Band 8, Heft 1

Crude dimer acid (DA) was prepared with soybean oil (SO) used as raw material and organic montmorillonite as a catalyst. Fourier transform infrared (FTIR) spectroscopy, hydrogen nuclear magnetic resonance ( 1 H-NMR) and gel permeation chromatography (GPC) were used to characterize the structure of DA. It was demonstrated that the synthesis of crude DA using SO was feasible. A molecular weight of 995–1304 g/mol was obtained by GPC measurement. Then, a type of polyester was synthesized using the crude DA and polyethylene glycol. The effects of reaction temperatures and different catalysts on the conversion rate were explored. The results showed that the esterification conversion rate was improved to 83.13% when SnCl 2 was used as the catalyst, with a reaction temperature of 180°C The FTIR, 1 H-NMR, GPC and TGA were used to characterize the structure and performance of this polyester. The polyester had a molecular weight ranging from 8259 to 10892 g/mol. In addition, its biodegradable behavior was analyzed by the soil burial test and was compared with that of terephthalic acid. The results showed that the composites prepared from DA had a pronounced effect on weight loss during biodegradation.

The factors that influence microwave-assisted biodiesel production reactions have been analyzed in this investigation. The studied parameters included microwave (MW) power, irradiation time, and reactor pressure. The response surface method was used to optimize the reaction conditions. The conversion for the 6:1 methanol/oil molar ratio and 1% catalyst ranged from 68.4% to 96.71%. The optimized conditions were found to be 138 s of MW irradiation at 780 W and 7 bar pressure. The conversion at this point was 97.82%. Biodiesel yield increased at higher radiation times (90–130 s) and pressures (5–7 bar). Results show that MW power and irradiation time have significant effects at the 1% level, whereas pressure had significant effects at the 5% level on biodiesel production in this range. The major properties of the palm oil biodiesel produced herein have met the requirements of the EN 14214 methyl ester standard.

Influence of the process parameters for the industrially relevant reaction of free fatty acid (FFA) with glycerol is investigated. Furthermore, several drying techniques are investigated and a novel method is suggested that can provide more realistic experimental conditions. Silica as an absorbent is found to be a more suitable method for water removal than distillation or carrier gas. Using response surface methodology, important parameters are identified and optimal conditions found. Empirical correlation is developed to account for the most important parameters. Both oil:glycerol ratio and temperature have optimal values for which the highest conversion can be achieved. Interestingly, the highest conversion can be obtained at 220°C; above this temperature the conversion decreases. It is found that the influence of oil:glycerol ratio also exhibits anomalous behavior, where conversion is constant and decreases above a certain value. At optimal conditions, the FFA is reduced to 1.6% from the initial 8.6%.

Green synthesis methods are considered as a safer alternative to the conventional synthetic processes due to their eco-friendly nature, cost-effectiveness, and easy handling. In the present study, an eco-friendly and sustainable method for the synthesis of stable arenediazonium has been developed using saccharin as a cheap and mild acidic agent and tert -butyl nitrite as a diazotization reagent for the first time. These stable intermediates were used in the azo coupling reaction with 4-hydroxybenzaldehyde via telescoped dediazotization. The current method has advantages such as reduced waste by avoiding solvent for the purification of intermediate in diazotization step, cost-effectiveness, simple experimental procedure, good yield of azo dyes, metal-free waste, and environmentally benign conditions. An interesting aspect of this study is the recovery of saccharin from the reaction, which could be reused.

Polyethylene glycol stearate is widely used in pharmaceuticals and cosmetic industries. The current work describes the synthesis and optimization of polyethylene glycol stearate by esterification of polyethylene glycol 600 and stearic acid using Fermase CALB ex 10000, a commercial immobilized lipase B in a solvent-free system. The impact of various parameters that include temperature, reaction time, biocatalyst loading, agitation, acid to alcohol molar ratio, and amount of molecular sieves was optimized to achieve maximum conversion. The highest conversion of 86.98% was obtained in 6 h under the following optimized conditions: temperature 70°C, biocatalyst loading 0.5%, acid to alcohol molar ratio 1:4, speed of agitation 300 rpm, and molecular sieves 5% (w/w). The final condensate product was analyzed through Fourier transform infrared spectroscopy to confirm the functional group and also by 1 H nuclear magnetic resonance spectroscopy. The immobilized catalyst can be reused up to four cycles, exhibiting more than 60% of its initial activity.

In this report, aqueous phase green synthesis of iron oxide nanoparticle utilizing Platanus orientalis is elucidated for the first time. The phytoconstituents of the P. orientalis leaf extract serve a dual role as reducing and capping agent during the fabrication of iron oxide nanoparticles. The role of the leaf extract in the synthesis of iron oxide has been briefly demonstrated in this work. The tailored iron oxide particles were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis, infrared spectroscopy, ultraviolet-visible spectroscopy, and dynamic light scattering technique. Nonetheless, X-ray diffraction pattern reveals the mixed phase nature of the ensuing iron oxide, i.e. α-Fe 2 O 3 and γ-Fe 2 O 3 . The spherical oxide particles have an average diameter of 38 nm as determined from transmission electron microscopy. Infrared spectroscopy results confirmed the stabilization of iron oxide nanoparticles by the phytochemicals present in the leaf extract. Iron oxide nanoparticles show significant antifungal activity against Aspergillus niger and Mucor piriformis , employed as model fungi, but found to be more active toward M . piriformis .

The ultrasound assisted chemical activation of peanut husk using phosphoric acid was studied at a frequency of 20 kHz. Experiments were carried out for the activation of peanut husk in presence of ultrasound followed by the study of consequent effect on the adsorption behavior of copper. Effect of sonication during chemical activation on copper adsorption was studied with respect to various parameters such phosphoric acid concentration, acid impregnation ratio, temperature, duty cycle, sonication time, power and the probe height dipped in the adsorbent-acid slurry. Results showed that after the application of ultrasound during the activation process, copper uptake capacity of the adsorbent is improved with increasing ultrasound power and the activation process is more feasible at 30°C. The copper uptake after activation treatment of 5 min in the presence of ultrasound was found to be 19.6 mg/g as against 17.8 mg/g by conventional chemical activation method performed for 20 min. Thus, after acid treatment in the presence of ultrasound, the adsorbent shows a good adsorption capacity at lower time of chemical activation.

The preparation of magnetic solid adsorbents for solid phase extraction often involved time-consuming stepwise reaction and high-temperature reaction. In this study, the coating of silica and the functionalization of magnetite were performed in a single step at room temperature. The prepared solid adsorbent was phenyl functionalized magnetic adsorbent (Fe 3 O 4 @SiO 2 -Ph). The Fe 3 O 4 @SiO 2 -Ph was used for the determination of phthalates (butyl phthalate, butyl benzyl phthalate, di-ethylhexyl phthalate and di-n-octyl phthalate) in water. Under optimized conditions, this developed magnetic solid phase extraction method achieved the pre-concentration factor of 100, low method detection limit (0.62–1.02 μg/l) and limit of quantitation (1.98–3.25 μg/l), wide linear dynamic range (0.5–100 μg/l) with good coefficient of determination (>0.9980) and good repeatability (relative standard deviation <5%) during the extraction of the selected phthalates. The developed method was also successfully applied to analyze drinking water, mineral water and lake water with good extraction efficiency (70%–102%) and a high degree of precision (≤5%).

Saponin as a biosurfactant was extracted from Iranian Ziziphus spina-christi leaves using three green extraction methods namely, autoclave, microwave and Bain-Marie heating methods. In this study, three solvents namely, methanol, ethanol and water were used to extract saponin. The results revealed that water, as compared to the methanol and ethanol, is a more suitable solvent to extract saponin from the Z. spina-christi leaves. The obtained results indicated that saponin extraction using autoclave provided more suitable physico-chemical properties along with a better yield. In fact, maximum foam volume (12.56 cm 3 ), color intensity (3.24% absorbance unit [a.u.]) and turbidity (1.39% a.u.) of the extracted solutions was obtained by the autoclave heating method. The high performance liquid chromatography (HPLC) results also illustrated that the amounts of extracted saponin using autoclave, Bain-Marie and microwave heating extraction methods were 14, 8.8 and 1.3 (intensity mV), respectively. The results obtained by HPLC were reconfirmed by Fourier transform infrared (FT-IR) analysis.

Highly effective tungsten-based carbon nanotubes (W/CNT) were synthesized and used as a heterogeneous catalyst for the oxidation of dibenzothiophene (DBT) with the oxidant H 2 O 2 . The obtained materials were characterized by modern methods. The Langmuir–Hinshelwood kinetics model described the precursor mechanism of the reaction well through an intermediate compound. The low activation energy showed that the reaction was mainly controlled by diffusion. The positive activation enthalpy proved the endothermic nature of the activation process, and this process did not alter the inside structure of the catalyst. The thermodynamic parameters of the reaction were determined, which implied that the oxidation was endothermic and spontaneous at 303 K. The more negative values of the Gibbs free energy from 283 to 323 K confirmed that the reaction was more favorable at high temperatures. The stability and activity of catalyst were retained after three reaction cycles.

Calcined sodium silicate could serve as an efficient and benign heterogeneous catalyst for the production of L-α-glycerophosphocholine from natural lecithin. The catalytic transesterification of natural lecithin by calcined sodium silicate proceeded to almost 100% conversion under the following conditions: sodium silicate amount of 6 wt%, reaction temperature of 65°C, lecithin concentration of 10.5 mmol/l, stirring intensity of 300 rpm, reaction time of 120 min. In addition, this catalyst could be separated completely by simple centrifugation and retained high activity after three re-uses. Compared to the previously reported catalysts, calcined sodium silicate, with the significantly important characteristics of non-toxicity and easy excretion from the human body, was beneficial to the benign production of L-α-glycerophosphocholine and its security as well as application in food and medicine fields.

A series of Keggin heteropolytungstate salts (M 1.5 PW 12 O 40 , M=Cu, Co, Zn and Fe) were prepared and characterized utilizing inductively coupled plasma spectrometry (ICP), Fourier transform infrared (FTIR) spectra, and ultraviolet-visible (UV-Vis) light spectroscopy. The as-prepared catalysts were tested for the oxidation of ethylbenzene by using carbon dioxide/hydrogen peroxide (CO 2 /H 2 O 2 ) as the oxidizing agent system under solvent-free conditions. The results indicated that the heteropolytungstates catalyzed the side chain oxidation of ethylbenzene leading to acetophenone as a major product. The effect of various reaction parameters on ethylbenzene oxidation over the best catalyst of the series, namely Co 1.5 PW 12 O 40 loaded on activated carbon (AC), was investigated. It was found that the selectivity depends strongly on the reaction temperature. Higher reaction temperatures reduce the conversion due to the decomposition of H 2 O 2 . Oxidation by a large amount of H 2 O 2 decreases the conversion owing to a decrease of the solubility of ethylbenzene in an aqueous medium, and favors the oxidation of the reaction products, which are more soluble in an aqueous medium. The increase of the CO 2 pressure improves both the conversion and the selectivity of acetophenone due to the involvement of the percarbonate species (HCO 4 − ) responsible for oxidation by oxygen transfer.

The hydrocyanation of 2-arylmethyleneindan-1,3-diones with potassium hexacyanoferrate(II) as a nontoxic cyanating agent to synthesize 2-(1,3-dioxoindan-2-yl)-2-arylacetonitriles in the presence of benzoyl chloride as a promoter and potassium carbonate as a base by a one-pot procedure is described. The use of nontoxic and inexpensive cyanide source, high yield and simple workup procedures are the advantages of this protocol.

