Presence Of Potassium Hydroxide Research Articles

8(S)-[(1R,2S,5R)-2-Isopropyl-5-methylcyclohexyloxy]-3,4-dihydro-2H-[1,4]dithiepino[2,3-c]furan-6(8H)-one

The interaction of propane-1,3-dithiol with the chiral bis-thioether, which combines two 2(5H)-furanone moieties, bridged through their carbon atoms C(4) by the propane-1,3-dithiol fragment, in DMF in the presence of potassium hydroxide or cesium carbonate resulted in the formation of an optically active fused bicyclic sulfur heterocycle, possessing 1,4-dithiepine and unsaturated γ-lactone moieties. The studied reaction follows an unexpected pathway in a basic medium with the thiolate–thiolate exchange. The structure of the novel heterocycle of the 1,4-dithiepinofuranone series is characterized by single-crystal X-ray diffraction.

Rebiopolyols – New components for the synthesis of polyurethane biofoams in line with the circular economy concept

The primary goal of the research presented here was to evaluate the possibility of chemolysis of polyurethane biofoams synthesized from vegetable oil-based biopolyols with different chemical structures. As a reference material, a foam synthesized in 100 % from a petrochemical polyol was used. Chemolysis of polyurethane foams was conducted by using diethylene glycol as a solvent with a 1.5:1 wt ratio of biopolyurethane scraps to glycol. The reaction was carried out at 180 °C for 100 min in the presence of potassium hydroxide as a catalyst. The results of the chemolysis of different polyurethane foams were evaluated in terms of the hydroxyl number, amine value, viscosity, molecular weight and FTIR analysis of the new rebiopolyols. It can be concluded that the chemical structures of different biopolyols (obtained through the method of transesterification of vegetable oils with two different reagents and a two-step method of epoxidation and oxirane rings opening) that are used to make biopolyurethane foams have an impact on the course of the chemolysis process and the properties of resultant rebiopolyols.In order to verify the application possibilities of the new components obtained in accordance with the idea of circular economy, extreme conditions were applied in the form of complete replacement of the polyol in the reference foam with the rebiopolyols. It was found that replacing the petrochemical polyol with the repolyol results in partial cell opening, and replacing this component with the rebiopolyols results in open-cell foams. Only the rebiopolyol derived from the biofoam with the biopolyol obtained by transesterification of oil with triethanolamine was not suitable for use in a polyurethane system because its reactivity was too high. In conclusion, there is no need to use catalysts to obtain new biofoams from rebiopolyols given the catalytic nature of the new biocomponents.

Naphthyl cyanoketene N,S-acetals in glycoside synthesis: a new preparative route to a new class of N-naphthylcyanoacrylamide thioglycosides and their conversions to naphthyl–pyrazole hybrids

The novel N-naphthylcyanoacrylamide thioglycosides 4 were readily prepared by the reaction of N-napthylcyanoacetamide 1 with aryl isothiocyanates in the presence of potassium hydroxide, followed by coupling of the produced salts 2 with 2,3,4,6-tetra-O-acetyl-α-d-gluco- and galacto-pyranosyl bromides 3. The N-naphthyl acrylamide thioglycoside 12 was prepared by the reaction of N-napthylcyanoacetamide 1 with glucose isothiocyante 10 in the presence of potassium hydroxide, followed by alkylation of the produced salt 11 with methyl iodide. The reaction of thioglycoside compounds 4 with hydrazines afforded the corresponding naphthyl-pyrazole hybrids.

Synthesis of substituted cyclohexenones by reaction of chalcones with acetoacetic acid amides

New 4-aryl-2-oxo-6-phenyl-3-cyclohexene-1-carboxamides were obtained by the reaction of N -substituted acetoacetic acid amides with benzalacetophenone and 4-methoxybenzalacetophenone in alcohol in the presence of potassium hydroxide. Structure of the prepared compounds was proved using IR, 1H and 13C NMR spectroscopy, mass spectrometry and X-rays analysis data.

