Montmorillonite KSF Research Articles

Photodegradation of bisphenol AF in montmorillonite dispersions: Kinetics and mechanism study

The photodegradation behavior of bisphenol AF (BPAF) in montmorillonite KSF dispersions was investigated. The influence of KSF dosage, initial BPAF concentration and initial pH on the degradation of BPAF was studied. The main purposes were to clarify the degradation mechanism of BPAF and quantify the fluorine concentration during the degradation. At an initial concentration of 40 μM, more than 78% TOC was removed within 600 min irradiation, and the concentration of fluorine was 0.62 mg L − 1 . Degradation of BPAF followed the Langmuir–Hinshelwood kinetics rate model and the reaction rate constant k re was 0.887 μM min − 1 . Hydroxyl radicals were the main reactive species in the irradiated KSF dispersion. Intermediates of BPAF decomposition were determined by LC–MS analysis.

Montmorillonite KSF as catalyst for degradation of acetaminophen with heterogeneous Fenton reactions

The degradation of acetaminophen (APAP) in aqueous solutions with heterogeneous Fenton reactions was investigated with montmorillonite KSF as catalyst. The influencing factors of the initial APAP concentration, initial pH value, initial KSF dosage and H2O2 dosage were studied. The results showed that APAP could be effectively degraded under the conditions of pH 4.0, KSF 0.2 g/L and H2O2 0.5 mM, and the degradation efficiency of 0.5 mg/L APAP reached 93.5% after reaction for 30 min. The degradation kinetics of APAP followed the pseudo first-order rate law.

ChemInform Abstract: Montmorillonite KSF Clay as Novel and Recyclable Heterogeneous Catalyst for the Microwave Mediated Synthesis of Indan‐1,3‐diones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Role of clays in the prebiotic synthesis of sugar derivatives from formamide

We describe here the role of montmorillonite KSF in the prebiotic synthesis of amino sugar derivatives starting from a mixture of formamide and formaldehyde as simple chemical precursors. Since amino sugars are key intermediates in the synthesis of complex nucleic acid derivatives, this procedure opens a novel pathway for the formation of nucleosides under plausible primordial conditions.

Microwave-assisted synthesis of photochromic fulgides

The oxazole and indole based heterocyclic photochromic fulgides were synthesized from their corresponding fulgenic acid derivatives by clay catalysed microwave irradiation methodology. Improved yields of fulgides were observed by the microwave irradiation method as compared other chemical methods employed so far. The proportions of clay (montmorillonite KSF) and isopropenyl acetate play a key role in increasing the yields of fulgides.

Ultrasound promoted selective synthesis of 2-aryl-5,6-dihydro-4 H-1,3-oxazines catalyzed by K-10 and KSF montmorillonite clays: A practical procedure under mild and solvent-free conditions

Montmorillonite K-10 and KSF were found to be highly efficient, environmentally friendly and recyclable heterogeneous catalysts for the selective synthesis of a variety of 2-aryl-5,6-dihydro-4 H-1,3-oxazines from arylnitriles and 3-amino-1-propanol under ultrasound irradiation. This new methodology provides excellent yields in short reaction times (10–25 min). The reaction work-up is very simple and the catalysts can be easily separated from the reaction mixture and reused several times in subsequent reactions. This catalytic system also exhibits excellent chemoselectivity in the synthesis of mono-oxazines from dinitriles.

New strategy for the synthesis of novel spiro[indoline-3,2'-thiazolo[5,4-e]pyrimido[1,2-a]pyrimidine] derivatives

An environmentally benign, efficient and facile route is developed for the synthesis of novel spiro[indoline-3,2'-thiazolo[5,4-e]pyrimido[1,2-a]pyrimidine] derivatives. The benzylidene derivatives of spiro[indoline-thiazolidinones] 6 containing an α,β-unsaturated ketonic function [CH=CH-CO-] have been used as a component of Michael addition with an equimolar amount of 2-aminopyrimidine 7 to give a series of novel spiroindole derivatives 9 in a single step using montmorillonite KSF as inorganic solid support with few drops of DMF. In comparison to conventional synthesis involving tedious multistep procedures, the present method indicates operational simplicity, shorter reaction time and higher yields which can prove this procedure as a useful alternative for the synthesis of novel spiro heterocycles.

Photodegradation of paracetamol in montmorillonite KSF suspension

Photodegradation of paracetamol in montmorillonite KSF suspension followed the Langmuir–Hinshelwood kinetic model. The influence of KSF dosage, initial paracetamol concentration, initial pH, chelating agents and a radical scavenger on the degradation of paracetamol were studied and described in detail. The degradation mechanism of paracetamol was also proposed in this work.

Montmorillonite KSF Clay as Novel and Recyclable Heterogeneous Catalyst for the Microwave Mediated Synthesis of Indan-1,3-Diones

Various indan-1,3-dione derivatives were synthesized from the reaction of different phthalic anhydrides with diethylmalonate using montmorillonite KSF clay as a recyclable heterogeneous acidic catalyst and microwave irradiation in good yields and short reaction times.

