Montmorillonite K10 Research Articles

Organometallic modified montmorillonite application in the wastewater purification: Pollutant photodegradation and antibacterial efficiencies

The ability of peptides to form stable complexes with metal ions offers a remarkable starting point for elaborating catalysts and antibacterial agents.This paper reports the synthesis and characterization of a new inexpensive organometallic-montmorillonite as highly active catalyst and antibacterial agent. An Fe(II)-Glycylglycylglycine (Fe-3Gly) complex was covalently anchored to montmorillonite K10 (K10) previously grafted with 3-aminopropyl-trietoxisilane (APTES). Multiple techniques were used to investigate the different steps of functionalization, to name FTIR, TGA, XRD, N2 adsorption–desorption technique, RD/UV–Vis, and SEM-EDS. The catalytic activity of the prepared catalyst was determined in terms of decolorization efficiency percentages of Congo Red dye (CR) in an aqueous solution using three types of Advanced Oxidation Processes (AOPs) that are the heterogeneous Fenton, the photocatalysis and photo-Fenton processes. A full factorial design of experiment was established in the photo-Fenton process in order to i) identify the most influential parameters and their interactions, and ii) determine the experimental conditions most favorable to the degradation. Thus, five factors were considered: catalyst weight (X1), H2O2 volume (X2), pH (X3), CR concentration (X4) and time (X5). From the statistical analysis, the correlation coefficient for the model was R2 = 0.90 and the most effective factor in the photo-Fenton degradation efficiency was the pH. The experimental values fitted with the predicted ones, thereby indicating the appropriateness of the established model. Furthermore, the prepared material showed good antibacterial activities.

Substantial improvement in the adsorption behavior of montmorillonite toward Tartrazine through hexadecylamine impregnation

In the present work, the surface of montmorillonite K10 was successfully modified by hexadecylamine surfactant (Mt-HDA) and its intercalation and characteristics were assessed by XRD, FTIR, SEM, EDX and BET methods. Also, its adsorption performance was systematically examined in the removal of Tartrazine (TZ), as a sulfonated azo dye model, from aqueous phase. Our results showed that the HDA modification remarkably improved the adsorption ability of montmorillonite toward TZ molecules. The highest adsorption efficiency was achieved >98% at the pH range of 4–6 within a fast process (less than 30 min). The maximum adsorption capacity Mt-HDA toward TZ molecules was found to be ~59 mg/g at 45 °C. The kinetic study indicated that the adsorption kinetic follows pseudo-second-order model, which shows the chemisorption process between Mt-HDA and TZ molecules. Besides, the adsorption isotherm showed the monolayer coverage of Mt-HDA surface adsorption sites, which was fitted with the Langmuir isotherm model in an exothermic process. The adsorption mechanism was studied.

Critical assessment of structural changes in some copolyamide‐clay hybrid materials in correlation with the filler characteristics

AbstractA series of three copolyamide‐clay hybrid nanocomposites were prepared using three different smectite clays (bentonite, montmorillonite K10, and Nanomer I.30P) by a solventless melt mixing process. The influence of the nature of clays on the structural changes was critically assessed by comparison with the neat copolyamide. Nanocomposite samples were analyzed by scanning electron microscopy (SEM), wide angle X‐ray diffractometry (WAXD), UV–vis spectrometry and differential scanning calorimetry (DSC). The testing yielded in direct and indirect evidences of structural changes induced by the presence of clays in correlation with their characteristics, as nature of the clay, particle size, granulometric distribution, and particle dispersion into the matrix.

Copper(II) Anchored on Amine-Functionalized MMT: A Highly Efficient Catalytic System for the One-Pot Synthesis of Bispyrano[2,3-c]pyrazole Derivatives

In this study, preparation of pyridine-2-carboimine copper complex immobilized on amine-functionalized nanoclay montmorillonite K10 was reported. The products were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and thermogravimetric analysis (TGA). The catalytic activity of this new nanocatalyst, as a natural, renewable, inexpensive, and heterogeneous catalyst, was very effective for the four-component condensation reaction of hydrazine hydrate (or phenyl hydrazine), malononitrile, β-ketoester, and terephthalaldehyde (or isophthalaldehyde) toward the synthesis of multisubstituted bispyrano[2,3-c]pyrazole derivatives. From the viewpoint of green chemistry, the advantages of this approach are accessibility, simplicity, and high yields synthesis. The catalyst was recycled and reused four times without significant loss of activity.

Ionic liquid-based dispersive liquid–liquid microextraction followed by dispersive solid phase extraction coupled with HPLC-DAD for the determination of sulfonylurea herbicides in soymilk samples

The ionic liquid-based dispersive liquid-liquid microextraction followed by dispersive solid phase extraction (IL-DLLME-DSPE) was developed and applied to the extraction of six sulfonylurea herbicides in soymilk samples. High performance liquid chromatography coupled with a diode-array detector was used for the separation and determination of analytes. In this study, [P4 4 4 12] [BF4] was used as an extraction solvent in DLLME and montmorillonite K10 was used as an adsorbent in DSPE. After DLLME and DSPE, the ionic liquid and analytes were adsorbed by montmorillonite K10 and separated from the sample solution. Subsequently, the analytes were desorbed from montmorillonite K10 by acetonitrile. Some parameters, including type and amount of ionic liquid, pH of sample solution, centrifugal speed, and amount of montmorillonite K10, were investigated and optimized. The limits of detection and quantification for analytes were in the range of 1.53–2.32 and 5.10–7.73 µg L−1, respectively. The relative standard deviations for intra-day and inter-day precision were in the range of 1.12–3.59 and 1.99–6.48%, respectively. When the present method was applied to the analysis of real soymilk samples, the recoveries of the analytes were 81.95–118.95%. The results showed that the present method is effective for the extraction of the sulfonylurea herbicides in soymilk samples.

One-Pot Green Synthesis of Acridine Alkaloid Derivatives and Screening of in vitro Anti-cancer Activity Against Cdc25b and SHP1.

To develop anti-cancer active pharmaceutical intermediates. Acridone derivatives possess a wide range of pharmacological activities: 1) they intercalate DNA and 2) form a covalent bond with DNA. To screen in vitro anti-cancer activity against Cdc25b and SHP1 of new acridone derivatives and preliminary study on the structure-activity relationship. The synthesis of new acridone derivatives and in vitro evaluation of their anti-cancer activity on Cdc25b and SHP1 was achieved. Natural products that contain acridine structures, such as cystodytin A and acronycine, are isolated from certain marine (tunicates & ascidians, sponges, sea anemones) and plant (bark of Australian scrub ash tree) species. Herein, we report the efficient one-pot green synthesis of twelve novel 3,4-dihydro-1 (2H) acridone derivatives, using montmorillonite K10 as the catalyst and iron/citric acid in water. Also, their inhibitory activity against Cdc25B and SHP1 is examined, in which specific derivatives show enhanced inhibitory activity compared to others. Twelve new acridone derivatives were prepared, starting from 2-nitrobenzaldehyde derivatives and 1, 3-cyclohexanedione derivatives, which exhibited substantial anti-cancer activity against Cdc25b and SHP1 cells. Preliminary studies on the structure-activity relationship have shown the influence of the structural parameters and, in particular, the nature of the substituent on aromatic ring structure and cyclohexanone. Other: Further study on the structure-activity relationship is required.

Catalytic activity of K10 montmorillonite in the chemical vapor deposition of multi-wall carbon nanotubes from methane

The catalytic activity of K10 montmorillonite (K10Mt) as a substrate during the chemical vapor deposition (CVD) of carbon nanotubes (CNT) was investigated. The influence of free iron present in the structure of K10Mt during CNT synthesis was investigated. The synthesis was carried out both on samples containing free iron and after its chemical extraction. The structural and microstructural parameters of the samples were characterized by scanning electron microscopy with X-ray dispersion spectroscopy (SEM/EDS), energy dispersive transmission electron microscopy (TEM/EDS), X-ray fluorescence spectroscopy, X-ray diffraction (XRD), infrared spectroscopy (FTIR), and Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that K10Mt, before Fe removal, was covered with coarser forms of carbon with rounded shapes characteristic for pyrolytic carbon deposits, while after chemical purification the K10Mt particles were covered with regular forms of CNT. During the CVD process at 850 °C, multi-walled carbon nanotubes about 1 μm in length were formed on the surface of pure K10Mt. Under the conditions of synthesis, the K10-Mt/CNT nanocomposites were formed. After extraction of free iron from K10Mt, the most likely nucleation sites for CNT growth were Mg- and Fe-containing compounds structurally integrated with the K10Mt substrate, such as iron phosphides, magnesia, and magnesium aluminate.

Oxidative study of Acid Yellow 23 using K10-Montmorillonite chemically modified

Catalytic ozonation of the azo dye Acid Yellow 23 was investigated in the presence of Montmorillonite K10 and its chemically modified counterpart with Cobalt and Nickel (Co-Ni-K10). The material thus obtained were characterized by BET, XRD and TGA analysis. The effects of different variables were studied, such as: catalyst dose, ozone dose, ozonation time and pH. Clay-catalysed reactions are strongly dependent on the adsorption of the reactant, which in turn should depend on acid-base, electrostatic and hydrophilic-organophilic interactions. The basicity of the clay catalyst surface is expected to favour the interactions with the acidic groups of the studied organic molecule. The interactions involved in adsorption are determined by the pKa values of each group in each organic molecule.

Promising extruded catalyst for palm oil transesterification from LiAlH4 hydrolysates

Transesterification catalysts prototypes of LiAlP/montmorillonite from LiAlH4 hydrolysates (LiOH-Al(OH)3) have been synthesized and extruded. The extruded catalysts preserve the basic structure of montmorillonite K10 according to X-ray diffraction results, which promote transesterification of triglycerides present in palm oil with methanol to generate FAMEs. Palm oil conversions of up to 89.7% were achieved in a batch reactor at 200 °C, 40 Kg/cm2, and MeOH:Oil molar ratio of 18:1. The results obtained suggest that the good catalytic activity of the extrudates is due to the adequate combination of the Lewis acid sites and the mesoporous structure obtained during the reaction between the montmorillonite, phosphoric acid and LiOH-Al(OH)3. By mean of B3LYP/6-31G* calculations, the behavior of the electrophilicity for the palm oil triglycerides and the corresponding H, Li and Al cations is remarkable, the highest electrophilicity for cation is in this order: H > Al > Li and more important for triglyceride aluminum cation in which palmitoyl moiety is in the methine carbon of glycerol moiety.

Microwave-assisted fabrication of ZnO/MK10 nanocomposite: an efficient photocatalytic and sonophotocatalytic degradation of methylene blue dye

In this research, we have designed a microwave-assisted procedure for processing of ZnO nanoparticles (ZnO NPs) modified by Montmorillonite K10 (MK10) nanosheets in a one-pot strategy using Carrisa edulis fruit extract as the capping agent. The sample was characterized with X-ray diffraction, infrared, ultraviolet–visible spectroscopy, transmission electron microscopy, X-ray diffraction, atomic force microscopy, zeta potential, and photoluminescence. We observed that the ZnO/MK10 nanocomposite exhibited superior photocatalytic ability toward methylene dye (MB) degradation. ZnO/MK10 nanocomposite shows excellent sonophotocatalytic effect, which is three times higher than that of MB photocatalytic effect. This nanocomposite has been further active in trapping species, potential mechanism for sonophotocatalytic degradation, excellent recyclability, and stability.

Montmorillonite Catalyzed Tandem Synthesis of 1,1,3-Trisubstituted-1H-Isochromenes from 3-Phenylisochromenones

An efficient synthesis of 1,1,3-trisubstituted-1H-isochromenes, 3 is reported from isochromen-1-ones, 1 and Grignard Reagents, 2a-h through sequential Grignard reactions/acid-catalyzed cyclization. The cyclization underwent smoothly with montmorillonite K10 catalyst to obtain the 1,1,3-trisubstituted-1H-isochromenes in excellent yields.

Mild upgrading of biomass pyrolysis vapors via ex-situ catalytic pyrolysis over an iron-montmorillonite catalyst

Pyrolysis vapor upgrading can improve the stability of pyrolysis liquids to facilitate storage, transport, and drop in use as fuels and chemical feedstocks in existing refining infrastructure. This study investigates a low cost iron based catalyst for mild in-situ upgrading of fast pyrolysis vapors to increase the stability of pyrolysis liquid. Iron-doped montmorillonite K10 catalysts were characterized by ICP-OES, BET porosimetry, XRD, XPS, and NH3-TPD. The effect of three upgrading process parameters are evaluated by Box-Behnken experimental design using a fixed catalyst bed. Predictive model equations are developed based on response surface methodology to describe the effect of iron loading, catalyst to biomass ratio, and catalyst bed temperature on yields of pyrolysis liquids, non-condensable gas, and coke on the catalyst. Compared to non-catalytic pyrolysis, pyrolysis vapor upgrading over iron catalyst reduce pyrolysis liquid yields and increase gas yields as pyrolysis vapors are catalytically cracked into lighter molecules. Liquid yield decreases with C:B ratio while gas yields increase. By increasing Fe loading from 0% to 10%, catalyst coking decreases from 11.7% to 3.5% yield. Iron loading of 10% is the least susceptible to coking, but results in greater amounts of polyaromatics in the pyrolysis liquid product. According to GCMS analysis of the pyrolysis liquids, upgraded pyrolysis liquids have lower concentrations of unstable carboxylic acids and aldehydes. In addition, formation of phenols shift towards a greater fraction of alkyl phenols and lower fraction of methoxy phenols leading to a more stable liquid product as a result of upgrading. Overall, iron-doped montmorillonite catalyst is demonstrated to be a viable, low cost catalyst for mild upgrading of fast pyrolysis vapors.

Michael addition of ethyl anthranilate and phenyl monothioanthranilate to acetylenic esters: experimental and theoretical results

The reaction of ethyl anthranilate with DMAD and with methyl propiolate in dichloromethane in the presence of ethylaluminium dichloride as catalyst at room temperature gives a mixture of the respective E- and Z-intermediate derivatives which do not cyclize even on refluxing for several hours. On carrying out the reaction in refluxing methanol in the absence of the catalyst, only one stereochemical isomer is obtained which is Z-intermediate indicating conversion of less stable isomer into the thermodynamically more stable derivative under these conditions. The resulting product did not cyclize even on refluxing in methanol in the presence of montmorillonite K10 clay catalyst. The reaction of phenyl monothioanthranilate with DMAD and with methyl propiolate gives similar results. A theoretical investigation of the reaction of ethyl anthranilate with methyl propiolate at the B3LYP/6-31 + G(d) level reveals that it occurs in five steps.

Preparation of α-Terpineol from Biomass Resource Catalysed by Acid Treated Montmorillonite K10

A new type of heterogeneous catalyst for hydration of α-pinene was prepared. Montmorillonite K10 was treated by various acids (H2SO4, HCl, HNO3, and ClCH2COOH) and successfully used for the mentioned reaction. The used characterization techniques showed that the acid treatment improved the properties of K10 important for the catalytic activity (SBET and acidity). On the other hand, the morphology and particle size distribution remained the same. Regarding the selectivity (side and consecutive reactions can proceed), the optimal reaction conditions were found (temperature, type of the catalyst, amount of the catalyst, molar ratio α-pinene: water, type of water, solvent). Using the optimal reaction conditions, 60% conversion of α-pinene was achieved with 45% selectivity to α-terpineol (80 °C, 25 wt% of K10/HCl, or K10/H2SO4, nα-pinene:nwater 1:7.5, 1,4-dioxane as a solvent, 24 h). Higher conversions of α-pinene, as well as higher selectivity to α-terpineol, were achieved using all acid treated K10 in comparison to raw K10. Considering the heterogeneous form of prepared catalysts, its availability, low price and easy method of preparation, these catalysts dispose of a large potential for application as catalysts for hydration reactions.

Molybdenum oxide modified montmorillonite K10 clay as novel solid acid for flow synthesis of ionone isomers

Molybdenum oxide modified montmorillonite K10 clay (Mt-K10) was developed to synthesize ionone isomers via cyclization of pseudoionone. A fixed bed flow reactor was used to convert the current homogenous batch process into a heterogeneous flow process. To increase the acidity, molybdenum oxide was loaded on Mt-K10. Since molybdenum oxide contains both Lewis and Bronsted acidity, the loading resulted in a higher acidity of 1% (w/w) MoO3/Mt-K10 catalyst compared to Mt-K10 alone. 1% (w/w) MoO3/Mt-K10 is new, green, and economical catalyst derived from ammonium heptamolybdate tetrahydrate as molybdenum precursor and using Mt-K10 as support. The support and catalyst were analyzed by various characterization techniques, including XRD, FTIR, NH3-TPD, BET, SEM, TEM, and XPS analysis. Thus, 100 % conversion of pseudoionone and 75 % selectivity of ionone isomers were obtained. 1% (w/w) MoO3/Mt-K10 catalyst could be easily prepared on a large scale and it is effective in the synthesis of isomers of ionone with higher selectivity in comparison with other solid acids.

Optimization studies on esterification of waste cooking oil using sulfated montmorillonite clay acidic catalyst

Currently, refined edible oils are used to produce biodiesel with the help of a base catalyst. The most important problem with the base-catalyzed esterification process is that they produce soap when they have higher free fatty acids (FFA). The present study indicates that montmorillonite (k10) can be a significant catalyst prepared by the impregnation method using H2SO4 in the ratio of 1:5. The prepared novel catalyst was characterized using XRD, FTIR and SEM-EDS techniques. The optimum conditions for esterification have been determined by applying RSM with CCD methodology for each significant variable like oil-methanol molar ratio, catalyst amount, reaction time and temperature. The optimum acid conversion of 80.8% was observed at an oil-methanol molar ratio of 1:12, amount of catalyst 6 wt% and 120 min of reaction time at 55 °C.

Rearrangements of the Betulin Core. Synthesis of Terpenoids Possessing the Bicyclo[3.3.1]nonane Fragment by Rearrangement of Lupane-Type Epoxides.

The rearrangements of dihydrobetulin, dihydrobetulinic acid, and abeo-lupane epoxides under acidic conditions (HCl, montmorillonite K10, and BF3·Et2O) were studied. The treatment of dihydrobetulin with HCl or K10 produced abeo-lupane olefins. Their epoxidation afforded epoxides, which, in the presence of protic or Lewis acids, rearranged to dienes or lupanes bearing a bicyclo[3.3.1]nonane fragment. The structure of final products depended on the nature of the catalyst. The HCl promoted 1,4-elimination of water, whereas in the presence of BF3·Et2O bond migration took place preferentially. Montmorillonite K10 favored cyclization to bicyclononane.

Toward a New Way for the Valorization of Miscanthus Biomass Produced on Metal-Contaminated Soils Part 2: Miscanthus-Based Biosourced Catalyst: Design, Preparation, and Catalytic Efficiency in the Synthesis of Moclobemide

The conception of two biosourced catalysts (biocatalysts) using stems of miscanthus from the first part of this study are described herein. The temperature and the process used to extract metals from plant as mixture of Lewis acids were investigated in detail and proved to be essential in the design of the biosourced catalysts and their catalytic efficiency. One part of the crude mixture of Lewis acids extracted from the aerial parts of miscanthus plants was used without further treatment as a homogeneous biocatalyst (M1), and the other part was supported on montmorillonite K10 to provide a heterogeneous biocatalyst (MM1). M1 and MM1 were next tested in the synthesis of moclobemide (main ingredient of a drug used to treat depression) and led to excellent yield. Additional comparative experiments with different commercial metallic salts (NaCl, KCl, CaCl2, MgCl2, CuCl2, ZnCl2, FeCl2, FeCl3, MnCl2, and AlCl3) and their mixtures were carried out and underlined the importance of the multimetallic synergy on catalytic activity. Finally, a comparison of this new synthetic method assisted by the biosourced catalyst with the previously described procedures to access moclobemide was realized by calculating their green chemistry metrics. This study revealed that the use of the biosourced catalyst led to one of the greenest synthetic methods described today to produce moclobemide.

Development of nickel and silver ceramic filters supported on K10 montmorillonite clay for water disinfection

Abstract This study aimed to obtain ceramic filters with bactericidal action for water disinfection. For this, aqueous suspensions of montmorillonite K10 clay were prepared at concentrations of 48%, 50%, and 52%. Later, these were impregnated into polymeric sponges in order to form the ceramic skeletons by using the replica technique. The ceramic filters were submerged in nickel resins doped with 0.25 and 0.50 mol% silver. These resins were obtained by the Pechini method and heat-treated at 600 and 700 ºC for 2 h. Moreover, techniques such as X-ray diffraction, particle size analysis, scanning electron microscopy, energy dispersive spectroscopy, compressive strength, water absorption, and apparent porosity were used to characterize the filters, and their performance was analyzed by a bactericidal test. The bactericidal test results showed that the filters impregnated with the resin containing 0.50 mol% of silver promoted the total elimination of the Staphylococcus aureus and Escherichia coli bacteria.

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