Carbon-supported Ternary Nanocatalyst Palladium-Vanadium-Cobalt for Hydrodechlorination of 2,4-Dichlorophenol

M ultimetallic nanocatalysts have remarkably revealed activities in various catalytic applications. Herein, the ternary nanocatalysts based on palladium-vanadium-cobalt were successfully synthesized through the reduction of their salts with the combination of sodium borohydride and ethylene glycol as reducing agents, including impregnating of activated carbon (AC) substrate with colloid solution of metallic nanoparticles (PdVCo/C). The immobile of trimetallic PdVCo on AC was evidenced by XRD, EDX analysis, transmission electron microscopy (TEM) and specific surface area (BET). Therein, TEM imaging showed that the PdVCo particles size is about 7 nm. The trimetallic nanocatalysts were evaluated in the hydrodechlorination of dichlorinated substrates which was defined by GC (FID detector). The obtained result was that the conversion of 2,4-dichlorophenol was over 91% in the case of PdVCo nano-catalyst in the presence of potassium hydroxide and the high catalytic stability was observed.

Efficient Mineralization of Fluoroelastomers Using Superheated Water in the Presence of Potassium Hydroxide.

The mineralization of fluoroelastomers (FKMs) in superheated water in the presence of potassium hydroxide (KOH) was investigated with the aim of developing a methodology for recycling the fluorine element. Two FKMs-an "uncrosslinked FKM", representing a poly(vinylidene fluoride-co-hexafluoropropylene) (poly(VDF-co-HFP)) copolymer with a VDF/HFP molar ratio of 78/22 and a "crosslinked FKM" consisting of this copolymer (cured by peroxide) and carbon black-were treated. The fluorine content of these FKMs was efficiently transformed into F- ions in the reaction solution using low KOH concentrations (0.10-0.50 M) at 200-250 °C. When the uncrosslinked or crosslinked FKMs reacted with aqueous KOH (0.20 M) at a rather low temperature (200 °C) for 18 h, the fluorine content of these FKMs was completely mineralized (both F- yields were 100%). Although the crosslinked FKM contained carbon black, the fluorine mineralization of the FKM was not inhibited. The addition of Ca(OH)2 to the reaction solutions after the superheated water treatment at 250 °C for 6 h with aqueous KOH (0.50 M) led to the production of pure CaF2, identified using X-ray spectroscopy, with 100% and 93% yields for the uncrosslinked and crosslinked FKMs, respectively.

ENGINE PERFORMANCE TEST EVALUATION OF BIODIESEL BLENDS FROM CASTOR SEED OIL AT VARYING MIXTURE RATIOS AND ENGINE SPEED

The growing global demand for energy with expected fossil fuel shortages stresses the search for alternative energy sources. Moreover, the high fossil energy consumption with its adverse impact on environment and climate changes calls for cleaner fuels. One of the most alternative fuel sources is the extraction of biofuels from Castor oil by acid-based catalysed trans- esterification process. In this study, experimental analysis was carried out to produce biodiesel from castor oil using trans- esterification process. The trans- esterification process occurs between castor oil and methanol in the presence of potassium hydroxide (KOH) as a catalyst. The biodiesel fuel produced was varied at different mixture ratios with diesel. The high viscosity and acid value of the castor oil was further reduced by two-three stage trans-esterification process to within the American Society for Testing and Materials (ASTM) D6751 – 0.2 limits for biodiesel. The biodiesel was tested in a single cylinder diesel engine and results of gas emission, load analysis, fuel consumption rate and engine efficiency were all obtained which are close to those of diesel fuel thus confirming that it can be used as alternative fuel for diesel engines. The Brake thermal efficiency was 96% at B-20 biodiesel blend which is close to the conventional diesel engine efficiency of 95.5%.

