuring that the viscosity of the nano-modified matrix remained low during fabrication. SEM-EDX (energy dispersive X-ray spectroscopy) spectra showed that chemical constituents within MMT clay including silicon, aluminium and magnesium elements had permeated through the fibre preform and were detected throughout the laminate. A homogeneous resin/particle distribution was achieved with the size of clay particles ranging from 100 nm to 1 μm.

An exfoliated clay-poly(norbornene) nanocomposite prepared by metal-mediated surface-initiated polymerization

An exfoliated clay−polymer nanocomposite was prepared by surface-initiated ring opening metathesis polymerization (SI-ROMP) of norbornene on a montmorillonite (MMT) clay with a modified surface. Utilizing the hydrothermal-silylation reaction between a norbornenyl-bearing chlorosilane agent and silanol groups of the MMT clay, we were able to bind a metal alkylidene catalyst to the surface in order to grow poly(norbornene) chains directly from the surface using ROMP. Our approach produced nanocomposites having poly(norbornene) chains that are covalently attached to the inorganic substrate, as opposed to most conventional polymer-clay composites that have ionically tethered chains (via the ammonium-based modifiers of the organoclay) or physically adsorbed polymers. POLYM. ENG. SCI., 55:2349–2354, 2015. © 2015 Society of Plastics Engineers

Estudo da incorporação de argilas montmorilonitas em cimentos asfálticos de petróleo

A utilização de nanotecnologia em pavimentos asfálticos é uma revolução, pois esta permite construir pavimentos mais resistentes à deformação, à trinca por fadiga, à trinca por temperatura e à ação da água.Nesse contexto uma alternativa é o uso da nanoargila. Sua incorporação ao cimento asfáltico de petróleo (CAP) proporciona melhoria nas propriedades físicas e reológicas e nas propriedades mecânicas das misturas asfálticas. Para o desenvolvimento deste trabalho utilizou-se o método da dosagem SUPERPAVE para a análise do comportamento das misturas asfálticas utilizando o CAP 50/70 modificado com as seguintes adições: Argila Montmorilonita organofílica (OMMT) e a Argila Montmorilonita pura (MMT). Foram analisados os efeitos dos modificadores por meio de ensaios mecânicos de Resistência à Tração por Compressão Diametral e Módulo de Resiliência, sendo todas as amostras submetidas ao processo de compactação por amassamento. Os resultados indicaram que as adições das argilas OMMT e MMT as misturas asfálticas promoveram aumento no valor do Módulo de Resiliência e da Resistência à Tração quando comparados ao ligante asfáltico sem modificador.

Tuning of Final Performances of Soybean Oil–Based Polymer Nanocomposites: Effect of Styryl/Oil Functionalized Intercalant of Montmorillonite Reinforcer

Abstract Bio-based polymeric nanocomposites were prepared via polymerization of a monomer mixture of acrylated epoxidized soybean oil (AESO) and styrene in the presence of organophilic montmorillonite (MMT) clay by in-situ free-radical polymerization technique. MMT clay was rendered organophilic by a styryl/oil functionalized intercalant which is compatible with the two matrices and able to participate in the polymerization/crosslinking reaction. The presence of styryl group in the intercalant is also thought to be an original solution to the drawback mentioned in the literature arising from higher amount of small styrene monomer molecules in the clay galleries than larger AESO molecules at high clay loadings. The current design of the interclant is expected to allow polymer molecules grown from both AESO and styrene monomers inside the clay galleries and also from edges/surfaces of the silicate layers. In this study, a special attention was paid to the enhancement of both thermal and mechanical properites of AESO-based nanocomposites via usage of the compatible and reactive intercalant for MMT modification. The resultant nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of increased nanoclay loading in thermal and mechanical properties was investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The nanocomposite materials exhibited improved thermal stability and dynamic mechanical properties as compared to neat polymer. The nanocomposite with exfoliation dominant structural morphology showed the highest storage modulus around Tg which is about 480% higher than that of neat AESOPS, even with a clay content as low as 3 wt%.

