Polymeric membranes based on cellulose acetate loaded with candle soot nanoparticles for water desalination

This study is concerned with modifying cellulose acetate (CA)/polyethylene glycol (PEG) membranes prepared via phase inversion technique in the presence of carbon nanoparticles; candle soot (CS) resulting from combusted candle. CS nanoparticles were analyzed via Fourier transform infrared spectroscopy and transmission electron microscopy. The developed membranes were characterized for their surface morphology, mechanical properties as well as thermal stability. CS nanoparticles contributed in improving the salt rejection % with a slight reduction in the water flux behavior. Employing the annealed cellulose acetate/polyethylene glycol membranes loaded with candle soot nanoparticles provides an adequate approach towards water desalination implementations.     

Development of a Chitosan/Nickel Phthalocyanine Composite Based Conductometric Micro-sensor for Methanol Detection

Thin-film composite of chitosan/nickel phthalocyanine (NiPc) was electrochemically deposited on the fingers of interdigitated gold electrodes, applying chronoamperometric polymerization technique. The presence of crystallized NiPc in the chitosan was confirmed by EDX and FTIR analysis. Acetone, ethanol, and methanol gas-sensing properties of the films prepared at optimum conditions were studied at atmospheric temperature, through differential measurements at an optimized frequency of 10 kHz, using a lock-in amplifier. The conductometric sensor presents the highest sensitivity of 60.2 μS.cm⁻¹(v/v) for methanol and 700 ppm as the limit of detection. For validation, the methanol content of a commercial rubbing alcohol was determined.     

Facile one-pot,three-component synthesis of novel bis(heterocycles) incorporating thieno[2,3-b]thiophenes via Michael addition reaction

A synthesis of novel series of bis(2-amino-3-cyano-4H-chromene), bis(2-amino-3-cyanopyrano[3,2-c]chromene), bis(6-amino-5-cyano-1,4-dihydropyrano[2,3-c]pyrazole), and bis(2,7-diamino-3,4,6-tricyanopyrazolo[1,5-a]pyridine) derivatives linked to thieno[2,3-b]thiophene core via ether or ester linkages was reported. The formation of the target compounds presumably proceeds through a three component reaction of the appropriate bis(aldehyde) with 2 M of each of malononitrile and the corresponding active methylene compounds namely; dimedone, 4-hydroxycoumarine, 5-methyl-2,4-dihydro-3H-pyrazol-3-one, or cyanomethylpyrazole in dioxane at reflux in the presence of piperdine as a basic catalyst. The chemical structures of the new compounds were elucidated by several spectral tools.     

Solid-state ion exchange of ammonium heptamolybdate tetrahydrate into ZSM-5 zeolite

Journal of Thermal Analysis and Calorimetry - Thermal decomposition (2 K min?1) of ammonium heptamolybdate tetrahydrate, performed between room temperature and...     

Arylhydrazonals as the aldehyde component in Baylis-Hillman reactions

Arylhydrazonals were added to acrylonitrile or methyl vinyl ketone in the presence of DABCO or benzotriazole to yield the intermediate Baylis-Hillman adduct that cyclized under the reaction conditions with water elimination to yield dihydropyridazines. A pyridazine reacted with DMAD to yield a pyridine via a [4+2] Diels-Alder addition followed by retro Diels-Alder elimination of methylene aniline. Two pyridazines were condensed with DMFDMA to yield the corresponding enaminones that reacted with NH₂NH₂ to afford the pyrazolylpyridazines.     

Utility of 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile in heterocyclic synthesis

Pyrazolo[4,3‐d]pyrimidines, pyrazolo[4,3‐d]triazolino[4,3‐a]pyrimidines, 3‐(2‐thiazolyl)thiophenes, thiazolo[3,2‐a]pyridine and pyrazolo[1,5‐a]pyrimidines were synthesized from 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation and alternative synthesis route whenever possible.     

Electrochemical Affinity Sensors Using Field Effect Transducer Devices for Chemical Analysis

The review presents advances and main challenges of the affinity sensors based on field- effect transistors published during the last five years. The different nanomaterial-based field-effect transistors are classified according to the nature of the nanomaterials, beginning by silicon, the “gold-standard” semiconductor, the gallium nitride semiconductor, the organic semiconductors, the silicon nanowires, the inorganic nanomaterials, the carbon nanotubes and the graphene. Due to its exceptional electrical properties, the main works are devoted to graphene. The obtained analytical performances for the detection of biomarkers, of DNA sequences and of miRNA are listed. The relation between the operational conditions - nature of the nanomaterials, procedure of preparation, choice of the receptor molecule, method of immobilization – and the analytical performance are discussed. The perspective of industrialization of these affinity sensors based on field-effect transistors is discussed.     

Insecticidal effect of <Emphasis Type="Italic">Mentha pulegium</Emphasis> L. and <Emphasis Type="Italic">Mentha suaveolens</Emphasis> Ehrh. hydrosols against a pest of citrus, <Emphasis Type="Italic">Toxoptera aurantii</Emphasis> (Aphididae)

Essential oils proved their efficiency as natural insecticides to fight many pests of stored products and crops whereas the hydrosols have not been evaluated yet. The objective of this work is to assess the insecticidal effect of hydrosols extracted from Mentha suaveolens Ehrh. and Mentha pulegium L. toward an insect pest of citrus, Toxoptera aurantii (Homoptera, Aphididae). The extraction of hydrosols was carried out by hydro-distillation using Clevenger apparatus and then the chemical composition was identified by gas chromatography coupled with mass spectrometry. The chemical composition of two hydrosols revealed the abundance of hydrophilic and oxygenated compounds as piperitenone oxide and carvacrol. Different concentrations of each hydrosol were separately diluted in distilled water and applied topically to aphids. The results of this investigation have shown a high insecticidal effect, and the M. suaveolens hydrosol is more effective against citrus pests than that of M. pulegium L. Consequently, these natural compounds can be used in the management of aphids on citrus.     

A Convenient Synthesis of Some New 1,3,4‐Thiadiazoles,Thiazoles, Pyrazolo[1,5‐a]pyrimidines,Pyrazolo[5,1‐c]triazine,and Thieno[3,2‐d]pyrimidines Containing 5‐Bromobenzofuran Moiety

1,3,4‐Thiadiazoles, pyrazolo[1,5‐a]pyrimidines, pyrazolo[5,1‐c]triazine, and thieno[3,2‐d]pyrimidines were synthesized from 1‐(5‐bromobenzofuran‐2‐yl)ethanone. The structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation, and alternative synthesis route whenever possible.     

Useful Precursors for Synthesis of Some New Azolo[3,4‐d]pyridiazines,Azolo[1,5‐a]pyrimidines,Azolo[5,1‐c]triazines,Pyrazoles, and Benzo[b][l,4]diazepine

Pyrazolo[3,4‐d]pyridazines, isoxazolo[3,4‐d]pyridazines, azolo[1,5‐a]pyrimidines, azolo[5,1‐c]triazines, pyrazoles, and benzo[b][l,4]diazepine were synthesized from the appropriate hydrazonoyl halides, hydroximoyl halides, heterocyclic amines, diazotized heterocyclic amines, arenediazonium chlorides, and o‐phenylenediamines with appropriate of sodium 3‐(5‐bromobenzofuran‐2‐yl)‐3‐oxoprop‐1‐en‐1‐olate or 1‐(5‐bromobenzofuran‐2‐yl)‐3‐(dimethylamino)prop‐2‐en‐1‐one. The newly synthesized compounds were elucidated by elemental analyses, spectral data, and alternative synthesis whenever possible.