Nanoarchitectonics and Molecular Docking of 4-(Dimethylamino)Pyridin-1-Ium 2-3 Methyl-4-Oxo-Pyri-Do[1,2-a]Pyrimidine-3-Carboxylate

A retro-Claisen reaction of 1-(4-oxo-4H-pyrido [1,2-a]pyrimidin-3-yl)butane-1,3-dione, 3, in the presence of potassium hydroxide and 4-dimethylamino-pyridine has been carried out, leading to 4-(dimethylamino)pyridin-1-ium 2-methyl-4-oxo-pyrido [1,2-a]pyrimidine-3-carboxylate 5. A plausible mechanism explaining the formation of the title compound has been proposed. A single-crystal X-ray diffraction analysis confirms the crystal structure of the isolated organic salt (5). In the crystal, the title compound adopts a layered structure where there are stacks of cations and anions formed by slipped π-stacking interactions. These stacks are linked by regions consisting of water molecules that are hydrogen-bonded together. DFT and Hirshfeld surface analysis supported the experimental results of the molecular geometry and the intercontacts between different units in the crystal. The druglikeness, ADMET properties, and predicted targets were investigated, and the observed results suggest that 5 may act as a carbonic anhydrase I inhibitor. The assumption is confirmed by docking 5 into the active binding site of carbonic anhydrase, which shows it to have good binding affinities and to form stable complexes with the active residues of carbonic anhydrase I.

Vinylation of N-Heteroarenes through Addition/Elimination Reactions of Vinyl Selenones.

A new protocol for the synthesis of N-vinyl azoles using vinyl selenones and azoles in the presence of potassium hydroxide was developed. This reaction proceeded under mild and transition metal-free conditions through an addition/elimination cascade process. Both aromatic and aliphatic vinyl selenones and various mono-, bi- and tri-cyclic azoles can be tolerated and give terminal N-vinyl azoles in moderate to high yields. A plausible mechanism is also proposed.

Synthesis and Spectral Study of some New α, β-Unsaturated Carbonyl Compounds and Pyrazole Derivatives

This work includes the synthesis of some new pyrazole derivatives from the reaction of new a,b- unsaturated carbonyl derivatives with hydrazine hydrate. a,b- Unsaturated carbonyl derivatives which are prepared in several ways by reaction of hydrazide-hydrazone A2 with substituted aromatic aldehydes in the presence of triethylamine as a base, and also prepared by reaction of hydrazide-hydrazone A2 with phenylisothiocyanate and (ethyl chloro acetate or dimethyl sulfate) or A2 with carbon disulfide and (ethyl chloro acetate or dimethyl sulfate) in the presence of potassium hydroxide in dry dimethyl formamide. The structures of these new synthesized compounds were confirmed by physical and spectroscopic methods (FT-IR, 1H-NMR,13C-NMR).

Effect of alkaline activation on the structural characteristics of nanocomposites based on carbonized chitosan and Fe-Co bimetallic nanoparticles

Metal-carbon nanocomposites consisting of Fe-Co bimetallic nanoparticles uniformly dispersed in the carbon matrix were synthesized by pyrolysis of a precursor based on chitosan and metal salts in the temperature range 500-800°C. The change in the structural characteristics of the samples after activation in the presence of potassium hydroxide was studied. It was found that alkaline activation leads to an increase in the specific surface area of the nanocomposites up to 700 m2/g and in the size of metal nanoparticles, whereas the phase composition and morphology of the carbon support remain unchanged.

Novel Hybrid Composites Based on Polymers of Diphenyl-Amine-2-Carboxylic Acid and Highly Porous Activated IR-Pyrolyzed Polyacrylonitrile.