A study of the erosive wear damage on a recycled polymer coating

In this work, erosion tests were carried out to study the wear damage on a coating made of a recycled polymeric matrix (crystal polystyrene) and clay (montmorillonite (MMT)). The latter was modified and purified with bromide quaternary salts (hexadecyltrimethyl ammonium bromide). The coating preparation was by liquid via dissolving 25% crystal polystyrene in a solution of 70% ethyl acetate and 30% acetone, after this, 1wt% of modified MMT clay was added. The clay/polystyrene matrix coating was applied by immersing wood substrates in the liquid phase of the mixture. This process was repeated five times to get the final coating layer on the substrates. An erosion rig similar to that in ASTM G76-95 was used to perform the tests. The abrasive particle used to conduct the erosion tests was glass beads with a particle size between 200 and 240µm. The impact angles were 30°, 45°, 60° and 90° with a velocity of 2.5±0.5m/s. The abrasive flow rate was 5.5±0.5g/min. The room temperature was between 35°C and 40°C. The results showed that the coating presented its maximum erosion rate at 45°. In addition, the erosion rates were decreased in the clay–polystyrene coating compared to those observed in the uncoated specimens at all incident angles. The wear mechanisms identified in SEM images were consistent pitting action, radial cracks and deposition of particle fragments on the coating surfaces.

The Influence of Water in Montmorillonite Clay on the Performance As Electrode Material for Li-Ion Battery/Capacitor

Recently, 2D materials have attracted great attention as electrode materials for lithium ion batteries due to their special electochemical properties. Clays are nature abundant materials which have 2D layered structures. Montmorillonite (MMT) is one of them and composed of units made up of two silica tetrahedral sheets with a central alumina octahedral sheet. The cation and water content in inter layer varies with source. Unlike graphene related materials, electrochemical properties of MMT has rarely been studied. Our recent research shows that MMT could be used as a green electrode material for Li-ion battery/capacitor. Here in this study, we will exam the influence of water in MMT clay on the electrochemical performance. The performance of various status of MMT, in nature or dehydrated, will be exam. Conductive agent will also be added to improve conductivity of MMT electrode. Both traditional slurry casting and electrostatic spray deposition (ESD) will be used to fabricate the electrode. Fig. 1(a) shows the TEM image of nature MMT clay and (b) cyclic voltammetry (CV) curves of slurry casting MMT electrode. More detailed results will be shown during the meeting. Figure 1

Solid particle erosion of a coating composed of clay in a polystyrene matrix

In this work, erosion tests were carried out to study the wear resistance of a coating made of montmorillonite-MMT clay in a crystal polystyrene-PS matrix. The MMT clay was modified and purified with bromide quaternary salts (hexadecyltrimethyl ammonium chloride). The coating preparation was by liquid via dissolving 25% crystal polystyrene in a solution of 70% ethyl acetate and 30% acetone, after this, modified montmorillonite was added and the coating application was by immersion of the substrate (AISI 6061 aluminium) in the liquid phase polymer coating. The substrates were coated with five layers of coating and the percentage of montmorillonite varied between 0.7–1.5wt%. An erosion rig similar to that shown in ASTM G76-95 was used to perform the tests. The glass bead particles had a particle size between 200–240µm. Tests were carried out using impact angles, 30°, 45°, 60° and 90° with a velocity of 2.5±0.5m/s. The abrasive flow rate was 5.0±0.5g/s. The room temperature was between 35°C and 40°C. Chemical compositions of the particles, substrate and the coating were obtained using energy dispersive X-ray analysis (EDS). In addition, SEM images were used to identify the wear mechanisms. Finally, AFM was used to obtain the 3D roughness profiles of the coating surface before tests.

First principles characterization of silicate sites in clay surfaces.

Aluminosilicate clays like Montmorillonite (MMT) and Muscovite Mica (MT) have siloxane cavities on the basal plane. The hydroxyl groups localized in these cavities and van der Waals (vdW) forces contribute significantly to adsorption processes. However, the basal sites are found to be difficult to characterize experimentally. Here, (001) surfaces of MMT and MT clays were investigated using first-principles calculations to understand how these silicate surface sites are influenced by hydroxyl groups and the effective role of inner layer vdW interactions. Based on density-functional theory (DFT) within the generalized gradient approximation (GGA), different types of exchange-correlation functionals were tested to check the effect of vdW dispersion correction. Noncontact atomic force microscopy (nc-AFM), X-ray absorption spectroscopy (XAS) in the near-edge region and solid-state nuclear magnetic resonance (SS-NMR) spectroscopy were simulated. In both clays, the oxygen surface sites are directly affected by the intralayer interaction through hydroxyl groups. Our results indicated that the chemical environment of the hydroxyl groups is distinct in the MMT and MT structures. The vdW correction was essential for a better description of the surface oxygen sites and correctly describes the similarity between both clays. Particularly, the bulk apical oxygen sites in the MT structure are less influenced by vdW interaction. Compared to MMT, the silicon surface sites of MT are more sensitive to the intralayer changes in Si-Oapical-Al and with less effect of the hydroxyl groups. These results provide a clear understanding of influence of the siloxane cavity on the oxygen and silicon surface sites in aluminosilicates.