Montmorillonite Research Articles

Preparation of a Carbon paste electrode with Active materials for the detection of Tetracycline

The Electrochemical sensor based on carbon-clay paste electrode (CCPE) was constructed for sensitive determination of Tetracycline (Tc). The mineralogical composition, morphology, structure and performance of CCPE were characterized using X-ray diffraction powder, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Cyclic Voltammetry analysis. The CCPE is constituted of two types of clay having the ratio 1/1 and 2/1 characteristic of kaolinite and montmorillonite clay respectively. Its porous structure is ascribed to the presence of graphite. The CCPE exhibited a good electrocatalytic activity towards the oxidation of Tc. The electrochemical kinetics and mechanism of Tc were proposed, showing that Tc electrocatalytic oxidation reaction was controlled by diffusion process and took place in three steps. A low concentration of Tc was detected by amperometry with the linear ranges of 0.5μM–0.8 μM (R2 = 0.98), the sensitivity was 8.01 μA/μM.cm2, the limit of detection and quantification were 5.16x10−3μM(S/N = 3) and 1.72x10−2μM respectively. Thus, the proposed electrode provides a promising and prospective CCPE sensing platform for the detection of Tc in the environment.

Effect of different nanofillers incorporation on HDPE/LDPE films nanocomposite

The objective of this study was to develop polymeric films of high-density polyethylene (HDPE)/low-density polyethylene (LDPE) that comprise 1 wt% of different nanofillers, that is, either nanofibrillated cellulose (NFC), montmorillonite clay (MMT), or graphene nanoplatelets (GNPs); the polymeric films were developed with and without the inclusion of a coupling agent (CA). The results indicated that all the samples that comprised nanofillers exhibited, at least, an increase of 3 to 25°C compared with that of the matrix and demonstrated higher stability at the beginning of the thermal degradation, as verified using TGA. In the DSC analysis of the samples that contained GNPs had highest crystallinity index (55%), having as the consequent improvement in the mechanical properties and in the oxygen permeation. The incorporation of GNPs provided a 127.71% increase in deformation at break and a lower value in oxygen permeability with 50.06 mL.cm.(cm2.s.cmHg)−1, when compared to the polymeric matrix. It was concluded that all the different nanofillers tested promoted distinct improvements in HDPE/LDPE films nanocomposite. It can be inferred that these modifications are related to the chemical composition, size and morphology of each nanofiller. Thereby, it is indicated that with the use of each nanofiller one must be in accordance with the necessary demand of each composite film.

Simultaneous Removal of Toxic Ammonia (NH3/NH4 +) from Aqueous Solutions Using New Geomaterial Adsorbent: Application to Aquaculture Effluents

This study evaluates the performance of a new geomaterial (GEOM) based on sodium montmorillonite clay (Na-Mt), local activated carbon (CAC) and fine powder local cement (Chlef plant western Algeria) to remove ammonia from fish farming in a recirculating aquaculture system. The aqueous ammonium (NH4 +/NH3) adsorption efficiency of GEOM was compared with its two principals` constituents (Na-Mt and CAC) and another commercial activated carbon (CAG). The results of X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to assess the chemical and physicochemical properties of studied adsorbents. The maximum adsorption capacity of NH4 + on GEOM of about 15.57 mg. g-1 seems to be similar to that of Na-Mt 16.82 mg. g-1. The study of solution pH showed that the best NH4 +/NH3 removal efficiency was at pH=6 for both GEOM and Na-Mt. The efficiency of GEOM for ammoniacal nitrogen (NH4 +/NH3) removal was 79.3% in ultrapure water, 94.05% in seawater and 97.5% in real aquaculture wastewater. Thus, the proposed material, GEOM, can be used as a filter material in a bio-filtration process to treat aquaculture wastewater in a real-world context.