Hybrid composites based on electroactive polymers of diphenylamine-2-carboxylic acid (PDPAC) and highly porous carbon with a hierarchical pore structure were prepared for the first time. Activated IR-pyrolyzed polyacrylonitrile (IR-PAN-a), characterized by a highly developed surface, was chosen as a highly porous N-doped carbon component of the hybrid materials. IR-PAN-a was prepared using pyrolysis of polyacrylonitrile (PAN) in the presence of potassium hydroxide under IR radiation. Composite materials were obtained using oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) in the presence of IR-PAN-a both in an acidic and an alkaline medium. The composite materials were IR-heated to reduce the oxygen content and enhance their physical and chemical properties. The chemical structure, morphology, and electrical and thermal properties of the developed IR-PAN-a/PDPAC composites were investigated. The IR-PAN-a/PDPAC composites are thermally stable and electrically conductive. During the synthesis of the composites in an acidic medium, doping of the polymer component occurs, which makes the main contribution to the composite conductivity (1.3 × 10-5 S/cm). A sharp drop in the electrical conductivity of the IR-PAN-a/PDPACac-IR composites to 3.4 × 10-10 S/cm is associated with the removal of the dopant during IR heating. The IR-PAN-a/PDPACalk composites prepared before and after IR heating show a gradual increase in electrical conductivity by five orders of magnitude to 1.6 × 10-5 S/cm at 25-106 Hz. IR heating of the obtained materials leads to a significant increase in their thermal properties. The IR-heated composites lose half of their initial weight in an inert atmosphere at temperatures above 1000 °C, whereas for IR-PAN-a/PDPAC, the temperature range is 840-849 °C.

Testing of n-butanol and eucalyptus essential oil as additivities of cottonseed biodiesel-diesel blends

The B10 fuel blend in the presence (or absence) of n-butyl alcohol and eucalyptus essential oil additivities by the ASTM standards has been tested. As seen our results, these oxygenated compounds can be successfully used in B10 fuel blends as additives to improve exploitation properties. Methanol-based biodiesel has been synthesized by the transesterification reaction of technical cottonseed oil in the presence of potassium hydroxide, with a maximum yield of 64% at a molar ratio of oil to alcohol of 1:3, at 65°C. The oxidizing stability of the B10 fuel blends with (or without) additivities has been evaluated using the NMR spectroscopy method. Our experimental results demonstrated that investigated B10 fuel blend with oxygenated compounds has a high potential for diesel engines than B100 and petroleum diesel. The best results demonstrate the B10+n-Butanol fue

Synthesis, Characterization and Cytotoxicity Activity Study of Some Chalcones Derived from 2-(1,1-dimethyl-1,3-dihydro-2H-benzo[e]indol-2-ylidene)malonaldehyde

In this work, series of new chalcones derived from indole compounds were synthesized. In the first the compound 2-(1,1-dimethyl-1,3-dihydro-2H-benzo[e]indol-2-ylidene)malonaldehyde was synthesized from the reaction of 1,1,2-trimethyl-1H-benzo[e]indole with Phosphoryl chloride in in the presence of (DMF). Schiff base (C2) was prepared by reaction of 2-(1,1-dimethyl-1,3-dihydro-2H-benzo[e]indol-2-ylidene) malonaldehyde with 3-amino acetophenone and then the compounds (C3-C6) were synthesized by reacting compound (C2) with a different aryl aldehyde in the presence of potassium hydroxide. The chemical composition of the compounds was confirmed and characterized by spectroscopic techniques (FT-IR, 1H-NMR and13C-NMR). Target compounds with different concentrations were investigated for their cytotoxic activity against the human breast cancer cell line MCF7. The results showed that the compounds had promising cytotoxic activity against MCF7 cell line especially compound (2) which showed the highest inhibition at the rate of 100 µg/mL among the tested compounds at varied concentrations.

Improvement of gas hydrate-based CO2 capture from CH4/CO2 mixture using silica and modified silica nanoparticles in the presence of potassium hydroxide

Separation of CO2 gas from CO2/CH4 mixture (74 mol% of CH4 and 26 mol% of CO2) was investigated, experimentally using the gas hydrate formation method in a constant-volume vessel. Silica and (3-aminopropyl) teriethoxysilane (APTES) surface-modified silica nanoparticles in the presence of potassium hydroxide were employed as additives. The impacts of various parameters such as initial pressure, gas–liquid ratio, and nanoparticle concentration were studied on gas consumption, separation factor, and recovery factor of CO2 gas in the separation process. Experiments were performed at 277.15 K and two initial pressures of 3.0 and 4.0 MPa. The presence of silica had a positive effect on gas consumption, separation, and recovery factors. The optimum results are obtained for the nanofluids including silica and potassium hydroxide, which at best case improved the gas consumption, separation factor, and recovery factor by 36 %, 29 % and 38 % compared to the pure water, respectively. The optimum nanoparticle concentration was obtained to be 0.1 wt% Besides, as the gas–liquid ratio increased, the gas consumption value raised. However, the relative amount of gas consumption and the recovery factor decreased. While the gas consumption was a direct function of the initial pressure, the separation and recovery factors were inverse functions of that.

Antiproliferative and antimicrobial studies of novel organic-inorganic nanohybrids of ethyl 2-((5-methoxy-1H-benzo[d]imidazol-2-yl)thio)acetate (EMBIA) with TiO2 and ZnO

Ethyl-2-((5-methoxy-1H-benzo[d]imidazol-2-yl)thio)acetate (EMBIA) was synthesized by the reaction of ethylchloroacetate and 5-methoxy-2-mercaptobenzamidazole in the presence of potassium hydroxide. EMBIA was used to produce novel organic: inorganic nanohybrids with newly synthesized ZnO and TiO2 nanostructures and fully characterized using FTIR, SEM, EDX, XRD and TEM. Furthermore, the synthesized nanohybrids were used to check their antibacterial and antifungal activities against some normal and antibiotic resistance bacteria (E. faecalis VRE, E. faecalis, S. aureus, S. aureus MSSA, S. aureus MRSA, E. coli, E. coli ESBL, P. aeruginosa AGME, S. mutans, S. gordonii, A. actinomycetemcomitans) and fungi (C. albicans). Furthermore, these nanohybrids were used to check their anticancer activity against brain cancer cell lines, gynaecological cancer cell lines, colon cancer cell lines, in addition to lung, retinal, and skin normal cells were used to check the toxicity. The value of total growth inhibition (TGI) was 43.27 and 79.01 µg/ml for EMBIA and EMBIA-TiO2, while it was 4.29 µg/ml for the EMBIA-ZnO against normal cell lines. The TGI values against cancer cell lines of EMBIA and EMBIA-TiO2 were better than those reported for the reference compound 5-fluorouracil (5FU).

Constructing artificial solid electrolyte interphase by facile chemical reaction for stable lithium metal anodes

Lithium metal is considered one of the most promising anode materials because of its high theoretical capacity and the lowest electrode potential, but practical application is hampered by high reactivity and volume variation in circulation. As a key component, the artificial solid electrolyte interphase (SEI) is designed to effectively stabilize the lithium anode. Here, the chemical reaction between dimethyl sulfoxide (DMSO) and lithium is accelerated in the presence of potassium hydroxide (KOH). The sulfur-containing organic compounds, lithium sulfate (Li2SO4), lithium hydroxide (LiOH) and other favorable components are introduced into SEI, which enable the modified lithium metal anode to have lower interfacial impedance, higher lithium ion transference number, and more uniform Li-ion deposition. The assembled Li-Li symmetric battery realizes a stable cycle of more than 800 h at a current density of 0.5 mA cm−1 and an areal capacity density of 1 mAh cm−1. The full cell coupled with LiNi0.6Co0.2Mn0.2O2 (NCM622) still maintains 113 mAh g−1 discharge capacity with 63% capacity retention rate after 400 cycles at a current density of 0.5 C. The simple construction of artificial SEI strategy of this study provides an effective strategy for LMBs with superior electrochemical performance.

The effect of addition Ag and MnO2 nanoparticles in the hydrogen storage of ethyl 2-((5-methoxybenzo[d]thiazol-2-yl)thio)acetate (organic: Inorganic nanohybrids)

This research included the synthesis of ethyl2-(benzo[d]thiazol-2-ylthio)acetate (EBTA) by reacting 2-mercaptobenzothiazole with ethylchloroacetate in the presence of potassium hydroxide. The compound was characterized using 1HNMR and FTIR. This compound was used to prepare two of its organic: inorganic nanohybrids with nano-manganese oxide (EBTA-MnO2) and with nano-silver (EBTA-Ag). The resulting composites were characterized using FTIR, XRD, SEM, EDX and TEM. The measurements proved that the reaction occurred successfully through the one-step reaction. These compounds were used in the application of hydrogen storage, and the study proved that the addition of these nanomaterials gave a great ability to increase hydrogen storage. The results showed that the compounds (EBTA), (EBTA-Ag) and (EBTA-MnO2) gave 0.99, 3.63 and 4.05 wt% hydrogen storage capacity, respectively. Also the study showed that the nano-hybrid (EBTA-MnO2) gave more storage efficiency than (EBTA-Ag), because manganese oxide contains two oxygen atoms, which act as effective real stores to increase the capacity hydrogen storage.

Biological activity against breast cancer cells of iron(II), copper(II) & nickel(II) complexes with Di-m-bromobenzalcyclohexanone & dibenzalcyclohexanone - thiosemicarbazide schiff bases

The title work included synthesis of new symmetrical dibenzalcyclohexanone substituted with one bromine group at meta position of each benzene ring. The synthesised ketones were dibenzalcyclohexanone and di-m-bromobenzalcyclohexanone. Di-m-bromobenzalcyclohexanone was synthesised through the reaction of cyclohexanone with benzaldehyde in the presence of potassium hydroxide, as well as the preparation of ketones substituted with bromine at meta position from the reaction of cyclohexanone with the substituted benzaldehyde at meta position. The synthesised chalcones were characterized using different spectral and physical techniques. These ketones were used to prepare new Schiff bases by reacting the thiosemicarbazide compound with the previously mentioned un-substituted chalcone, first ligand, while the second ligand was prepared by reacting the meta-bromobenzalcyclohexanone with thiosemicarbazide. The synthesised ligands were bi-dentate ligand, according to this matter six metal complexes were synthesised through reacting two moles of Schiff bases with one mole of nickel (II), iron (II), & copper (II) chlorides. The novel metal complexes were characterized by different techniques such as 1H&13C-NMR and mass spectrometry (Mass Spectra) in addition to measurements of magnetic susceptibility and molar conductivity of the prepared complexes. Through spectroscopic studies and magnetic susceptibility, and physical properties, the shape of the prepared complexes were predicted.

Use of a horizontal ball mill to remediate per- and polyfluoroalkyl substances in soil

There is a need for destructive technologies for per- and polyfluoroalkyl substances (PFAS) in soil. While planetary ball mill have been shown successful degradation of PFAS, there are issues surrounding scale up (maximum size is typically 0.5 L cylinders). While having lower energy outputs, horizontal ball mills, for which scale up is not a limiting factor, already exist at commercial/industrial sizes from the mining, metallurgic and agricultural industries, which could be re-purposed. This study evaluated the effectiveness of horizontal ball mills in degrading perfluorooctanesulfonate (PFOS), 6:2 fluorotelomer sulfonate (6:2 FTSA), and aqueous film forming foam (AFFF) spiked on nepheline syenite sand. Horizontal ball milling was also applied to two different soil types (sand dominant and clay dominant) collected from a firefighting training area (FFTA). Liquid chromatography tandem mass spectrometry was used to track 21 target PFAS throughout the milling process. High-resolution accurate mass spectrometry was also used to identify the presence and degradation of 19 non-target fluorotelomer substances, including 6:2 fluorotelomer sulfonamido betaine (FtSaB), 7:3 fluorotelomer betaine (FtB), and 6:2 fluorotelomer thioether amido sulfonate (FtTAoS). In the presence of potassium hydroxide (KOH), used as a co-milling reagent, PFOS, 6:2 FTSA, and the non-target fluorotelomer substances in the AFFF were found to undergo upwards of 81%, 97%, and 100% degradation, respectively. Despite the inherent added complexity associated with field soils, better PFAS degradation was observed on the FFTA soils over the spiked NSS, and more specifically, on the FFTA clay over the FFTA sand. These results held through scale-up, going from the 1 L to the 25 L cylinders. The results of this study support further scale-up in preparation for on-site pilot tests.