Montmorillonite clay-catalyzed cyclotrimerization and oxidation of aliphatic aldehydes

A temperature-dependent equilibrium is observed for the cyclotrimerization of aliphatic aldehydes in the presence of Montmorillonite K10 clay, while aerobic oxidation of aliphatic aldehydes to the corresponding carboxylic acids is favored at room temperature in the presence of Montmorillonite KSF clay.

Photodegradation of chloroform in aqueous solution: Impact of montmorillonite KSF particles

In this work, photodegradation of chloroform in water suspensions of montmorillonite KSF (KSF) under a black light lamp ( λ = 365 nm) was investigated. The results showed that KSF induced the photodegradation of chloroform by producing hydroxyl radical ( OH) that oxidized chloroform in the heterogeneous clay–water systems. The photodegradation of chloroform in KSF suspensions was greatly influenced by the concentration of KSF and the pH of KSF suspensions. The photodegradation of chloroform by KSF followed the Langmuir–Hinshelwood Model. Furthermore, the removal efficiency of chloroform can be enhanced by the presence of carboxylates (oxalate and citrate) and humic acid (HA). This work demonstrates that KSF can be used as a new and efficient photocatalyst in oxidation and removal of organic compounds.

Preparation and characterization of aluminum pillared K10 and KSF for adsorption of trimethoprim

Montmorillonite KSF and K10 were used as precursor materials for synthesis of aluminum pillared K10 and KSF (Al-K10 and Al-KSF) which characterized by TGA, XRD, SEM and FT-IR spectroscopic analysis. The sorption of trimethoprim (TMP) which is commonly employed as an antibiotic onto Al-K10 and Al-KSF was also investigated as a function of adsorbent dosage, solution pH, contact time and temperature. The adsorption kinetics was interpreted using pseudo-first-order, pseudo-second-order kinetic models and intraparticle diffusion model. The pseudo-second-order model provided the best correlation. Adsorption isotherm parameters were obtained from Freundlich, Langmuir and Dubinin–Radushkevich (DR) isotherm models. Adsorption of TMP onto Al-K10 and Al-KSF was physical in nature and ion-exchange mechanism for DR equation, respectively. Al-K10 exhibits higher removal capacity at lower adsorbent dosages in comparison with Al-KSF. The removal capacity was increased by increasing pH. Δ H 0, Δ S 0 and Δ G 0 showed that adsorption of trimethoprim was endothermic, increasing randomness and not spontaneous in nature.

Cerbera odollam (sea mango) oil as a promising non-edible feedstock for biodiesel production

This paper explores the feasibility of converting Cerbera odollam (sea mango) oil into biodiesel. The first part of this study focused on the extraction of oil from the seeds of C. odollam fruits, whereas the second part focused on the transesterification of the extracted oil to fatty acid methyl esters (FAME). The transesterification reactions were carried out using three different catalysts; sodium hydroxide (NaOH) as a homogenous catalyst, sulfated zirconia alumina and montmorillonite KSF as heterogeneous catalysts. The seeds were found to contain high percentage of oil up to 54% while the yield of FAME can reach up to 83.8% using sulfated zirconia catalyst.

Synthesis and pharmacological evaluation of antioxidant chalcone derivatives of 2(3H)-benzoxazolones

Chalcones featuring an analgesic/anti-inflammatory pharmacophore, i.e., the 2(3H)-benzoxazolone heterocycle, on the one hand, and a radical scavenger moiety, i.e., 2,6-di-t-butylphenol, on the other hand were synthesized by condensation of a ketone 2(3H)-benzoxazolone precursor with 3,5-di-t-butyl-4-hydroxybenzaldehyde. Among the various methods explored (acid homogenous or heterogenous catalysis, base catalysis), heterogenous catalysis conditions using KSF Montmorillonite were found to be the most convenient. The E-geometry of the so-obtained chalcones was ascertained both by 1H and 13C-nuclear magnetic resonance (NMR) spectroscopy as well as B3LYP/6-31G** quantum mechanics calculations. Chalcones 1–8 were pharmacologically evaluated in vitro for their ability to prevent human low-density lipoprotein (LDL) copper-induced oxidation using Cu2+ as oxidizing agent. Compound 4 emerged as the most promising agent as it was able to inhibit copper-mediated human LDL oxidation with an activity ten times greater than that of Probucol, a reference antioxidant drug.

Degradation of Orange II by heterogeneous photocatalytic reaction using montmorillonite KSF

Degradation of Orange II in montmorillonite KSF (KSF) suspensions under irradiation by a 250 W metal halide lamp (λ ≥ 365 nm) was investigated. The degradation kinetics of Orange II in KSF suspensions followed the Langmuir-Hinshelwood model. The effects of KSF concentration, solution pH, initial Orange II concentration, carboxylic salts were studied.