Nanoclay protonation and silane functionalization to enhance mechanical and fracture performance of epoxy nanocomposites

AbstractNanoclay is considered to be one of the best fillers for reinforcement in structural polymer composites because of its low cost, easy availability, and ability to improve mechanical, thermal, corrosion resistance, barrier properties and nonflammability in corresponding nanocomposites. Pristine nanoclay is hydrophilic and therefore needs surface modification to make it compatible for uniform dispersion with polymer matrix. In the present work, montmorillonite nanoclay was protonated for generating more hydroxyl groups to facilitate silane functionalization and is reinforced to prepare epoxy nanocomposites with a varying content of 0.5 to 20 wt%. Studies are also conducted to investigate the effect of silanization of unprotonated nanoclay on epoxy nanocomposites. Interestingly, uniform highly exfoliated reduced‐size nanoclay platelets are obtained for functionalized protonated nanoclay. This behavior is attributed to the increase in the d‐spacing between the interlayers of the nanoclay during protonation and silanization. Tensile performances are found best with 0.5 wt% of silanized clay with an improvement of ~50%, ~84% and ~177% in strength, modulus and absorbed failure energy compared to neat epoxy. Although flexural and fracture performance are found highest with 2 wt% of silanized protonated clay with an improvement of ~57.5% in flexural strength and a remarkable ~241% and ~964% enhancement in fracture toughness and fracture energy compared to neat epoxy. The toughening mechanism investigation endorses the improvement in interfacial adhesion of the protonated silanized nanoclay that enhances the properties of the interfacial region, which significantly enhances the resistance for in‐panne crack propagation in epoxy nanocomposites.Highlights Synthesized silanized and silanized protonated montmorillonite clay. Protonation facilitated silane moiety attachment onto nanoclay. Maximum improvement of flexural strength by ~57.5% for ESPrC2. KIC and GIC were highest showing ~1.74 MPam1/2 and ~830.28 J/m2 for ESPrC2. Enhanced interfacial adhesion due to SPrC with the epoxy matrix.

Investigating the Sorption/Desorption of the Cationic Herbicide Paraquat in Clay Minerals Using Batch and Electro–Ultrafiltration Techniques

The sorption/desorption processes of the cationic herbicide paraquat (PQ) onto various clays, namely, kaolinite (KLN), illite (ILT), and montmorillonite (MNT), were investigated. After the attainment of sorption equilibrium, PQ was extracted from the clays by a double-stage desorption process utilizing an electro–ultrafiltration (EUF) procedure. The Freundlich isotherm model and a pseudo-first kinetic release model were found to adequately fit the sorption and desorption data, respectively. The experimental maximum sorbable amounts of paraquat were 5.56, 31.88, and 91.63 mg g−1 for KLN, ILT, and MNT, respectively, consistently with the order of magnitude of the cation-exchange capacity (CEC) of the clay minerals. The desorption experiments revealed that the amounts of PQ retained by the MNT samples were significantly larger than the respective amounts retained by KLN or ILT. The EUF-PQ desorption patterns of differently cation-saturated MNT samples indicated that the presence of monovalent cations could further hamper PQ release, while the opposite seemed to be true for divalent cations. Our results clearly show that a substantial aliquot of PQ is strongly retained by montmorillonite, probably via interlayering, thus suggesting that smectitic clays could act as a stable soil sink for cationic herbicides such as paraquat, favoring soil long-term contamination.

ENHANCEMENT OF SUB GRADE SOIL BY USING FLYASH AND LIME

Abstract -In India 15% of land is covered by Black Cotton Soil. The presence of montmorillonite clay mineral in the Expansive soil causes Swelling and shrinking properties which leads to major problems in Construction sites. This can be resolved by using soil stabilization techniques which enhances the engineering properties of soil. The soil stabilization is most important for the construction which is widely used in pavements or any other structures on expansive soil. Utilization of industrial waste materials in the improvement of soils is cost-efficient and eco-friendly method. In the present study an experimental investigation is taken to know the Geotechnical Characteristics of Expansive Soil with the Combination of FLYASH and LIME. In this study soil is mixed with the different proportions of (10%,20%,30% & 40%) FLYASH and (2.5%,5%,7.5%,10%,12.5% & 15%) LIME. The strength gained by soil is investigated by conducting California bearing ratio test & it is also calculated to reduce the thickness of the layer. The maximum dry density increased from 1.38g/cc to 1.54g/cc. The CBR un soaked test value enhances from 1.01% to 6.49% respectively Key Words: Black Cotton Soil, Fly ash, Lime, Compaction, maximum dry density, CBR

Nanoclay particles as a stem cell adhesion factor in polyvinyl alcohol hydrogel‐based wound dressings

AbstractAs the primary goal in the wound care intervention is the promotion of rapid wound healing, researchers sought to find a remedy. In this progression course, nanocomposite‐based hydrogels have attracted the attention. Herein, we used a polyvinyl alcohol (PVA) hydrogel in combination with two forms of clay nanoparticles, namely unmodified montmorillonite (MONT) and modified (OMONT), to fabricate a nanocomposite‐based hydrogels and combat the lack of stem cells' adhesion to PVA, followed by seeding of adipose‐derived stem cells (ADSCs) on them. To investigate the characteristics of these constructs, corresponding tests were performed. The Young's modulus and elongation at break of PVA/5% OMONT were 3.7 ± 0.014 and 800 ± 35, respectively, which were higher than those of PVA/5% MONT (3 ± 0.03 and 320 ± 14). In addition, the hardness of the modified group (7.2 ± 0.07) was lower than the unmodified one (9.8 ± 0.07). The water vapor transmission rate (WVTR) in the OMONT group was 39 ± 0.28, which was lower than PVA/5% MONT (46 ± 4.24). Hence, ADSCs/PVA montmorillonite dressing may improve wound healing and provide a new way to employ stem cells, significantly impacting skin tissue engineering safely.Highlights Modified montmorillonite had higher stem cell binding. The lack of stem cells' adhesion to polyvinyl alcohol (PVA) was solved. Adipose‐derived stem cells/PVA montmorillonite dressing may improve wound healing. It is a novel promising approach for skin tissue engineering.

Effect of interlayer cations on the adsorption of ionic liquid on montmorillonite clays: comparative study

Industries are the most important resource of water pollution due as a result of toxic pollutants including surfactant or ionic liquids. It becomes urgent to propose low cost and environmentally friendly involving the use of local resources. Here,one of the main ionic liquids (BMImCl) were intercalated into three alkaline-earth, Mg2+, Ca2+, and Ba2+ exchanged montmorillonites. For all samples interlayer spacing after intercalation are similar about 13 Å as measured by X-ray diffraction. These findings are compared with previous results on similar montmorillonite exchanged with every type of alkali cations, i.e. Li+, Na+, K+, Rb+, and Cs+. The basal spacing of intercalated montmorillonite increased as the ionic potential (Z/R) is increased. The FTIR is another tool to confirm the differences between modified and unmodified montmorillonite samples. More specifically, the results showed that the formation of new bands of vibrations (1400–1500 cm-1) and (2850–2900 cm-1).Thermal measurements indicate that homoionic clay display two distinct regions. ‎(I) from room temperature to 160 0C corresponding to physical adsorption and removal of water of hydration, (II) dehydroxylation of the silicate structure in the temperature range of 160-700 0C.

Ni Nanoparticles Supported Montmorillonite Clay for Selective Catalytic Transfer Hydrodeoxygenation of Vanillin into 2‐Methoxy‐4‐methylphenol

AbstractThe targeted catalytic transfer hydrodeoxygenation (CTHDO) of vanillin (VAN) to 2‐methoxy‐4‐methylphenol (MMP) holds promise as a noteworthy subject in the domain of bio‐oil utilization, offering potential as a future biofuel and finding versatile use in fragrances and pharmaceutical industry. In this study, stable, cost‐effective Ni nanoparticles supported on montmorillonite (MMT) clay was synthesized for eco‐friendly, alcohol‐mediated CTHDO of VAN to MMP. The Ni(10 %)/MMT catalyst achieved >99 % VAN conversion and 95.2 % MMP selectivity using isopropanol (IPA) as a solvent and hydrogen donor. Characterization encompassing PXRD, SEM, TEM, and XPS confirmed successful Ni integration onto MMT. NH3‐TPD, pyridine‐IR, and H2‐TPR analysis evaluated catalyst surface acidity and reducibility. The synergy between surface‐modulated acidity of MMT and Ni nanoparticles collectively facilitated IPA and VAN activation, driving CTHDO performance. The Ni(10 %)/MMT catalyst displayed sustained activity over five recycles. Its exceptional stability and performance underscore its potential as an eco‐friendly, sustainable, non‐noble transition metal‐based catalyst for the hydrogenating lignin bio‐oil model compounds, contributing to greener catalytic advancements.

Surface Modification of Montmorillonite Clay Towards the Fabrication of Nanocomposites for Engineering Applications

Montmorillonite (MMT) is a layered clay mineral composed of silica and alumina sheets with a layer thickness of about 1 nm qualifies it as a two-dimensional nanomaterial. MMT is found in natural clay ores in the Murunkan, Kirinda, and Okanda areas in Sri Lanka. Nanocomposites with enhanced physical and mechanical properties can be prepared by dispersing MMT in a polymer matrix. However, the hydrophilic nature of MMT hinders the incorporation of MMT into hydrophobic polymer matrices. Hence, a suitable surface modification is required to make MMT compatible with polymers. The present study was based on the preparation and analysis of organically modified calcium Montmorillonite (Ca-MMT)-polypropylene nanocomposites as a green technology initiative. Homo-ionic Ca-MMT was prepared by treating commercial MMT-K10 with a CaCl2 solution. The predominant exchangeable divalent cations present in MMT-K10 and Ca-MMT were determined using AAS. The cation exchange capacity of Ca-MMT was about two times greater than that of MMT-K10. Furthermore, XRD analysis showed a slight increase in d- spacing of Ca-MMT compared to MMT-K10. A novel ligand, triethylene glycol dodecyl methyl ether was synthesized by treating triethylene glycol monomethyl ether (TGME) with 50% w/w aqueous solution of sodium hydroxide followed by 1-bromododecane with the molar ratio of TGME:NaOH:1-bromododecane in 1:2:2. The crude product was purified by column chromatography and characterized by FTIR and GCMS analysis. Hydrophilic Ca-MMT was surface modified with the organic ligand presumably via the coordination of triethylene glycol moiety with Ca2+ cations at the outer edge of the MMT particles. The long aliphatic chains in the periphery of the modified MMT particle make it more organophilic. Modified Ca-MMT was characterized by XRD, TGA, and FTIR analysis. The XRD revealed a slight increase in the d-spacing related to the 001 plane of modified Ca-MMT compared to unmodified clay. The effect of modified Ca-MMT loadings (0.5%, 1%, and 1.5%) on the mechanical properties of the nanocomposite was studied. The results implied an enhancement of the mechanical properties in terms of impact resistance, hardness, and flexural properties in the nanocomposite compared to the virgin polymer. The fabricated nanocomposite is a promising engineering material that may have applications in automotive, construction, and packaging products.
 
 Keywords: Montmorillonite, Polypropylene, Nanocomposite, TGME, Compatibility

Montmorillonite clay modified by CuFe2O4 nanoparticles, an efficient heterogeneous catalyst for the solvent-free microwave-assisted synthesis of 1,3-thiazolidin-4-ones

Montmorillonite clay modified by CuFe2O4 nanoparticles, an efficient heterogeneous catalyst for the solvent-free microwave-assisted synthesis of 1,3-thiazolidin-4-ones

Montmorillonite clay decorated with Al-Mg LDH as a strong and retrievable nanocomposite for decontamination of wastewater containing chromium(VI) and arsenic(III) toxic ions

Montmorillonite clay decorated with Al-Mg LDH as a strong and retrievable nanocomposite for decontamination of wastewater containing chromium(VI) and arsenic(III) toxic ions

Organic Synthesis via Renewable Heterogeneous Nanocatalysts Based on Montmorillonite Clay

Abstract: Synthetic organic molecules are vital for human life, serving as medications, pesticides, dyes, and food additives. Organic synthesis provides routes for the production of these molecules. The traditional methods of organic synthesis require energy, solvents, time, and certain conditions based on the nature of the reactions. To address the issues associated with conventional processes, various environmentally friendly (green) methodologies have been developed. Catalysts are crucial in many chemical methods. Chemists aim to develop catalysts that are cost-effective, easy to recover, and can be synthesized with high catalytic activity and renewability. Natural montmorillonite clay is an ideal material for efficient catalysts since it satisfies all these requirements. This review focuses on the recent advances in the development of renewable nanocatalysts made from montmorillonite to be used for the synthesis of various organic compounds.

Mesoscale Behavior of Montmorillonite Clay Modified by a Responsive Polymer

Mesoscale Behavior of Montmorillonite Clay Modified by a Responsive Polymer

Biomechanically tunable scaffolds for bone tissue regeneration and testbeds of cancer bone metastasis

Current challenges in bone regeneration and design of humanoid 3D bone metastases cancer testbeds can be overcome by designing bone-mimetic tissue engineering scaffolds with tunable mechanical and biological properties. This study employs three unnatural amino acids to modify montmorillonite clay (MMT), producing polymer clay nanocomposites (PCNs) to construct 3D bone-mimetic scaffolds. The modification of MMT clay with 5-aminovaleric acid, (±)-2-aminopimelic acid, and 4-(4-Aminophenyl) butyric acid is analyzed through x-ray diffraction (XRD) and fourier-transform infrared spectroscopy (FTIR), revealing changes in the interlayer spacing and functional groups. Molecular modeling elucidates the interaction energies in the amino acid intercalated nanoclays that influence the mechanical properties of the scaffolds. 4-(4-Aminophenyl) butyric acid-modified scaffolds exhibited the highest compressive strength, highlighting the critical influence of molecular interactions on the mechanical properties of the PCN. Despite being a small fraction of the scaffold, the presence and type of amino acids significantly affect the scaffold mechanical properties. Cell viability assays affirm biocompatibility of scaffolds. The amino acids within the nanoclays also impact mineralization on scaffolds seeded with human mesenchymal stem cells (hMSCs). Amino acid type also influences the amount of mineralization in the scaffolds. A sequential culture involving hMSCs and breast cancer cells (MCF-7) on the scaffold mimics breast cancer metastasis to bone. Enhanced mineralization by bone cells in the presence of MCF-7 cells is observed, emphasizing their osteoblastic characteristics. Hence, 3D scaffolds for bone regeneration and bone metastasis cancer testbeds can exhibit tunable mechanical properties and biological responses though a simulation guided choice of unnatural amino acids.

Constraint on an RNA world on montmorillonite clay

Constraint on an RNA world on montmorillonite clay

Green synthesis of 1,3-Thiazolidin-4-ones derivatives by using acid-activated montmorillonite as catalyst

An environmentally friendly, clean, and applicable methodology for synthesizing 1,3-Thiazolidin-4-one derivatives was developed. This method produced the target compounds in high yields and short reaction times by using solvent-free reaction conditions with heterogeneous catalysts, montmorillonite (MT) and acid-activated montmorillonite (acid-MT). MT and acid-MT were investigated in the synthesis using a variety of techniques, including conventional heat, ultrasonic, and microwave irradiation, with the investigation of two types of factors, namely time and temperature. X-ray diffraction, N2 adsorption–desorption, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to characterize the MT and acid-MT catalysts. FTIR, 1H NMR, 13C NMR, and mass spectra were used to characterize each product. The ring-cyclization step, with its short time and high yield percentage, is the most important factor for the strength of the prepared catalyst, acid-MT. Additionally, the acid-MT catalyst was easily recoverable and can be reused up to five times without suffering a substantial reduction in catalytic activity.

A novel montmorillonite clay based bio-nanocomposite as an emerging biocontrol agent against stored grain pulse beetle

Chemical pesticides have been conventionally used to control the stored grain pest infestation, but these are hazardous to humans and the environment. Therefore, the herbal pesticides are gaining more importance in insect pest management. The montmorillonite (MMT) nanoclay, is found to be an effective and underexplored adsorbent for fumigant formulation against stored grain pests. Additionally, essential oils (EOs) and their derivatives offer promising alternatives to conventional insecticides, but their application is constrained by higher volatilization, rapid decomposition, and less persistency. To address the issue, this study focuses on purifying microporous MMT through the sedimentation method and encapsulating cinnamaldehyde from cinnamon essential oil to produce a bio-nanocomposite (CEB) for management of insect pest infestations. Furthermore, the raw MMT, purified MMT, and CEB were characterized by different physiochemical techniques such as X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The SEM-EDX analyses demonstrated shiny irregular sheets and confirmed the presence of C-atom along with Si, O, Al, and Mg. The average crystallite size for CEB is specified to be 9.69 nm. The persistency of the cinnamaldehyde and its effective release from the CEB was confirmed by FT-IR analysis until 30 days. CEB displayed potent fumigant toxicity (LC50 = 0.37 mg/cm3) and high repellency (93.33 %) against Callosobruchus chinensis. Quantitative analysis recorded elevated protein levels (5.47 mg/ml) in treated insects. Similarly, the qualitative analysis revealed up and down-regulation of six and eight protein bands, respectively. Overall, findings show that the formulated bio-nanocomposite can better manage pulse beetle infestations in stored grains.

Montmorillonite-catalysed coupling reactions: a green overview.

Coupling reactions are widely significant in organic synthesis, and within the green chemistry perspective the utilization of montmorillonite clay as a catalyst offers a viable alternative to traditional coupling protocols. Montmorillonite clay is an effective, eco-friendly, economic and recyclable catalyst, and its heterogeneous nature facilitates easy isolation and reusability. The majority of coupling reactions executed with montmorillonite catalysts offer notable advantages over their homogeneous counterparts, including enhanced efficiency, selectivity, operational simplicity, elimination of toxic solvents and ligands, maintenance of mild reaction conditions, and cost-effectiveness. This review gives a comprehensive summary of the literature to date on coupling reactions catalysed by montmorillonite clay, while also outlining future prospects in this area.

Clay based heterogeneous catalysts for carbon-nitrogen bond formation: a review.

Clay and modified clay-based catalysts are widely used in organic transformation. Owing to the interlayer ions and good ion exchange capacity of clay, replacement with another ion and incorporation of different nanomaterials can be done. Due to these significant properties of clay, it can be utilized in the synthesis of various organic compounds. Carbon-nitrogen bonded compounds possess diverse applications in different fields. These compounds are prepared using different solid acid heterogeneous catalysts. This review presents a detailed discussion on clay used for the carbon-nitrogen bond formation reaction, such as the Biginelli reaction and A3 and KA2 coupling reactions. Additionally, other C-N bond formation reactions using various clay-based catalysts such as bentonite, montmorillonite, hydrotalcite and halloysite clay with various metals, metal oxides, Kegging type heteropoly acid and various nanomaterial incorporated clay heterogeneous catalysts are discussed.