This report presents a study of synthesis of hydratropic aldehyde from α-methylstyrene employing Al 2 O 3 -supported metal phthalocyanines as catalyst, molecular oxygen as oxidant and isobutyraldehyde as co-oxidant. The catalytic system was applied in the synthesis of hydratropic aldehyde for the first time. Under optimal conditions, the conversion of α-methylstyrene reached 99%, whereas the selectivity of hydratropic aldehyde reached 85.14%. Possible reaction mechanism and the effects of different factors on oxidation reaction were investigated. Aluminum oxide-supported metal (M = Co, Ni, and Fe) phthalocyanine catalysts (MPc/Al 2 O 3 ) were prepared using the “ship-in-a-bottle” method by synthesizing metallophthalocyanines in support holes. Obtained catalysts were characterized by N 2 adsorption, Brunauer-Emmett-Teller surface area (BET), inductively-coupled plasma atomic emission spectrometry (ICP-AES), IR, UV-Visible (UV-Vis), and X-ray diffraction (XRD).

Polycarbonate (PC) wastes, including optical discs (CDs) and digital optical discs (DVDs), were chemically recycled into valuable materials such as 4,4′-(propane-2,2-diyl)diphenol (BPA) and etherified derivatives of BPA using sodium hydroxide (NaOH) as the alkali metal catalyst and nanostructured titanium dioxide (nano-TiO 2 ) and microstructured titanium dioxide (micro-TiO 2 ) as the solid supports in the binary green system consisting of water and 2,2′-oxydi(ethan-1-ol) (DEG) under conventional heating method, and data were compared. In this study, the effects of various parameters, such as solvent composition, concentration of NaOH, and solid support, were studied on the reaction progress. In these reactions, the importance of water as the green solvent was investigated in achieving pure BPA as the valuable material. When used with 20% aqueous DEG (pbw), a pure BPA can be obtained at 70% yield in the presence of nano-TiO 2 and micro-TiO 2 as the solid supports. According to the results, the use of nano-TiO 2 in comparison with micro-TiO 2 accelerates the chemical recycling of PC wastes. The nano-TiO 2 catalyst recovery shows that the recovered solid support is applicable for four cycles. The obtained products were characterized using spectroscopic methods, namely, 1 H NMR, 13 C NMR, and Fourier transform infrared spectroscopy as well as gas chromatography-mass spectrometry.

The aim of the presented work was to assess the potential of Medicago polymorpha extract to synthesize silver nanoparticles (AgNPs) as a green method. It was a simple one-step synthesis approach and the product obtained was characterized by UV-visible spectroscopy, Fourier transform infrared (FTIR), powder X-ray diffraction, thermogravimetric analysis, and field-emission scanning electron microscopy (FE-SEM). At room temperature, the optimum time for the completion of the reaction (i.e. the formation colloidal solution) was just 5 min. FE-SEM images showed that AgNPs were predominantly in spheres, whereas FTIR spectrum analysis inferred that gallic acid present in the extract initially reduced silver ions to elemental silver. The carboxylic and hydroxyl groups of biomolecules present in the extract stabilized AgNPs by passivating the surface to prevent aggregation, resulting in uniform distribution. The antibacterial activity of synthesized AgNPs showed effective inhibitory effects against waterborne pathogens, including Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ), at a minimum inhibitory concentration of 10 μg/ml. Membrane permeability and respiration studies were also performed to assess the surface role of the synthesized AgNPs. The prepared AgNPs exhibited excellent antioxidant activity and catalytic reduction of methyl orange with a rate constant of 6.8×10 −3 s −1 .

A series of active and selective MCM-41 supported catalysts have been successfully prepared and used for bioderived glycerol esterification with acetic acid to produce fuel additives. In the synthesis of MCM-41, an acidic hydrothermal synthesis route was used, and silicotungstic acid (STA) and zirconia (ZrO 2 ) were added to the catalyst structure by wet impregnation. X-ray diffraction, nitrogen adsorption-desorption methods, scanning electron microscopy with energy-dispersive spectroscopy, and inductively coupled plasma-mass spectrometry analysis were used for characterizations of the catalysts. Diffuse reflectance infrared Fourier transform spectroscopy analyses of pyridine-adsorbed catalysts owns Lewis and Brønsted acidity hosting in one, which promotes the esterification reaction of glycerol into glycerol esters with high selectivity. Esterification of glycerol reactions were performed at temperature intervals of 105°C–200°C, with an amount of catalyst equal to 0.5 g, and glycerol/acetic acid molar ratio of 1:6 in a stirred autoclave reactor operated batchwise. STA and ZrO 2 -impregnated MCM-41 catalysts showed better performance with a complete glycerol conversion and high selectivity to triacetin.

In this study, plant-mediated copper nanoparticles (CuNPs) were synthesized. Due to its direct synthesis mechanism and eco-friendly nature, the current method accounts for the green chemistry approach using the fruit extract of Duranta erecta for the first time. The UV-visible spectrum of the CuNPs solution showed a distinct absorption peak at 588 nm. Fourier transform infrared spectroscopy confirmed that the fruit extract is responsible for the reduction as well as the stabilization of CuNPs. X-ray diffraction patterns conform the crystalline nature of CuNPs. Energy-dispersive X-ray spectroscopy was performed for elemental analysis whereas field emission scanning electron microscopy was carried out for surface morphology. Prepared CuNPs were used for the reduction of carcinogenic azo dyes methyl orange (MO) and congo red (CR). CuNPs exhibit outstanding catalytic reduction for MO and CR in the presence of NaBH 4 as reducing agents with the pseudo-first-order rate constants of 8.6×10 −3 s −1 and 5.07×10 −3 s −1 for MO and CR, respectively. Thus, natural plant materials act as cheap and environmentally friendly support for the synthesis of CuNPs and could be used for the purification of water from organic dye effluents.

Biologically synthesized nanoparticles are gaining importance as they offer several advantages, such as the ease with which they can be scaled up, the cost-effectiveness of the process and the green route of production. In this study, silver (Ag) nanoparticles were biosynthesized using the cellular extract of Penicillium oxalicum GRS-1 and then characterized by ultraviolet visible spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. The biosynthesis of nanoparticles was optimized by following the one factor at a time approach, wherein the temperature of 60°C, pH 7.0 and 1.5 m m silver nitrate (AgNO 3 ) concentration were found to be most favorable factors for the production of Ag nanoparticles. Upon statistical optimization, the maximum production of Ag nanoparticles with a concentration of 136 ppm was achieved at pH 7.2, AgNO 3 concentration 1.975 m m and 86 h using the crude cellular extract of P. oxalicum GRS-1 having nitrate reductase activity. TEM analysis showed that the Ag nanoparticles were spherical in shape with sizes ranging from 10 to 40 nm. The biosynthesized nanoparticles showed strong antimicrobial activity against the common food-borne, pathogens including Staphylococcus aureus , Escherichia coli and Salmonella typhimurium with respective minimum bactericidal concentrations of 32, 16 and 32 μg/ml.

The present study focuses on the overproduction of bioethanol through submerged fermentation. In a batch-scale submerged bioreactor using a traditional and an industrial Saccharomyces cerevisiae (NCYC 4109 and SFO6) strains, the fermentation was accomplished. The effects of the substrate brix (20.50–24.00 °Bx) and inoculum percentage in the initial fermentation solution (15%–45%) as independent variables on bioethanol production (g/l) as the dependent variable were assessed using the response surface methodology. Using the obtained experimental values for the response variable based on experiments for the fermentation parameters, a general model (second-order) with high coefficient of determination values ( R 2 > 95%) was generated to predict the bioethanol concentrations that were obtained using both yeast strains. The obtained results indicated that the optimum fermentation conditions to overproduce bioethanol (56.14 g/l) using the SFO6 yeast were at the substrate brix and inoculum percentage values of 24.70 °Bx and 26.35%, respectively. However, a higher concentration of bioethanol (53.1 g/l) using the NCYC 4109 yeast strain was obtained at the substrate brix and inoculum percentage values of 24.68 °Bx and 40.07%, respectively.

In traditional large-scale industrial applications of solvent extraction, there are some limitations such as low extraction efficiency, emulsification, co-extraction, and potential safety hazards. Recently, the application of microfluidic technology in solvent extraction has been dedicated to avoid the above problems effectively. However, manufacturing microchannels becomes a key problem before the application of such a new technology. In this article, the design and fabrication of a “Y”-shaped microreactor by using a three-dimensional (3D) printer, and its feasibility for extraction and separation, is illustrated. The extraction performance of a “Y”-shaped microreactor was investigated by carrying out the extraction of In 3+ and Fe 3+ from a sulfate solution under different experimental conditions. When the residence time was 210 s, the volume fraction of extractant (D2EHPA) was 30%, and the initial pH value of the aqueous solution was 0.7, the extraction rate of In 3+ and the separation coefficient β In/Fe were 98.07% and 1593, respectively. Remarkably, the handling capacity of the 3D-printed “Y” microreactor presented in this work with a channel length of 36 mm was superior, whereas the extraction rate of In 3+ was very close to that of the previously reported microchip with a channel length of 120 mm.

A green, biomimetic, and one-pot synthesis of silver-doped zinc oxide (ZnO:Ag) nanoparticles via hydrothermal route utilizing Prunus cerasifera leaf extract has been reported for the first time. Synthetic route involved optimization for leaf extract. Doped nanoparticles were characterized for crystalline, optical, compositional, and morphological makeup via X-ray diffraction (XRD), ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. Direct energy bandgap was calculated through Tauc plot. The incorporation of Ag + into Zn 2+ sites within ZnO crystal was obtained using leaf extract as a reducing agent. Ag inculcated positional modifications in ZnO structure confirmed via XRD-shifted peaks. Ag:ZnO nanoparticles were found to be an efficient nanophotocatalyst against bromocresol green and bromophenol blue ( R 2 =0.83 and 0.95, respectively) in direct solar irradiance. Degradation efficiencies up to 86% and 95% in less than 15min were achieved. Furthermore, the synthesized doped nanoparticles expressed highly active to active zones of inhibition against nine microbes of pathogenic nature toward human and crops. Doped nanoparticles inhibitory activity was found to exceed standard antibiotic drugs ampicillin and amphotericin B in a standard Kirby-Bauer disc diffusion assay. Creditable photocatalytic and antimicrobial activities of synthesized doped nanoparticles signify their prospects in commercialization into nanophotocatalyst and bactericidal/fungicidal agent at industrial scale.

In this paper, we investigated the effect of temperature, glycerol etherification concentration with benzaldehyde, organic solvent and catalyst reuse effects using a cationic acidic resin as catalyst for production of green cyclic acetals of high commercial value. The best reaction conditions show a conversion above 93% of glycerol and yield to cyclic acetals above 61%. The highest selectivity elements observed were 2-phenyl-1,3-dioxan-5-ol, in cis and trans isomer forms reaching 80%. The temperature had a positive effect increasing on glycerol conversion, though it also favored the formation of undesired compounds. A high concentration of benzaldehyde reactant kept the selectivity values constant but increased glycerol conversion resulting in higher yields, mainly when organic solvents were used. Reuse of the catalyst resulted in a slight decrease in yield values, which demonstrated stability and durability of the catalyst used.

The present study focuses on the biogenic synthesis of selenium nanoparticles (Se NPs) using Pelargonium zonale leaf extract under microwave irradiation. Response surface methodology was used to evaluate the effects of the synthesis parameters, namely amounts of the leaf extract (0.5–2.5 ml) and amounts of the 10 m m sodium selenite solutions (15–65 ml), at constant microwave heating (4 min), on the concentration and particle size of the fabricated Se NPs, optimize the synthesis conditions and verify the generated models and the procedures. The obtained results indicated that Se NPs with preferable attributes of mean particle size (50 nm), zeta potential (−24.6 mV), absorbance [34.6% absorbance units (a.u.)] and broad absorption peak (319 nm) were formed at the optimum synthesis conditions including amounts of 1.48 ml and 15 ml Pelargonium leaf extract and sodium selenite solution, respectively. The antibacterial activities of the synthesized Se NPs against Escherichia coli and Staphylococcus aureus indicated that the created NPs had higher antibacterial activities toward the Gram-positive bacteria. Furthermore, the synthesized Se NPs indicated higher antifungal activities against Colletotrichum coccodes and Penicillium digitatum .

In the present study, high surface area amorphous magnesia was synthesized using walnut shell as a template. This green, simple and useful synthetic protocol was based on the precipitation of magnesium nitrate on biomass in an aqueous phase, followed by calcination. Materials were characterized using X-ray diffraction, scanning electron microscopy (SEM) and N 2 adsorption/desorption porosimetry, and the results exhibited high surface area for magnesium oxide. Furthermore, the pore size and surface area of these mesoporous materials can be adjusted by varying the biomass/magnesium nitrate ratio. In addition, magnesium oxide was studied as the support of palladium nanoparticles for the aerobic oxidation of alcohols. We have found out that the resulting Pd-loaded material acts as an effective catalytic system for the aerobic oxidation of benzylic and aliphatic alcohols. The catalyst can be recovered and reused three times without loss of activity. Also, to test the catalytic activity of magnesium oxides as a solid catalyst, we selected Meerwein-Ponndorf-Verley reduction of cyclohexanone with 2-propanol over different magnesium oxides.

We report the effect of various parameters, namely substrate concentration, time, pH and temperature, on the biosynthesis of silver nanoparticles (AgNPs) by using the extract of actinobacterial strains, which were isolated from the sediments of Lonar Crater Lake in India. It was found that the formation of AgNPs and its morphology depended on synthesis conditions. Visual observation of the reaction mixture, ultraviolet-vis spectroscopic analysis and mass of synthesized AgNPs indicated that 25°C, pH 7 and 3 days of incubation time were optimal for its efficient synthesis. The transmission electron microscopy (TEM) analysis revealed aggregation and irregular shape of AgNPs both at acidic pH and below 25°C. It was found that alkaline pH and temperature higher than optimal fostered the formation of nanoparticle aggregates. Based on the obtained results, it was concluded that the efficiency of biological synthesis by using actinobacteria as well as the size and shape of fabricated nanoparticles can be manipulated by controlled conditions of synthesis process. The use of desired nanoparticles increases its potential for medical applications.

The present study aimed for the extraction of color dyes from different sources, such as Brassica oleracea , Brassica campestris , Citrus limon , Citrus limetta , Tagetes erecta , Spinacea oleracea , Beta vulgaris , Rosa indica and Curcuma longa. The leftovers of such plants were mainly used for color dye extraction and their confirmation using spectrophotometric analysis. The specific color pigments like carotenoids, anthocyanin, chlorophyll and betanin were found to be the main coloring agents that impart specific color to the samples. Among all these samples, the maximum yield was obtained from C. limetta aqueous peel extract, and among all the temperatures employed room temperature was found out to be the most suitable temperature for the stability of color extracts. The extracted colors were utilized in candy making and sugar syrup making and were also used for coloring various foods stuffs. Moreover, the extracted color dyes were applied for dyeing purposes on cotton cloth with alum showing better and more enhancing color fastness results than the lime.

A mechano-chemical reaction formed by a simple high-energy ball milling was applied to simulate the synthesis of ammonia and organic precursors from common inorganic materials that occurred on early Earth. By milling for 0.5–64 h at centrifugal accelerations of 20–150 G, ammonia and acetic acid were produced from inorganic materials, such as iron nitride, nitrate, carbide, and carbonates, in water. The experimental results can offer waste processing of metallic acids by the mechanical method without using any alkaline sources and suggest that the high-energy milling technology provides a new synthesis mode to form wide ranges of organic materials and scope for broader applications. This study also offers a new route to the formation of the precursors on early Earth and proposes that tremors and friction initiate micro-impacts between rocks and sand in the terrestrial crust, resulting in the formation of ammonia and organic materials from inorganic materials.

Novel N 1-substituted 3,4-dihydropyrimidin-2(1 H )-one derivatives were synthesized through Biginelli condensation of aromatic aldehydes, β -ketoesters, and monosubstituted (thio)ureas in the presence of copper methanesulfonate at 90°C under solvent-free conditions. The screening of the catalysts showed the copper methanesulfonate was the best. Its catalytic activity remained after three times of use. The products were characterized by IR, 1 H NMR, 13 C NMR, elemental analysis, and X-ray single crystal diffraction technique. A reasonable reaction mechanism was proposed.

Biodiesel is a fuel from vegetable oil or animal fat, and is a promising substitute for petroleum-derived diesel. Transesterification is the most widely used method in biodiesel production. Eggshell is rich in calcium carbonate (CaCO 3 ), and when it is subjected to heat treatment it results in calcium oxide (CaO). CaO from eggshells was prepared at different calcination temperatures, and characterized by X-ray diffraction, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The obtained CaO was used as a catalyst. All catalysts showed good stability and excellent morphology for biodiesel synthesis. Catalytic activity was evaluated by the methyl transesterification reaction of cotton oil for 3 h, 9:1 methanol:oil molar ratio, 3 wt% (catalyst/oil weight ratio) catalyst and 60°C. Biodiesels showed an ester content of 97.83%, 97.23% and 98.08%, obtained from calcined eggshell at 800°C, 900°C and 1000°C, respectively. Biodiesel quality was affected by the acidity of the cation exchange resin. The kinematic viscosity of biodiesel was in accordance with specification, except for the biodiesel obtained from the calcined catalyst at 1000°C. The CaO from eggshells obtained at different calcination temperatures is promising for biodiesel synthesis.

Large amounts of spent mercury catalyst (SMC) produced in producing polyvinyl chloride (PVC) has a great influence on the environment. In this work, microwave and ultrasonic spray were applied to regenerate the carrier of SMC. The optimal experimental conditions were the regeneration temperature of 900°C and regeneration time of 60 min. Subsequently, the textures of pores and mercury content, morphology structure and surface functional groups of SMC and the regenerated activated carbon (RAC) were characterized by N 2 adsorption and desorption isotherms, ICP, SEM, EDS and FTIR. Additionally, the adsorption behaviors of RAC on methylene orange (MO) and congo red (CR) were explored to study the mechanisms. The results of kinetics and isotherm showed that experimental data were fitted well with the pseudo second-order and Langmuir isotherm model, respectively. The maximum adsorptions of MO and CR were 529 and 301 mg/g at 323 K. The thermodynamic results illustrated that the adsorption MO and CR onto RAC was spontaneous and endothermic. The results demonstrated that RAC prepared from SMC by microwave heating and ultrasonic spray could realize the comprehensive utilization of waste resources.

The leaves extract of Fraxinus chinensis Roxb was used for the synthesis of the innovative phytogenic magnetic nanoparticles (PMNPs) without adding toxic surfactants. The formation, morphology, elemental composition, size, thermal stability, structure and magnetic properties of these PMNPs were examined by UV-visible spectrophotometry, FT-IR, XRD, SEM, EDX, TEM, VSM, XPS, BET and TGA. The reactivity of the obtained PMNPs against decolourising toxic dyes, namely, malachite green (MG), crystal violet (CV) and methylene blue (MB), were investigated by UV-vis spectrophotometry. Further, the factors affecting the removal of dyes, including solution pH, adsorbent dosages, initial concentration of dyes, reaction temperature and contact time, were also investigated. The results revealed the decolourisation of 99.12% of MG and 98.23% of CV within 60 min, and 97.52% of MB within 200 min by the PMNPs using dyes concentration of 25 mg/l at pH 6.5 and 298.15 K. The kinetics outcome indicated that the degradation of dyes matched well to the pseudo first-order reaction kinetics model. Furthermore, the probable degradation mechanism of dyes by the PMNPs, including the adsorption of cationic dye molecules onto the negatively charged surface of adsorbent and the oxidation of the Fe° in the solution, were discussed. Thus, the PMNPs can be produced by the bulk and have great potential to be employed for biomedical/environmental remediation.

Synthesis of nanoparticles (NPs) using plant extracts has been suggested as an environmentally friendly alternative to chemical synthesis of semiconductor NPs. In the present study, ZnO NPs were synthesized by a simple and cost-effective method using Coriandrum sativum leaf extract and zinc acetate as precursors. The as-synthesized ZnO NPs were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) analysis. The results confirmed the formation of ZnO NPs with a wurtzite structure, spherical shape and average particle size of 24 nm. The photocatalytic degradation of reactive yellow 186 (RY 186) dye was carried out under direct sunlight irradiation and its degradation efficiency and apparent rate constant (K’ app ) of reaction were calculated to be 93.38%, and 0.0019 min −1 , respectively. The optical band gap value of the as-synthesized ZnO NPs was found to be 3.4 eV, which indicates the presence of blueshift. Owing to the presence of blueshift and a wide band gap of synthesized biogenic ZnO NPs, the overall absorption of sunlight irradiation will be enhanced, which leads to higher degradation efficiency of the dye. The current study thus highlights the optical band gap properties of biogenic ZnO NPs and their significance as a heterogeneous catalyst for the purification of polluted water.

During biosorption, the biosorbent releases many organic compounds to the medium. In the present study, extracts of pomegranate peel (PP), green coconut shell (GCS), and karuvelam wood (KW) were prepared at three different conditions, namely 12 h, 3 h, and 3 h at pH 2, for the removal of hexavalent chromium [Cr(VI)]. The amount of organic compounds, mainly the leached organic compounds in the extract before and after treatment with Cr(VI) solution, was determined by chemical oxygen demand analysis. The total phenolic content, antioxidant activity, and total flavonoid content were used to estimate the chromium reduction potential of the extracts. The PP extract is the richest in all the three factors, followed by GCS and KW. The disappearance rate of Cr(VI) in the presence of PP extract reached 99.63% for the 50 mg/l concentration within 3 min, while it was 12% and 10% for GCS and KW, respectively, for the same concentration and time. Reaction mechanisms were formulated with the help of Fourier transform infrared spectroscopy to confirm the role of leached compounds from natural materials for the removal of heavy metal.

Molecular weight reduction of natural rubber (NR) with hydrogen peroxide (H 2 O 2 ) oxidizing agent is limited in biphasic water-toluene systems that is attributed to mass transfer. In this work, CO 2 was applied to the (aqueous H 2 O 2 )-(toluene-NR) systems with the objective of improving reaction efficiency. Experiments were performed on the reaction system with CO 2 at 12 MPa and at reaction temperatures and times of 60°C–80°C and 1 h–10 h to evaluate the reaction kinetics. CO 2 could enhance the NR molecular weight reduction by lowering the activation energy (from 121 kJ·mol −1 to 38 kJ·mol −1 ). The role of CO 2 in the reaction system seems to be the formation of oxidative peroxycarbonic acid intermediate and promotion of mass transport due to the reduction in the toluene-NR viscosity and interfacial tension. The epoxidized liquid NRs ( M ̅ n =4.9×10 3 g·mol −1 ) obtained from NR molecular weight reduction was further processed to prepare hydroxyl telechelic NR ( M ̅ n =1.0×10 3 g·mol −1 ) and biobased polyurethane.

A highly efficient multi-component one-pot synthesis of novel 1 H -imidazo[1,2- a ]imidazole-3-amine and imidazo[2,1- c ][1,2,4]triazole-5-amine derivatives has been developed through the reaction of easily available aromatic aldehydes, benzoyl cyanide and either 2-aminoimidazole-4,5-dicarbonitrile or 3-amino-1,2,4-triazole in pyridine under controlled microwave heating. The process is environmentally friendly, is operationally simple, with short reaction time and with high yields.

Zinc oxide nanoparticles (ZnO NPs) were green synthesized using Pelargonum zonale leaf extract under three different heating methods, and their characteristics were evaluated using X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay and antibacterial well diffusion method. The FT-IR analysis indicated that the Pelargonium leaf extract contained hydroxyl and amide I groups which were related to the proteins, carbohydrate, tannins and phenolic compounds of the extract and had an essential role in the reduction of the zinc ions and synthesis of the ZnO NPs. The obtained results revealed that the synthesized spherical individual ZnO NPs as well as the number of aggregates using microwave irradiation, autoclave and conventional heating (heater-stirrer) methods had average crystalline size of 51, 60 and 61 nm. Furthermore, antioxidant activities of the fabricated ZnO NPs were 7.8, 4.1 and 5.5% by using conventional heating, autoclave and microwave irradiation, respectively. The obtained results indicated that all the formed ZnO NPs had bactericidal effects against to the both Gram negative and Gram positive bacteria strains. However, the synthesized ZnO NPs using conventional heating method had the highest antibacterial activities toward both studied bacteria strains.

Plant-based materials are reported to have a wide range of applications in the environmental and biomedical sectors. In this report, we present an economic and environmentally friendly supported turmeric powder (TP) biomass for the support of Ag, Ni and Cu nanoparticles (NPs) designated as Ag@TP, Ni@TP and Cu@TP. The in situ syntheses of the stated NPs were achieved in aqueous medium using NaBH 4 as a reducing agent. The prepared NPs were applied for the degradation of o -nitrophenol (ONP), m -nitrophenol (MNP), p -nitrophenol (PNP), methyl orange (MO), Congo red (CR), rhodamine B (RB) and methylene blue (MB). Initially, Ag@TP, Ni@TP and Cu@TP were screened for the MO dye and antibacterial activity, where Ag@TP displayed the strongest catalytic activity for MO and bactericidal activities as compared to Ni@TP and Cu@TP. The quantity of metal ions adsorbed onto the TP was investigated by atomic absorption spectroscopy. The Ag@TP, Ni@TP and Cu@TP were characterized through X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, thermal gravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDS) and field emission scanning electron microscope (FESEM) analysis.

We report a rapid and efficient synthesis protocol for mesalamine via a green approach with 2-chloro-5-nitrobenzoic acid as the starting material, for its large-scale production. This one-pot method involves the conversion of a chloro group into a hydroxyl group using aqueous KOH solution, followed by the reduction of a nitro group to amine using Pd/C. The product was characterised and confirmed by 1 H-nuclear magnetic resonance (NMR), 13 C NMR, IR and mass spectrometry techniques. The salient features of the method include excellent conversion (99.3%), high yield (93%), cost effectiveness and validated results for benign, large-scale production.

This report describes mathematical relationships between step and cumulative process mass intensities (PMIs) for synthesis plans, and analogous parameters applied to E-factors. It is shown that both step E-factors and step PMIs are not additive for synthesis plans. It is also shown that a recursive calculation of cumulative PMIs from step PMIs is a rapid method of determining overall PMIs for synthesis plans, though cumulative PMIs are not sufficiently informative as step PMIs or step E-factors to identify bottlenecks in synthesis plans. Illustrations on the use of these metrics to track the material efficiency of published synthesis plans for the pharmaceutical, apixaban, are given as a template example. Advantages and disadvantages of each metric are discussed. A general algorithm to select the most promising candidate synthesis plans considered at the design stage for a given molecular target that most likely satisfy “green” material efficiency criteria is also presented.

The present study investigates a comparative study of the sorption of Cr 3+ and Cr 6+ from water using an agricultural by-product; mango peels in batch system under the effect of initial metal ion concentrations, solution pH, temperature, sorbent dose and contact time. Characterization of the mango peels was done before and after sorption of Cr 3+ and Cr 6+ using scanning electron microscopy, surface area pore size analyzer and FTIR spectroscopy. The pH study revealed that that maximum removal of Cr 3+ and Cr 6+ was obtained at pH 5.0 and 7.0 respectively. Among various kinetic models, pseudo-2 nd order well explained the data owing to the higher values of R 2 and the nearness between the values of experimental and calculated sorption capacities. The isotherms study revealed that Freundlich is the suitable isotherm for explanation of the equilibrium data due to higher R 2 values. The monolayer sorption capacity of mango peels was found to be 98.039 mg g -1 for Cr 3+ and 66.666 mg g -1 for Cr 6+ . The spontaneity and exothermic nature of the sorption process of Cr 3+ and Cr 6+ using mango peels was reflected from thermodynamic study.

Large amounts of acidic waste are produced on the industrial scale during hydrolysis of partially amorphous cellulose to produce microcrystalline cellulose (MCC). The essential disposal and treatment of this highly acidic liquid wastes the acid feedstock and increases the production cost. To maximize the use of acid without sacrificing the MCC product quality, this project reports a successful attempt to recycle the acid hydrolysis waste liquid, focusing on the impact of waste recycling on MCC morphology and reducing sugar in the hydrolysate. The results showed that when the waste liquid is recycled 1-5 times, no metal accumulation occurred while cellulose particles remained intact, maintaining their shape and size. Their extent of crystallinity remained nearly constant, even increasing slightly with up to three cycles. The concentration of reducing sugar showed growth when recycling the waste liquid up to three times, although not quite to the levels that would allow for its cost-effective fermentation. The acid amount to be added at the start of each cycle was near 50% of that used on the first stage.

Deep eutectic solvents (DESs) exhibit numerous advantages over conventional ones used in several chemical and biochemical processes. Besides addressing most of the principles of green chemistry, DESs can also act as catalyst depending on their nature. The use of DESs as acid catalyst has several advantages such as utilization at stoichiometric amount, non-toxicity, possibility of the recovery, similar or higher catalytic effect than the acid itself alone, the recyclability and reusability without a significant loss of activity. In this mini-review, the state- of-the-art in the use of DESs as catalyst is presented. The DESs, which show Lewis type acidity, Brønsted type acidity and other types of catalytic influence in various types of reactions including esterification, organic synthesis, glycolysis and depolymerisation are presented and their roles in the reactions are discussed.

The energy efficiency of the microwave-assisted synthesis of pyrrolidinones was demonstrated using catalytic loading of 1,1’-butylene-bis(3-sulfo-3 H -imidazol-1-ium) chloride as a sulfonic acid functionalized ionic liquid in ethylene glycol as green solvent. The effect of electron donating and electron withdrawing groups on aniline derivatives was studied under conventional heating and microwave irradiation. Furthermore, the cation effect of ionic liquids containing sulfonic groups on the catalytic efficiency for the synthesis of ethyl-1-phenyl-2-(4-chlorophenyl)-4-hydroxy-5-oxo-2,5-dihydro-1H-pyr-role-3-carboxylate was investigated under conventional heat. The experimental results exhibited that there is a relationship between catalytic efficiency and the number of sulfonic groups and imidazolium moieties linked by carbon spacer.

In this study, Co 3 O 4 and Ag-Co 3 O 4 were synthesized by a novel and green method using leaves extract of Helianthus annuus from cobalt nitrate and silver nitrate. The synthesized particles were characterized using X-ray powder diffraction, thermal gravimetric analyses, scanning electron microscopy, particle size analyses and UV-Visible spectroscopy. The photo catalytic activities of synthesized Co 3 O 4 and Ag-Co 3 O 4 were appraised by degrading methyl orange dye and after 120 minutes of reaction a degradation of 53 and 87% was achieved using 100 mg/L (50 mL) solution of methyl orange and 0.1 g Co 3 O 4 and Ag-Co 3 O 4 as catalyst respectively. This green synthesis of Ag-Co 3 O 4 proves to be an eco-benign, environmental benign, simple and effective approach for degradation of dyes in aqueous medium.

Custom design of JMP software was used to optimize the iodine number of coal-based electrode materials. Taking the additive ratio (A), heating rate (B) and final pyrolysis temperature (C) into account and the significance sequence was C>B>A. Set the additive ratio as 0.2, the heating rate as 5°C/min and the final temperature as 900°C, the iodine number was improved to 403.14 mg·g -1 , and the compressive strength was 2.01 MPa. Surface morphology of the coal-based electrode materials were characterized by scanning electron microscopy (SEM). The functional group species were explored by Fourier infrared spectrophotometer (FTIR). Then applied the voltage of 4 V, coal-based adsorption materials were set as cathodes and anodes in a 3-dimensional electrode system with the commercial activated carbon as a particle electrode. After 5 h treatment for cyanide wastewater, the removal rate of most ions was achieved to 72% or more. It was the collaborative effect in the combined action of electro-adsorption and electrodeposition.

Selenium as an essential trace element for the health of the humans was used to hydrothermally synthesis of selenium nanoparticle (Se NPs) using Aloe vera leaf extract (ALE). Effects of synthesis parameters namely; amount of ALE (1–5 ml) and amount of Na 2 SeO 3 solution (10–30 ml), on the particle size and colour intensity of the solution containing Se NPs were studied using response surface methodology. FT-IR spectroscopy, UV-Vis spectrophotometry, DLS analyzer and TEM were used to determine the specifications of the ALE and synthesized Se NPs. Obtained results indicated that the ALE contained several bioactive compounds, which they had hydroxyl and amide І groups in their structures and these two functional groups had key roles in the reduction of the selenium ions to form Se NPs and stabilizing of them. Furthermore, spherical fabricated Se NPs using obtained optimum synthesis parameters, 4.92 mL of ALE and 13.03 mL of Na 2 SeO 3 solution, had colour intensity, mean particle size, zeta potential and polydispersity index values of 3.0% a.u., 50 nm, -18 mV and 0.344, respectively according to the DLS analysis. The synthesized Se NPs had also high antibacterial and antifungal activities against 4 selected pathogenic bacteria and spoilage fungi strains.

The waste phenolic resin was utilized as the raw material to prepare activated carbon (AC) used KOH as the activating agent via microwave heating. The phenolic resin was carbonized at 500°C and then performed with a KOH/Char ratio of 4 and microwave power of 700 W for a duration of 15 min. The physic-chemical characteristics of the AC were characterized by N 2 adsorption instrument, FTIR, SEM and TEM. The BET surface area and pore volume of AC were found to be 4269 m 2 /g and 2.396 ml/g, respectively. The activation process to generate such a phenomenally high surface area of the AC has little reported in open literatures and could pave way for preparation adsorbents that are far superior to the currently marketed adsorbents. The methylene blue (MB) was used as the model to assess its suitability to dye wastewater treatment. Towards this, the MB adsorption isotherms were conducted at three different temperatures and tested with different adsorption isotherm models. The adsorption isotherms could be modeled using Langmuir isotherm. While the kinetics could be used the pseudo-second order kinetics to describe. Thermodynamic results demonstrated that the adsorption process was a spontaneous, as well as an endothermic.

Industrial cellulosic ethanol production is a challenge due to the high cost of cellulases for hydrolysis when lignocellulosic materials are used as feedstock. In this study, direct ethanol production from cellulose was performed by consortium of Trichoderma reesei and Candida molischiana . Cellulose was hydrolyzed by a fully enzymatic saccharification process using Trichoderma reesei cellulases. The produced reducing sugar was further utilized by Candida molischiana for ethanol production. Because the optimal temperature for the cellulase system is approximately 50°C, the effect of temperature rise from 30°C to 50°C on cellulose hydrolysis was investigated. The results showed that the temperature rise from 30°C to 50°C after 36 h of cultivation was the best for reducing sugar and glucose production. Under these conditions, the maximum concentrations of reducing sugar and glucose produced by T. reesei were 8.0 g/L and 4.6 g/L at 60 h, respectively. The maximum production of ethanol by C. molischiana was 3.0 g/L after 120 h.

Metal oxide nanoporous materials and nanoparticles have main potential uses in several different fields such as nanoelectronics, biomedical science, renewable solar energy, drug-gene delivery, thermal insulation, and so on. On the other hand, it is vital for scientists to understand that agricultural waste biomass-assisted synthesis is less costly, environmentally friendly and renewable strategy, and therefore, agricultural wastes are ideal renewable resources for production of nanostructures as a substitute for toxic chemicals. This present review includes significant recent improvements concerning the synthesis of agricultural waste biomass-assisted metal oxide nanostructures and their application. The goal is to provide a vision for the use of non-extracted agricultural waste, especially lignocellulosic biomass an inexpensive, green, differentiated resource and policy for the synthesis of valuable nanoporous materials and nanoparticles.

In the present study, Calcium oxide (CaO) obtained from eggshells has been used as a heterogeneous catalyst for biodiesel production from highly viscous non-edible rubber seed oil (RSO). Characterization of synthesized catalyst was done with the help of scanning electron microscope equipped with Energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD) and Fourier transform Infrared spectroscopy (FTIR). Response surface methodology (RSM) with central composite design (CCD) was used to optimize the process parameters and 1 H-NMR (Nuclear Magnetic Resonance) spectroscopy analysis was performed to find the conversion of RSO to biodiesel. A conversion of 99.7% of RSO to biodiesel was obtained at 12:1 methanol to oil molar ratio, 4 (wt%) of catalyst, and 3 hour reaction time with a quadratic regression model of R 2 of value 0.9566 was obtained. The composition of prepared biodiesel is estimated with the help of Gas Chromatogram-Mass Spectroscopy (GC-MS) analysis. Artificial Neural Network (ANN) with Levenberg-Marquardt algorithm was also trained to predict biodiesel conversion and the value of R 2 obtained was 0.9976. It was observed that predicted conversion values from ANN were better when compared to prediction using RSM.

In this prelimnary work, the aim was to fabricate a simple tin (II) sulfide (SnS) quantum dot-sensitized solar cell (QDSSC) from aqueous solution. The SnS QDSSCs were characterized by using current-voltage test (I-V test), scanning electron microscopy (SEM), and ultraviolet-visible (UV-Vis) spectroscopy. SEM results showed the presence of TiO 2 and SnS elements in the sample, confirming the successful synthesis of SnS quantum dots (QDs). The overall efficiency of QDSSCs increased when concentration of the precursor solutions, which were aqueous sodium sulfide and tin (II) sulfate decreased from 0.5 M to 0.05 M. On the other hand, for a fixed precursor concentration, the efficiency of QDSSC reduced once an optimal cycle of of successive ionic layer adsorption and reaction (SILAR) was achieved. The bandgap energies of QDs obtained by extrapolating the Tauc plot were used to predict the QDs size. In general, the QD size was bigger for samples prepared from precursor concentration of 0.5 M, and with higher number of SILAR cycle used. The best performance was obtained from sample prepared from 0.05 M precursor concentration with 4 SILAR cycles.

The aqueous extract of Gypsophila aretioides roots as a “green” or eco-friendly inhibitor of carbonate calcium formation was investigated. The presence of chelating factors such as polyphenol compounds and foaming agents in the plant extract was assessed. Atomic absorption spectroscopy (AAS) demonstrated the ability of G. aretioides extract for dissolution of the carbonate calcium precipitates. Moreover, conductivity measurements revealed that the G. aretioides extract could efficiently retard sedimentation of carbonate calcium from a brine solution of calcium ions exposed to carbonate ions by adding Na 2 CO 3 to the system solution. In addition, chronoamperometry was performed for a period of 3 h by polarizing the steel electrode to -0.9 V (vs. SCE) at 40°C. The presence of G. aretioides extract at a concentration of 10% (w/v) in chronoamperometry prevented the precipitation of CaCO 3 on the steel electrode surface. This was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyses which showed an absence of precipitates and lack of calcium ions on the steel electrode after 3 h chronoamperometry, respectively. However, further studies are required in order to amend the characteristics of G. aretioides extract to render it more applicable as an eco-friendly, cost-effective, anti-scale agent for a wide range of industrial applications.

An efficient and solvent-free acylation of 2-methylnaphthalene (2-MN) is presented using acid chloride as both the acylating agent and solvent in a micro channel reactor. The effect of the catalyst, reactant ratio, mixing temperature, reaction temperature and reaction time on the product yield and selectivity was investigated. At room temperature with a reaction time of only 15 min, the target product, 2-methyl-6-propionylnaphthalene (2,6-MPN), was obtained in 72.3% yield with 73.8% selectivity, and 2-methyl-6-acetylnaphthalene (2,6-MAN) was obtained in 54.1% yield with 55.4% selectivity. The route of synthesis provides a more environmentally friendly and efficient method to prepare 2,6-MPN with no other toxic solvents and efficient mass transfer and heat transfer.

Nature and nanotechnology have not yet achieved a lucid correlation in the field of science but together they have exhibited immense potential towards the advancement and modification in future science and technology. Due to the unique properties of nanomaterials like nanoparticles gained considerable importance. Among all the nanoparticles, zinc oxide (ZnO NPs) are greatly utilized in sensors, catalysis, bioscience, etc. Antimicrobial activity by ZnO NPs had more attention by the implementation of nanotechnology for the preparation of ZnO NPs. At present, antimicrobial activity of ZnO NPs using Aegle marmelos ( A. marmelos ) leaves extract was done. The ZnO NPs subjected to UV-Vis, FT-IR, XRD, SEM and TEM analysis. The presence of phenolic group in extract has the capacity to form ZnO NPs and act as stabilizing agent. Every 5 min interval ZnO NPs was formed which recorded by UV-Vis spectrophotometer. The SEM analysis displayed a fine spherical ZnO NPs and EDAX report showed that the existence of zinc and oxygen in the ratio of 30.51% and 69.49%. The antimicrobial activity of ZnO NPs has high percentage inhibition against A. niger at 1000 ppm. Till now, no research carryout on A. marmelos mediated ZnO NPs and applications towards antimicrobial activity.

A “reactive coupling” process for one-pot transesterification of rapeseed oil into fatty acid methyl esters (FAME) for biodiesel, and in situ acetalisation of the glycerol by-product to solketal was investigated by both an experimental and a kinetic modelling approach. The aim was to develop a process with a more valuable co-products than glycerol, and to minimise glycerol production. The results showed that a one-stage reactive coupling achieved a solketal yield of 39.5 ± 5.1% and FAME yield of 99% after 8 h at 10:7:1 of methanol: acetone: oil molar ratio. However, based on these results and the predictions of the kinetic model developed, a “two-stage” reactive coupling process was investigated, in which some of the acetone was added later in the process. The two-stage process was demonstrated to achieve up to 98 ± 0.5% FAME and 82 ± 4% solketal yields under the same operating conditions.

In this study, enantiomerically pure ( S )-1-phenylethanol was produced via asymmetric bioreduction of acetophenone. Ispir bean (Phaseolus vulgaris ) was used as an alcohol dehydrogenase (ADH) source since whole cells are cheaper than isolated enzymes. Acetone powder methodology was applied for biocatalyst. Glucose was used as a cosubstrate in-order to regenerate cofactor (NADPH). The reactions were carried out in an orbital shaker whose temperature and agitation rate can be controlled. ( S )-1-phenylethanol concentration was analyzed by HPLC using a Chiralcel OB column. Effects of the reaction time, substrate concentration, cosubstrate concentration and biocatalyst concentration on the ( S )-1-phenylethanol production were investigated using Response Surface Methodology (RSM). 36 h bioreduction time, 6 mM acetophenone concentration, 25.15 mM glucose concentration, and 175 mg/mL biocatalyst concentration were determined as optimum values. In these conditions, 2.4 mM ( S )-1-phenylethanol was obtained in phosphate buffer (pH=7.0) at 30°C with >99% enantiomeric excess.

Pyrazolopyridine and pyrazoloquinoline derivatives were obtained by a one-pot, three-component reaction of arylglyoxals, 3-methyl-1-aryl-1 H -pyrazol-5-amines and cyclic 1,3-dicarbonyl compounds in the presence of tetrapropylammonium bromide at 80°C in water through Knoevenagel and Micheal reactions, followed by intramolecular condensation, unexpected dearoylation and oxidation. Mild reaction conditions, high yields, simplicity of work up procedure, starting materials availability and clean product formation are some of the main advantages of this synthetic strategy.

The ability of extraction and preconcentration of small amounts of substances from biological samples is very important in medical toxicology. On the other hand, minimal use of organic solvents is an important issue to prevent environmental damage. In the present study, we developed a new solid phase microextraction fiber using plant extracts as sorbent for extraction and preconcentration of morphine in urine sample. For this purpose, raw carbon nanotubes (CNTs) were functionalized with tobacco extracts. Functionalization was confirmed by Fourier transform infrared (FTIR) and Raman spectroscopy in addition to scanning electron microscope (SEM) images. The functionalized CNTs were coated on polypropylene hollow fiber. The results of HPLC analysis showed that the produced fiber could preconcentrate a very low concentration of morphine (0.25 ng/ml) in small volume of urine samples. Limit of detection (LOD) and limit of quantification (LOQ) for the produced fiber were determined 0.25 ng/ml and 0.825 ng/ml, respectively, and recovery of the fiber was determined 89% at LOQ. The produced fiber provided a recyclable and solvent free method for extraction of a trace amount of morphine, which can be successfully used for up to 30 times with no significant loss in the extraction efficiency.

Two aqueous two-phase systems (ATPS’s) formed by using PEG and sodium citrate/sodium tartrate are applied and compared for extraction of glycyrrhizic acid (GA) from its stock solution. Their binodal curves and tie-lines are studied firstly. Influence of usage amount of the salt and the PEG on the partition coefficient and extraction efficiency is investigated. The highest extraction efficiency and partition coefficient achieved is 73% and 6.5, when the sodium citrate and PEG concentration is 15% and 20% respectively. It is also found that the ATPS based on sodium citrate is better than sodium tartrate for GA extraction. The present study indicates that ATPS formed by biodegradable organic acid salts could be feasible and environment-friendly technique for GA and other bioactive compounds.

Copper oxide nanoparticles (CuO NPs) were green synthesized using walnut leaf extract. Effects of three synthesis parameters namely; amount copper salt (1-4 g), amount of walnut leaf extract (10-40 mL) and furnace temperature (300-500°C), on the particle size as manifested in broad absorption peak (λ max , nm), concentration (absorbance), antioxidant activity and antibacterial activity as minimum inhibitory concentration (MIC) of the fabricated CuO NPs were studied using response surface methodology, based on Box behnken experimental design. The spherical and crystalline monodispersed fabricated CuO NPs with mean particle size of 80 nm, were achieved using optimum synthesis parameters including 1 g copper salt, 14 mL walnut leaf extract and 490°C of furnace temperature. The fabricated CuO NPs at these conditions had maximum antioxidant activity of 83.64% and minimum MIC value of 1.78% w/v against E. coli , with λ max and absorbance values of 226 nm, 4.44% a.u., respectively.

Deep eutectic solvents (DESs) are successfully used as powerful and recyclable catalysts and solvents for the synthesis of 3,4-dihydropyrimidin-2(1 H )-ones/thiones (DHPMs). The acidity of DESs is the main factor that determines catalytic activity. DESs, based on p -toluene sulfonic acid (PTSA) and choline chloride (ChCl), exhibits the highest catalytic activity. ChCl/2PTSA is suitable for a vast variety of aromatic aldehydes with electron-donating and electron-withdrawing groups, different β-diketonates, and urea or thiourea to obtain the corresponding DHPMs. Furthermore, DESs can be recycled easily after synthesis. The reused DESs achieve catalytic efficiency six times without significant changes. This study will provide a new green catalyst and efficient process for the synthesis of DHPMs.

In the current study, silver nanoparticles (AgNPs) were biosynthesised by microwave irradiation using Azadirachta indica. The formation of AgNPs was confirmed by surface plasmon resonance (SPR) band at 408 nm at UV-visible spectroscopy due to reduction of silver metal into (AgNPs) and further confirmed its particles in nano range. Nine different smart-gel hand wash were prepared by dispersing (AgNPs) in the HPMC and/or Pluronic F-127 polymers. The prepared smart gel hand wash was optimized based on pH, viscosity, spreadability, foamability, clarity. The optimized hand wash (NH5) had pH (6.6 ± 0.33), viscosity (66 ± 0.77, cp), spreadability (24.34 g-cm/s), foamability (100 mL). The optimized hand wash (NH5) showed a superior efficacy against pathogenic organisms in comparison to germ protection based marketed hand wash.

In this study, an efficient method for O-methylation of phenolic compound using tetramethylammonium hydroxide (TMAOH) as a new alkylating agent under microwave irradiation was developed. Ethanol was selected as a green reaction media to accomplish this protocol under environmentallybenign conditions. Less than half hour time is needed to obtain good to excellent yields of products at temperature of about 120°C. Using this procedure, phenolic compounds could be converted to the corresponding aryl methyl derivatives quickly. The results indicated that different phenolic compounds bearing both electron-withdrawing and electron-donating groups are O-methylated effectively using TMAOH under microwave irradiation. This novel protocol has many improvements in view point of reaction yields, selectivity and conditions compared to previous studies. Trimethylamine and water were the side products of O-methylation reaction which can be recovered easily from the product mixture. This methodology showed high selectivity for O-methylation and no C-methylated products were observed.

In this report, we present a simple and unexplored procedure for green synthesis of silver nanoparticles featuring exudation of Euphorbia acruensis along with the study of its antibacterial and anticoagulant properties. Analytical techniques like ultraviolet visible spectroscopy (UV-Vis), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) were used to analyse the production, crystallinity and morphology of bio-reduced silver nanoparticles. The antibacterial study was performed by following standard disc diffusion method. Most importantly, the anticoagulant and thrombolytic activities of biogenic silver nanoparticles were evaluated by addition of nanoparticles to human blood samples under practical conditions. These green synthesized silver nanoparticles were found to have potent antibacterial, anticoagulant and thrombolytic properties which make them an attractive choice for future medical applications.

The volcanic ash from the Andes mountain range (Puyehue-Cordon Caulle volcanic complex situated in western South America on the Argentinean-Chilean border) was used as heterogeneous acid catalyst in the suitable synthesis of 3 H -1,5-benzodiazepines. The natural ashes were classified according to their particle size to generate the different catalytic materials. The catalysts were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), vibrational spectroscopies (FT-IR and Raman), and textural properties were determined by N 2 adsorption (S BET ). Potentiometric titration with n-butylamine was used to determine the acidic properties of the catalytic materials. Several 3 H -1,5-benzodiazepines were obtained by reaction of o -phenylenediamine and substituted 1,3-diphenyl-1,3-propanedione in solvent-free conditions, giving good to excellent yields of a variety benzodiazepines. The method was carried out in environmentally friendly conditions and it was operationally simple. The volcanic ash resulted in a safe and recyclable catalyst.

In this work, a chain of reactions has been proposed as a new heterogeneous technique, based on the use of natural treated clays as an environmentally friendly catalysts for the synthesis of poly(1,4-bis(methacryloyl)piperazine). We first synthesized the monomer; 1,4-bis(methacryloyl)piperazine (NBMP) in bulk (without solvent) by the condensation of heterocyclic secondary amines piperazine with methacrylic anhydride catalyzed by maghnite-H + at room temperature during 2 h. After that, we have polymerized anionically the obtained NBMP in an ice bath using anionic catalyst maghnite-Na + at 0°C, the reaction took place in 24 h. The poly(1,4-bis(methacryloyl)piperazine) and NBMP structure was characterized and confirmed by infrared spectroscopy, 1 H and 13 C nuclear magnetic resonance spectroscopies. Thermal properties of the polymer were determined using thermogravimetric analysis. The yield of the reaction was 72% and 59% for the monomer and polymer synthesis respectively. The effect of the weight content of the catalyst on the reaction yield was studied. A polymerization mechanism has been suggested showing the role of maghnite as a catalyst during the reaction courses.

A bench scale submerged fermentation process was used to bioethanol produce using sugar beet molasses and Saccharomyces cerevisiae , as substrate and microbial strain, respectively. Effects of selenium amount on growth of S. cerevisiae and bioethanol production were evaluated. The obtained results indicated that growth of S. cerevisiae (manifested as turbidity intensity) in the samples containing 0, 5, 10, 15, 20 and 25 μg sodium selenite, during aerobic process, was 0.1707, 0.1678, 0.1679, 0.1664, 0.1627 and 0.160% a.u./h (after 14 h incubation), respectively. Statistical analysis based on compression test indicated that there were insignificant (p > 0.05) differences between growth rate of the yeast in the fermented samples containing S. cerevisiae and 5 to 25 μg selenium salt. Response surface methodology was utilized to evaluate effects of two fermentation parameters namely, amount of selenium (5-25 μg) and substrate brix (10-25°Bx) on the concentration (g/L) of produced bioethanol. Obtained results revealed that maximum bioethanol concentration (55 g/L) was achieved using 15 μg selenium and molasses with 25°Bx. Furthermore, results have also indicated that, without using selenium and using molasses with 25°Bx, bioethanol with concentration of 29 g/L was produced.

Silver nanoparticles (Ag NPs) were synthesized using four pathogenic bacterial extracts namely, Bacillus cereus , E. coli , Staphylococcus aureus and Salmonella entericasubsp.enterica . Synthesis process were hydrothermally accelerated using temperature, pressure and heating time of 121°C, 1.5 bar ad 15 min. Physico- chemical characteristics of the fabricated Ag NPs, including, particle size, polydispersity index (PDI), zeta potential, broad emission peak (λ max ) and concentration were evaluated using UV-Vis spectrophotometer and dynamic light scattering (DLS) particle size analyzer. Furthermore, main existed functional groups in the provided bacterial extracts were recognized using Fourier transform infrared spectroscopy. The obtained results revealed that two main peaks were detected around 3453 and 1636.5 cm -1 , for all bacterial extracts, were interrelated to the stretching vibrations of hydroxyl and amide groups which those had key roles in the reduction of ions and stabilizing of the formed Ag NPs. The results also indicated that, Ag NPs with much desirable characteristics, including minimum particle size (25.62 nm) and PDI (0.381), and maximum zeta potential (-29.5 mV) were synthesized using S. e. subsp. enterica extract. λ max , absorbance and concentration values for the fabricated Ag NPs with this bacterial extract were 400 nm, 0.202% a.u. and 5.87 ppm.

Monoaldehydes and dialdehydes are parts of millions of compounds and are extremely versatile intermediates. For the synthesis of monoaldehydes, one impressive approach to date, because of its excellent selectivity, high yield and stability towards over-oxidation and over-reduction, is the oxidation of organic monohalides. Numerous monohalides oxidation based methodologies to afford monoaldehydes are disclosed in literature. In this research work, twelve well-known approaches (well-documented for synthesis of monoaldehydes from monohalides) are investigated for their effectiveness towards synthesis of organic dialdehydes from organic dihalides. The classical approaches under investigation include modified Sommelet oxidation, Kröhnke oxidation, sodium periodate-mediated oxidative protocol, manganese dioxide-based oxidative approach, Kornblum oxidation and Hass-Bender oxidation. The eco-friendly approaches under observation include periodic acid-based IL protocol, periodic acid in vanadium pentoxide-mediated IL method, hydrogen peroxide in vanadium pentoxide-based approach, hydrogen peroxide-mediated IL methodology, IBX-assisted IL protocol and bismuth nitrate-promoted IL technique. In this investigation yield, overoxidation, eco-friendliness, cost-effectiveness and recyclability are the main parameters which are under examination. Hopefully, this research will help chemists in carrying out routine operations in organic synthesis and will also be fruitful to select finest synthetic approach, develop further new transformational methodologies and improve current transformational approaches for the synthesis of dialdehydes.

Pyrolysis of palm oil is one of the most potential methods to obtain bio-oil. In this study, pyrolysis of palm oil was carried out by using zeolites as a catalyst. The use of HCl and NaOH as activating agents of the zeolites prior to its use in the pyrolysis process was investigated. The result showed that a 1 M concentration of either HCl or NaOH gave an optimum result when the zeolites were used to absorb methylene blue. When 1 M of HCl was used as the activating agent, a more uniform pore size of the zeolites was obtained, along with a more opened pore structure. A GC-MS analysis showed that by using zeolites which was activated using HCl or NaOH, the pyrolysis of palm oil yielded bio-oil with a high content of organic compounds.

Aqueous pollution due to textile industry is an important issue. Photocatalysis is one of the methods used for eradication of dyes from textile industrial effluents. In this study, the synthesis, characterization and evaluation of photo catalytic activity of Ag-TiO 2 is reported. TiO 2 catalysts with 2, 4, 6 and 8% loading of Ag were prepared by green methods using Azadirachta indica leaves extract as reducing agent with titanium dioxide and silver nitrate as precursor materials. Prepared catalyst was characterized by advanced techniques and was used as catalyst for degradation of Methylene blue and Rhodamine B dyes. Deposition of Ag greatly enhanced the catalytic efficiency of TiO 2 towards degradation of dyes. Irradiation of catalyst excites electrons from conduction band of catalyst to valence band yielding an electron-hole pair. This electron-hole pair undergoes secondary reactions and produce OH ∙ radicals. These active radicals take part in degradation of dyes. More than 90% dyes were degraded in 120 min. Photo catalytic degradation of Methylene blue and Rhodamine B followed Eley-Rideal mechanism which states that dye react in fluid phase with adsorbed oxygen.

Catalytic efficiency in synthesis of vitamin E succinate was dramatically increased via the preparation of robust catalyst and the improvement of reaction system. 4-dimethylaminopyridine (DMAP) was covalently immobilized on nano-SiO 2 to avoid the catalyst contamination of the product and permit the easy recycling of DMAP. Then, a hexane-acetone mixed solvent system was firstly introduced to replace the traditional single-solvent system, which was employed to improve the activity of immobilized DMAP derivative and the substrate solubility of the reaction system. The highest vitamin E succinate yield of 94% was achieved. In addition, the recyclability and stability of the immobilized DMAP derivative was excellent, the yield of vitamin E succinate had no obvious loss and remained 90% after recycling 20 times. The excellent results make this technology be a promising candidate for the industrial production of vitamin E succinate.

Extraction with supercritical carbon dioxide (SC-CO 2 ) which is known as a clean technology was carried out to extract oil from melon ( Cucumis melo ) seeds. SC-CO 2 extraction technique does not contaminate extracts. SC-CO 2 is not a toxic and a flammable solvent. Phytosterols, natural and bioactive compounds, which is known to provide protection against various chronic diseases were examined in the seed oil by using gas chromatography – mass spectrometry (GC-MS). Stigmasterol and β-sitosterol were detected in the melon seed oil. SC-CO 2 extractions were performed in a range of 30-55°C, 150-240 bar, 7-15 g CO 2 /min, 0.4-1.7 mm (mean particle size of the seeds) and 1-4 h. The optimal quantities of extracted oil, β-sitosterol and stigmasterol were 36.8 g/100 g seed, 304 mg/ kg seed and 121 mg/ kg seed, respectively, at 33°C, 200 bar, 11 g CO 2 /min, 0.4 mm and 3 h.

The hydrolysis of high methyl ester citrus-apple pectin as a model substance for plant biomass waste rich in pectin fraction resulting in an uronic acids was performed in a batch reactor using subcritical water. The effects of the reaction temperature and time on the composition of the products contained in the separated liquid fractions were studied. The optimal experimental design methodology was used for modelling and optimizing the yield of uronic acids. In good agreement with experimental results (R2 = 0.986), the model predicts an optimal yield of uronic acids (approx. 77.3 g kg -1 ± 0.7 g kg -1 ) at a temperature and a time of about 155°C and 36 min. Uronic acids were isolated from reaction mixture using the ion exchange method. Higher temperature and longer holding time resulted in a greater degree of thermal degradation of uronic acids and simultaneously higher yield of losses and gas fractions

A facile novel green methodology is presented for the synthesis of highly stable and well-dispersed copper oxide nanoparticles using aqueous wheat seed extract. Under optimal reaction conditions, the wheat seed extract-derived electron-rich biomolecules were functioned as a reducing and capping/ stabilizing agent. The ultraviolet-visible absorption peak at 300 nm was confirmed the formation of copper oxide nanoparticles. Fourier-transform infrared spectroscopy analysis determined Cu–O bonds in nanosample, indicating the active role of functional groups in the wheat seed extract in bio-reduction of Cu cations. X-ray diffraction pattern results demonstrated the monoclinic structure of highly pure biosynthesized copper oxide nanoparticles with a crystallite size of 20.76 nm. The stability of copper oxide nanoparticles was confirmed after 3 months’ storage of product with no sedimentation or suspension. Transmission electron microscopy results showed the spherical shape of nano-particle with an average size of 22 ± 1.5 nm. X-ray photo-electron spectroscopy analyses revealed only copper and oxygen elements in the sample, confirming the purity of copper oxide nanoparticles. Bio-assisted copper oxide nanoparticles demonstrated significant catalytic efficiency and reusability toward 4-nitrophenol removal by an average of 97.6% from aqueous solutions after successive 5 days’ exposure to UV irradiation.

In this study, Artificial intelligence method was used as a new approach in modelling and optimization of printing toners with appropriate requirements. Toner fine powder is made up of resin, colorant and additives. This composite has been utilized in electrophotographic digital printing. The optimization approach has been considered for optimizing of toner production process and to produce printing toners with an appropriate physical and color properties (particle size (PS), particle size distribution (PSD), L*, a*, b*) by an environmental friendly method which is emulsion aggregation (EA). The EA is a green technology that provides many advantages for toner production pathway and lead to high quality product and printing. The effect of heating rate (R), time of mixing (T), and mixing rate (S) on PS, PSD, and L*, a*, b* has been studied. An in-home code was established to optimize the architecture of artificial neural network (ANN) with two hidden layers, by which an accurate model was developed for the prediction of toner properties. The best process conditions with acceptable characteristics of manufacturing toners was obtained by multi-objective optimization in specified amounts of heating rate, mixing time, and mixing rate

In this study removal of methylene blue (MB) from an aqueous solution by zeolite (NaY) and related modified hierarchical zeolite (MY) has been investigated. The NaY zeolite with a low ratio of Si/Al was synthesized from silica extracted rice husk ash. It was transformed to hierarchical zeolite (MY) by a “destructive-constructive” modification method using tetramethyl ammonium hydroxide (TMAOH) and a cationic surfactant (Cetyltrime-thylammonium bromide, CTAB) as a templating agent. Various characterization method like FT-IR, XRF, XRD, BET, TGA, SEM and BJH confirmed the construction of parent zeolite and also successfulness of the modification process. EDX showed a negligible change of Si/Al ratio during modification which is favorite in adsorption of cationic MB dye. In order to study the interaction between the surface of adsorbent and adsorbate, six common isotherms were used. By Langmuir isotherm, it is clarified that, the maximum adsorption capacity (q m ) had improvement from 15.2 mg g -1 to 133.1 mg g -1 for NaY and MY, respectively. The kinetic studies showed that the adsorption obeys the Pseudo-second order model for both NaY and MY zeolites. Also, the usage frequency of the MY was investigated. Results showed that there was not any noticeable change in performance of adsorption after four circles.

Two simple, efficient, and environmentally benign protocols for the synthesis of various N -arylacetamides via N -acetylation of arylamines and straightforward one-pot reductive acetylation of aromatic nitro compounds promoted by CuFe 2 O 4 nanoparticles in water at reflux have been developed. The prepared CuFe 2 O 4 MNPs are well known and fully characterized by various techniques. Furthermore, the CuFe 2 O 4 NPs easily separated from the reaction environment using an external magnetic field and can be reused for several times without significant loss of its activity for both mentioned reactions.

Moringa oleifera oil (MOO), a second-generation lipid feedstock that has been reckoned as a promising feedstock for biodiesel production in recent years. In the current study, crude MOO possessing high acid value (80.5 mg of KOH/g) was subjected to two step esterification and transesterification process for biodiesel production and the process was applied with central composite design (CCD) based response surface methodology (RSM). The results showed that H 2 SO 4 concentration of 0.85 vol%, reaction time of 70.20 min, and methanol to oil ratio of 1:1 (vol/vol) significantly decreased the acid value to 3.10 mg of KOH/g of oil. Moreover, copper oxide-calcium oxide (CuO-CaO) nanoparticles were developed and evaluated as a novel heterogeneous base catalyst for synthesizing Moringa oleifera methyl esters (MOME). The synthesized catalyst was scrutinized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDAX) analysis. Copper oxide (CuO) was perceived to be the dominant phase in the synthesized catalyst. Highest MOME conversion of 95.24% was achieved using 4 wt% CuO-CaO loading, 0.3:1 (vol/vol) methanol to oil ratio and 150 min reaction time as the optimal process conditions.

In this work, stearic acid esters were prepared using [HPY][HSO 4 ] ionic liquids as catalysts and different kinds of alcohols and stearic acid as reactants in a self-designed reactor. Catalytic esterification, kinetics analysis and low temperature fluidity of the esters were studied. Through single-factor experiment, the optimal reaction conditions were determined for methyl stearate, ethyl ester, propyl ester, butyl ester, and amyl ester. The conversion rates under the optimized conditions were all above 97%. The kinetics of the reaction process of all five esters was analyzed by the integral method, and the activation energy, pre-exponential factor and kinetic model were obtained for the five esters. Finally, the low temperature fluidity of all esters was tested and the best value was observed for amyl alcohol. Therefore, these esters would be useful additives for reducing the condensation and cold filter plugging points of biodiesel, thus improving the cold flow properties of biodiesel.

This paper proposes a standardized format for the preparation of process green synthesis reports that can be applied to chemical syntheses of active pharmaceutical ingredients (APIs) of importance to the pharmaceutical industry. Such a report is comprised of the following eight sections: a synthesis scheme, a synthesis tree, radial pentagons and step E-factor breakdowns for each reaction step, a tabular summary of key material efficiency step and overall metrics for a synthesis plan, a mass process block diagram, an energy consumption audit based on heating and cooling reaction and auxiliary solvents, a summary of environmental and safety-hazard impacts based on organic solvent consumption using the Rowan solvent greenness index, and a cycle time process schedule. Illustrative examples of process green synthesis reports are given for the following pharmaceuticals: 5-HT2B and 5-HT7 receptors antagonist (Astellas Pharma), brivanib (Bristol-Myers Squibb), and orexin receptor agonist (Merck). Methods of ranking synthesis plans to a common target product are also discussed using 6 industrial synthesis plans of apixaban (Bristol-Myers Squibb) as a working example. The Borda count method is suggested as a facile and reliable computational method for ranking multiple synthesis plans to a common target product using the following 4 attributes obtained from a process green synthesis report: process mass intensity, mass of sacrificial reagents used per kg of product, input enthalpic energy for solvents, and Rowan solvent greenness index for organic solvents.

This paper reports the way for the synthesis of nanoplate VO 2 (B) particles with controlled morphology. Nanoplate VO 2 (B) particle was synthesized by hydrothermal method. Microstructure of VO 2 (B) particles were controlled by hydrothermal temperatures and use of Zn doping into VO 2 (B) matrix. The microstructure of the particles was shifted from nanowires to nanoplate morphology by changing of hydrothermal temperatures. The doping of Zn into VO 2 nanoparticles resulted in an effective achievement of VO 2 (B) phase. In addition, luminescence of VO 2 (B) nanoparticle was also controlled by the use Zn doping. These results suggest that the potential application of Zn doped VO 2 (B) particles for potential application in optical and energy techniques.

Uranium plant wastewater was treated in laboratory scale experiments by employing zero valent iron powder. Batch experiments conducted by the response surface methodology (RSM) proved significant decrease in concentrations of uranium due to a decrease in an oxidation-reduction potential and an increase in pH relative to an application of zero valent iron powder. Results indicated that it is effective on the removal of uranium from uranium plant wastewater with the uranium concentration of 2772.23 μg/L due to the adding of zero valent iron powder. it was found that the scope of pH is widely from 3 to 5 from the experimental data obtained in this study. The predicted model obtained from response surface methodology is in accordance with experimental results.

Nickel-containing residue (NCR) is a hazardous solid waste from battery production lines. Recently, the interest in recovering valuable metals from NCR has increased because sustainable utilization of resources is more and more valued. Drying is a key part of the recovery process. In this study, we measured the dielectric properties of the NCR for different moisture contents and temperatures using the cavity perturbation method at 2.45 GHz. The microwave absorption characteristics of NCR had a positive correlation with the moisture content, while it was less efficient in the 20-180°C temperature range. Then found that the microwave drying data at different microwave powers (400-700 W) and for different sample weights (60-120 g) have a better fit with the Midilli-Kucuk model. The activation energy (Ea) was received as 9.76 W/g using an exponential expression based on the Arrhenius equation. Finally, the energy consumption reduce 110 W·h/kg than that of drying with a single microwave power by optimizing the microwave drying process.

5-bromo-2,3-dimethoxy-6-methyl-1,4-benzoquinone 3 , a key intermediate for preparing coenzyme Q compounds, was readily synthesized in two steps by a reaction sequence starting from the commercially available 3,4,5-trimethoxytoluene 1 via bromination and oxidation reactions. Persulfate salts were first employed as oxidants to synthesize 1,4-benzoquinone, the overall yield of title compound 3 was 65%.

Biodiesel production from waste cooking oil was obtained using Thermomyces lanuginosus (TL) lipase (E.C.3.1.1.3) anchored on Fe 3 O 4 /Au nanoparticles through physical interactions. A remarkable biodiesel yield of ∼90% was obtained without any pre-treatment and at a lipase concentration of 20%, 45°C reaction temperature, 1:6 oil/methanol molar ratio, after 24 h. The immobilized enzyme showed fast kinetic (the biodiesel yield was already of 34.6% after only 3 h) and activity slightly dependent on the length of the acid chains. The effect of the Au NPs sizes was monitored, to study the role of Au conduction centres in facilitating enzymes favourable orientation. The immobilized lipase activity stays above 74% after the first 3 cycles of use. In particular, the produced biodiesel presents an ester content of 97.8% ± 0.21 and a linolenic methyl ester content of 0.53% ± 0.03, in agreement with EN14214 requirements.

Blue coke-based activated carbon (BAC) was prepared via CO 2 activation with disused blue coke powder as raw materials at high temperature. The factor of activation temperature was intensively studied. The properties of sample were characterized by N 2 adsorption-desorption techniques, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), and the activation mechanism was also proposed. The results showed that, with the increase of temperature, the yield of BAC decreased, while the iodine adsorption increased first and then decreased. The N 2 adsorption-desorption isotherms revealed that the BAC had both micropores and mesopores, and the optimal temperature of porosity development was at 900-1000°C. When the activation temperature reached 1000°C, the maximum Brunauer-Emmett-Teller (BET) specific surface area and pore volume of BAC were 636.91 m 2 ·g -1 and 0.3627 cm 3 ·g -1 , respectively. The FTIR results indicated that BAC surface contained large amounts of surface functional groups such as hydroxyl, ester, carboxyl, and so on. The content of them decreased with the increase of temperature. Mechanism analysis shows that radial hole-making function happen first then transverd hole-enlarging function as the temperature increases, for the formation of large amount of microporous, the radial activation was the main controlling process.

In the current study, the optimal reaction condition for fabrication of INPs by using pine tree ( Pinus eldarica ) leaf extract was developed. A fractional factorial design was utilized to screen the effective parameters in the green synthesis reaction, and central composite face design was employed to achieve the optimal reaction condition. Leaf extract and iron precursor concentrations were found to be the most effective parameters for the fabrication of INPs. Physicochemical characteristics of the obtained nanoparticles were evaluated by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), and derivative thermo gravimetric (DTG). The prepared particles were found to be zero-valent iron nanoparticles without any iron oxide impurities. Nanoparticles were spherical in shape with diameters ranging from 8 nm to 34 nm with a mean particle size of 18 nm. The fabricated particles were amorphous with a low magnetization value of 33 memu/g.

Aiming to design a green and efficient protocol for squalane production from low-cost biomasses, a practical and scalable procedure for squalene extraction and hydrogenation to squalane is presented herein. The oil-deodoriser distillates that are produced by the vegetal-oil production chain are a renewable and cheap source of squalene. We were able to isolate an enriched fraction containing 89.0% of pure squalene (yield 55.4%) from a matrix containing about 2% squalene. Efficient microwave- assisted esterification under heterogeneous catalysis enabled the separation of fatty-acid methyl esters (FAME) via vacuum distillation. The residue was purified by flash-chromatography on a C-18 silica column using MeOH/H 2 O/2-propanol as the mobile phase. Finally, squalene was hydrogenated to the more stable squalane in a pressure-resistant microwave reactor. The reaction was performed over a Pd/C catalyst in EtOH, and even in solvent-free conditions, and was optimised using commercial squalene (5 bar of H 2 at 100°C for 1 h).

Rare earth tailings from the Bayan Obo mine are rich in rare earth, iron, and other catalytically active substances. In this study, Na 2 CO 3 and Ca(OH) 2 were mixed with rare earth tailings, roasted, and the tailings modified by HCl-citric acid leaching and pickling to prepare high-performance rare earth tailings-based denitrification catalysts. Denitrification performance tests show that, in the temperature range 700°C~900°C, the alkali and acid co-processed modified tailings sample gave the best catalytic denitrification performance. XRD, SEM, and H 2 -TPR analyses show that, compared with raw ore samples, Fe activity sites increased after alkali and acid co-treatment. Cracks and holes appeared on the surface of the sample, and the reduction temperature range was broadened. XPS analysis showed that Fe coexisted in the forms Fe 2+ and Fe 3+ , and Ce in the forms Ce 3+ and Ce 4+ . At a rare earth tailings microwave roasting temperature of 500°C, NO concentration of 500 ppm, CO/NO ratio 4:1, and reaction temperature of 900°C, the denitrification efficiency of the catalyst was optimal, at up to 96.2%. In this study, a relatively green and pollution-free method was used to prepare catalysts, which can provide reference for solving the problem of rare earth tailings accumulation.

The bacterial communities (Gram-negative and Gram-positive) form the biofilms which oppose the mode of action of antibiotics and affecting the immune system of the human. These chronic infections related to biofilm are always hard to be cured because of their inherent resistance to both antimicrobial agents and host defense. The present study is devoted to the synthesis of silver nanoparticles (AgNPs) using aqueous extracts of Averrhoa bilimbi leaf and Plum fruit ( Prunus bokharensis ) and its inhibitory effect on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa , and Salmonella typhi . Here, AgNPs) were successfully prepared by green synthesis method obtained by the reduction of silver nitrate into silver ions. The synthesized AgNPs were characterized by UV-Vis Spectroscopy, XRD, FTIR, FESEM-EDAX and DLS analysis. The antimicrobial effects of the two extract were evaluated by the disk diffusion method. The green synthesized AgNPs exhibited good antibacterial activity against both Gram-negative and Gram-positive. They were also analyzed for their significant antibacterial activities against all the test cultures exposed whereas Escherichia coli and Salmonella typhi topped among other test cultures. The anti-proliferative activity of phytochemical mediated synthesis of Ag NPs was investigated for their cytotoxicity in Vero and Human epidermoid larynx carcinoma cell lines (HEp-2) based on their viability using MTT assay. The present study also represents the synergistic bioactivity of silver nanoparticles using in vitro models.

Nanoparticles are smaller than nuclei having large surface area and more reactivity. Green production of metals and metal oxide nanoparticles is a benign and sustainable approach. Present work deals with the green production and optimization of nanoparticles by using indigenous plant growth promoting bacteria. Four different methods were used for silver nanoparticles (AgNPs) synthesis, i.e. extracellular, intracellular, oven assisted and extended incubation period. With extended incubation period AgNPs production improved. The nanoparticles synthesized were then applied to Triticum aestivum L. and their phytostimulatory impact was evaluated. The results revealed the growth promotional ability of nanoparticles. It is concluded that nanoparticles stimulate growth of Triticum aestivum L. with significant improvement in shoot length, root length, number of leaves and fresh weight. Thus in the present work we report environmentally benign nanoparticles exhibiting phytostimulatory potential. Biosynthesis of AgNPs by bacteria is a safe easy, less time consuming and economical approach which can be utilized as an alternative method to conventional chemical and physical approaches. Biosynthesized AgNPs can be effectively utilized as environment friendly nanofertilizers for plant growth promotion.

The photocatalysis of Ag/Ni bi-metallic nano-particles on safranin O dye degradation was evaluated by UV light irradiations. Ag/Ni bi-metallic nanoparticles were synthesized by the green approach using Zingiber officinale root (Zinger) extract. The average particles size of Ag/Ni bi-metallic nanoparticles was found to be 70-88 nm from SEM image and from XRD patterns it was confirmed that the existence of Ag/Ni bi-metallic nano-particles. 8 mg of Ag/Ni bi-metallic nanoparticles present in 40 mL of 10 ppm dye, degraded completely in presence of UV light irradiations within 30 min time durations. The effect of dye degradation within a short period of time (30 min) was due to wide band gap energy and photochemical redox reactions.

The aim of this study was to apply the central composite design technique to study the interaction of the amount of formic acid (6-12 mL), amount of hydrogen peroxide (6-10 mL), temperature (54-58°C) and reaction time (40-60 min) during the oxidative desulphurisation (ODS) of tyre-derived oil (TDO). The TDO was oxidised at various parametric interactions before being subjected to solvent extraction using acetonitrile. The acetonitrile to oil ratios used during the extraction were 1:1 and 1:2. The content of sulphur before and after desulphurisation was analysed using ICP-AES. The maximum sulphur removal achieved using a 1:1 acetonitrile to oxidised oil ratio was 86.05%, and this was achieved at formic acid amount, hydrogen peroxide amount, temperature and a reaction time of 9 mL, 8 mL, 54°C and 50 min respectively. Analysis of variance (ANOVA) indicated that the reduced cubic model could best predict the sulphur removal for the ODS process. Coefficient of determination (R 2 = 0.9776), adjusted R 2 = 0.9254, predicted R 2 = 0.8356 all indicated that the model was significant. In addition, the p-value of lack of fit (LOF) was 0.8926, an indication of its insignificance relative to pure error.

CO 2 sequestration by reaction with abundant, reactive minerals such as olivine has often been considered. The most straightforward, direct process consists in performing the reaction at high temperature and CO 2 pressure, in view to producing silica, magnesium and iron carbonates and recovering the traces of nickel and chromite contained in the feedstock mineral. Most of direct processes were found to have an overall cost far larger than the CO 2 removal tax, because of incomplete carbonation and insufficient properties of the reaction products. Similar conclusions could be drawn in a previous investigation with a tubular autoclave. An indirect process has been designed for high conversion of olivine and the production of separate, profitable products e.g. silica, carbonates, nickel salts, so that the overall process could be economically viable: the various steps of the process are described in the paper. Olivine particles (120 μm) can be converted at 81% with a low excess of acid within 3 h at 95°C. The silica quantitatively recovered exhibits a BET area over 400 m 2 g -1 , allowing valuable applications to be considered. Besides, the low contents of nickel cations could be separated from the magnesium-rich solution by ion exchange with a very high selectivity.

This work is focused on the synthesis of organic carbonates from CO 2 and ethanol. A parametric study of the synthesis of diethyl carbonate from ethanol is performed in a 100 mL batch reactor. The influence of pressure and temperature is studied and we prove that the presence of water strongly decreases the yield in diethyl carbonate as an equilibrium is quickly reached. One method to improve this yield is to remove water from the reaction mixture to shift the equilibrium toward the formation of carbonates. The chemical methods give good results but separation and regeneration associated steps are prohibitive. For these reasons, a physical technique like pervaporation is chosen to remove water. The study of a pervaporation cell with membrane PERVAP 4100 gives good results for the dehydration of ethanol alone even at low concentrations of water from 0.33 %wt to 0.15 %wt. Twelve experiments on the dehydration of a mixture of ethanol, diethyl carbonate and water are performed. The calculated separation factors show a very good selectivity for water. That means that even in the presence of diethyl carbonate, the membrane has still a selective water permeability.

The spinning disc reactor (SDR) uses surface rotation to produce thin film flow with improved mixing and reduced residence times in chemical processing applications. Solvent-antisolvent precipitation is one such process that can benefit from these properties. This study investigates the film hydrodynamics and precipitation of starch nanoparticles by contacting starch dissolved in sodium hydroxide with ethanol as the antisolvent. One objective of this study is to understand how interactions of the disc surface topography (grooved and smooth) with other parameters such as liquid flowrate, antisolvent to solvent flow ratio and disc speed impact the mixing and precipitation processes. Results indicate that an increase in flow rate and rotational speed leads to smaller nano-particles and narrower size distributions, which is attributed to increased shear and instabilities within the liquid film. It was also observed that an increased antisolvent to solvent ratio caused a reduction in particle size, as increased antisolvent generated higher supersaturation. Results showed that although particle size was not significantly influenced by the disc texture, the size distribution was narrower and higher yields were obtained with the grooved disc surface. The grooved disc therefore offers the opportunity for higher throughput in the solvent-antisolvent precipitation of starch particles with better product quality.

Synthesis of styrene carbonate (SC) via the fixation of CO 2 with styrene oxide (SO) has been investigated using a combination of zinc bromide (ZnBr 2 ) and tetrabutylammonium halides (TBAX) as acid-base binary homogeneous catalysts. The combination of ZnBr 2 and TBAB had a synergistic effect, which led to about 6-fold enhancement in the rate of SC formation as compared to using TBAB alone as a catalyst. Propylene carbonate (PC) was chosen as a green solvent for a comprehensive study of reaction kinetics. The reaction followed a first-order kinetics with respect to SO, CO 2 , and TBAB, whereas a fractional order was observed for the ZnBr 2 when used in combination with the TBAB. Arrhenius and Eyring’s expressions were applied to determine the kinetic and thermodynamic activation parameters, where activation energy (E a ) of 23.3 kJ mol −1 was obtained for the SC formation over the temperature range of 90-120°C. The thermodynamic analysis showed that positive values for enthalpy (ΔH ‡ = 18.53 kJ mol −1 ), Gibbs free energy (ΔG ‡ = 79.74 kJ mol −1 ), whereas a negative entropy (ΔS ‡ = –162.88 J mol −1 K −1 ) was obtained. These thermodynamic parameters suggest that endergonic and kinetically controlled reactions were involved in the formation of SC from SO and CO 2 .