Photodegradation of Bisphenol A in the Montmorillonite KSF Suspended Solutions

The commercially available montmorillonite KSF is utilized as efficient acidic catalyst in organic synthesis chemistry. In this study it is used as a photoactive reagent in a heterogeneous system. A series of experiments of the degradation of bisphenol A (BPA) as a model organic pollutant in montmorillonite KSF suspended solutions under UV−vis irradiation (metal halide lamp, λ ≥ 365 nm) were investigated. It is found that BPA could be effectively photodegraded in suspension. The BPA photodegradation is dependent on the pH of the solution and dosage of clay minerals, and it is more effective for BPA to be degraded at pH 4; the degradation rate of BPA increased with the concentration of clays in the range of 0.5 g/L to 5 g/L. The photodegradation rate of BPA is fitted well into the Langmuir−Hinshelwood equation. Results also indicate that the carboxylate and dissolved oxygen could efficiently enhance the degradation rate, and the role of carboxylate in accelerating the photodegradation of BPA follows the order: pyruvate > oxalate > citrate.

Evidence of the hydroxyl radical formation upon the photolysis of an iron-rich clay in aqueous solutions

With the use of laser flash photolysis, the formation of hydroxyl radicals upon the photolysis of an iron-rich clay (montmorillonite KSF) was demonstrated. The •OH radical was shown to be formed by the photolysis of the Fe(OH)aq 2+ complex that escaped from the clay into the solution bulk.

Biodiesel production from palm oil via heterogeneous transesterification

Abstract This paper presents the study of the transesterification of palm oil via heterogeneous process using montmorillonite KSF as heterogeneous catalyst. This study was carried out using a design of experiment (DOE), specifically response surface methodology (RSM) based on four-variable central composite design (CCD) with α (alpha) = 2. The transesterification process variables were reaction temperature, x 1 (50–190 °C), reaction period, x 2 (60–300 min), methanol/oil ratio, x 3 (4–12 mol mol −1 ) and amount of catalyst, x 4 (1–5 wt%). It was found that the yield of palm oil fatty acid methyl esters (FAME) could reach up to 79.6% using the following reaction conditions: reaction temperature of 190 °C, reaction period at 180 min, ratio of methanol/oil at 8:1 mol mol −1 and amount of catalyst at 3%.

Feasibility of Palm Oil as the Feedstock for Biodiesel Production via Heterogeneous Transesterification

AbstractThe production of biodiesel has become popular recently as a result of increasing demand for a clean, safe and renewable energy. Biodiesel is made from natural renewable sources such as vegetable oils and animal fats. The conventional method of producing biodiesel is by reacting vegetable oil with alcohol in the presence of a homogenous catalyst (NaOH). However, this conventional method has some limitations such as the formation of soap, usage of significant quantities of wash water and complicated separation processes. Heterogeneous processes using solid catalysts have significant advantages over homogenous methods. Currently, more than 90 % of world biodiesel is produced using rapeseed oil. The production of biodiesel from rapeseed oil is considered uneconomical, considering the fact that palm oil is currently the world's cheapest vegetable oil. Therefore, the focus of this study is to show the feasibility of producing biodiesel from palm oil using montmorillonite KSF as a heterogeneous catalyst. The heterogeneous transesterification process was studied using design of experiment (DOE), specifically response surface methodology (RSM) based on a four‐variable central composite design (CCD) with α = 2. The transesterification process variables were reaction temperature, x1 (50–190 °C), reaction period, x2 (60–300 min), methanol/oil ratio, x3 (4–12 mol mol–1) and the amount of catalyst, x4 (1–5 wt %). It was found that the conversion of palm oil to biodiesel can reach up to 78.7 % using the following reaction conditions: reaction temperature of 155 °C, reaction period of 120 min, ratio of methanol/oil at 10:1 mol mol–1 and amount of catalyst at 4 wt %. From this study, it was shown that montmorillonite KSF catalyst can be used as a solid catalyst for biodiesel production from palm oil.

Preparation and characterization of chitosan/KSF biocomposite film

AbstractChitosan–clay biocomposites have been prepared in which KSF‐montmorillonite (KSF) is used as filler and diluted acetic acid is used as solvent for dissolving and dispersing chitosan and montmorillonite, respectively. The effect of KSF loadings in biocomposites has been investigated. The characterization with different methods (FTIR, DSC, TGA, SEM, and XRD) on chitosan/KSF biocomposites systems was examined. Morphology and properties of chitosan biocomposites have been studied compared with those of pure chitosan. The FTIR and SEM results indicated the formation of an intercalated‐and‐exfoliated structure at low KSF content and an intercalated‐and‐flocculated structure at high KSF content. The thermal stability and the mechanical properties of the composites were also examined by DSC, TGA/DTG, and tensile strength measurements, respectively. The dispersed clay improves the thermal stability of the matrix systematically with the increase of clay loading. Tensile strength of a chitosan film was enhanced until the clay ratio up to 2 wt% and elongation‐at break decreased with addition of clay into the chitosan matrix. The XRD results confirmed the intercalation of the biopolymer in the clay interlayer by the decrease of 2θ values while the chitosan–clayratio increases. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers