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This paper assesses the fluctuation of relative response factors (RRFs) for the quality control of alcoholic products by GC–MS, using two internal standard (IS) methods, namely, a commonly used IS method using 1-pentanol, and "Ethanol as IS" method. To evaluate the variation of calibration factors values the Taguchi designed experiment was used. Matrix composition, volatile compounds concentrations, injected volume of the sample, GC injector temperature and split ratio were the five selected control factors. Within the experiment each of these control factors took one from three possible values to create 27 various measuring conditions. The results of the experiment revealed, that relative standard deviations of RRFs within all 27 measuring conditions were 7.3 ± 4.1% for the 1-pentanol method and 36.3 ± 3.5% for the ethanol method. The possible reasons of calibration factors variation were also discussed. [ABSTRACT FROM AUTHOR]

The monitoring of food contaminants is of interests to both food regulatory bodies and the consumers. This literature review covers polycyclic aromatic hydrocarbons (PAHs) with regard to their background, sources of exposures, and occurrence in food and environment as well as health hazards. Furthermore, analytical methods focusing on the analysis of PAHs in tea, coffee, milk, and alcoholic samples for the last 16 years are presented. Numerous experimental methods have been developed aiming to obtain better limits of detections (LODs) and percent recoveries as well as to reduce solvent consumption and laborious work. These include information such as the selected PAHs analyzed, food matrix of PAHs, methods of extraction, cleanup procedure, LOD, limits of quantitation (LOQ), and percent recovery. For the analysis of tea, coffee, milk, and alcoholic samples, a majority of the research papers focused on the 16 US Environmental Protection Agency PAHs, while PAH4, PAH8, and methylated PAHs were also of interests. Extraction methods range from the classic Soxhlet extraction and liquid–liquid extraction to newer methods such as QuEChERS, dispersive solid-phase microextraction, and magnetic solid-phase extraction. The cleanup methods involved mainly the use of column chromatography and SPE filled with either silica or Florisil adsorbents. Gas chromatography and liquid chromatography coupled with mass spectrometry or fluorescence detectors are the main analytical instruments used. A majority of the selected combined methods used are able to achieve LODs and percent recoveries in the ranges of 0.01–5 ug/kg and 70–110%, respectively, for the analysis of tea, coffee, milk, and alcoholic samples. [ABSTRACT FROM AUTHOR]

In this paper, the reaction of [Ir(COD)Cl]2 with in situ prepared Ag–N-heterocyclic carbene (NHC) complexes yields a series of [IrCl(COD)(NHC)] complexes. All compounds were fully characterized by 1H NMR, 13C NMR, and FT–IR spectroscopy. The manuscript focused on the preparation of new Ir–NHC complexes, characterization and catalytic behavior. A series of hydrogenation transfer reactions were performed to reveal the effects of the Ir–NHC complexes. The new Ir–NHC complexes of benzimidazole-2-ylidene are effective catalysts for the transfer of hydrogenation of different ketones, using i-PrOH as the source of hydrogen in the presence of KOH. The reactions were conducted at a substrate/catalyst/base (S/C/base) molar ratio of 1:0.001:2. Although all of the complexes are active catalysts for the transfer hydrogenation of ketones, moderate yields were obtained with acetylnaphthalene and conversion was not observed with very substituted ketones such as 2′,3′,4′,5′,6′-pentamethylacetophenone. It was observed that for transfer hydrogenation reactions Ir–NHC catalysts were more active, compared to Ru–NHC catalyzed studies performed by our team. [ABSTRACT FROM AUTHOR]

Growing environmental concerns worldwide encourage industrial sectors to transition from fossil to bio-based products. However, deciding where to invest R&D resources is critical since many different bio-based products can be economically competitive. As one of the biggest biomass producers, Brazil plays an important role in this transition as a feedstock supplier. In this work, the Delphi technique was employed to identify Brazil's challenges and opportunities for the local production of renewable short-chain acids and alcohols in the bioeconomy context. The results indicate that optimization and development of the downstream processes to reduce costs are the main challenges for traditional renewables and drop-in chemicals production. For new renewable chemicals, the main challenge is to demonstrate the economic potential of these compounds, as they do not have a pre-established market and depend on proving their performance. Lactic acid, acrylic acid, levulinic acid, ethanol, isobutanol, and polyols are the most locally demanded products from biomass. This work also shows that Brazilian perspectives on bio-based alcohols and carboxylic acids are aligned with worldwide demands. This study successfully summarizes the view of specialists on technological developments, challenges, and limitations to the bio-based process in Brazil. [ABSTRACT FROM AUTHOR]

Abstract: This paper studied the effect of alcohols on simultaneous esterification and alkylation reactions designed for the upgrading of bio-oil, and the separation of upgraded oil. The upgrading of bio-oil was performed in an autoclave with Amberlyst-36 as the catalyst, and methanol, ethanol, and n-butanol as the alcoholic solvents. The separation of various chemical components, such as unreacted solvents, water phase, extraction phase, and high value-added chemicals, in the upgraded oil were realized via distillation, at 80-90 °C (at 0.01 MPa) vacuum distillation and an extraction process. The results showed that, the simultaneous esterification and alkylation reactions for the upgrading of bio-oil not only restrained the acetylation reaction of aldehydes, which increased the relative contents of stable ethers, but also enhanced the oil soluble components of the upgraded bio-oil. After separation, the high value-added chemical, namely methyl-α-D-glucopyranoside, was obtained with 5.39 wt.% yield and a relative content of 88.9% (sugar phase). The results from this work also showed that this novel method was quite a promising technique for upgrading bio-oil together with the separation of the high value-added chemical.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Abstract: Malodorous odors, by definition, are unpleasant, irritating smells being a mixture of volatile chemical compounds that can be sensed at low concentrations. Due to the increasing problem of odor nuisance associated with odor sensations, and thus the need to remove them from the air, deodorization techniques are commonly used. Biofiltration is one of the methods of reducing odorants in the air stream. In the paper, the possibility of using an electronic nose as an alternative method to gas chromatography for the online monitoring and evaluation of efficiency of the n-butanol vapors biofiltration process in a transient state was investigated. Three calibration models were used in the research, i.e., multiple linear regression, principal component regression, and partial least-square regression. The obtained results were compared with the theoretical values.Graphical abstract: [ABSTRACT FROM AUTHOR]

The paper presents chromatographic-mass spectrometric data on the individual composition of organic compounds in sapropel-like deposits of lakes in the steppe, forest-steppe, and three taiga natural climatic zones (NCZ) in Khakassia and western Siberia. Data on the individual composition of n-alkanes, carboxylic acids and their esters, thiophenes, phytol, phytone, steroids, and di- and triterpenoids and on their distribution in the sediments show systematic variations in the composition of the organic matter (OM) with increasing ambient temperature and the aridity of the climate. The concentrations of all groups of the compounds in lacustrine sediments decrease southward, and simultaneously esters with long (up to С) alkyl substituents appear. The concentrations of oxygen-bearing compounds increase among the acyclic structures and triterpenoids, as also do the concentrations of structures ketonic substituents among the steroids. The dominance of the carboxylic acids and their esters by high molecular weight homologues gives way to the dominance of palmic acid and its derivatives. Among n-alkanes, the dominance of С and С hydrocarbons typical of terrestrial plants gives way to a higher percentage of homologues С-С (macrophytes) and С (herbaceous plants). Among the tocopheroles, the concentration of the oxidized form of α-tocopherol (acetate) increases. [ABSTRACT FROM AUTHOR]

The present paper reports on the use of CeO2 materials supported palladium chloride catalyst for selectively oxidising organic alcohols into aldehydes. Spherical, microsized rod-shaped and spindle-like CeO2 particles are synthesised and characterised by SEM. The catalysts are prepared by loading palladium chloride onto the CeO2 support matrix. A complete characterization of the catalysts is performed. The activity of catalysts is studied by the selective oxidation of various alcohols. The results show that (1) the catalytic activities prepared by spherical cerium are superior to the catalysts prepared by spindle-like or rod-shaped cerium and (2) the catalyst PdCl2/CeO2 (nanospheres) show good activity, high yield, and good stability. [ABSTRACT FROM AUTHOR]

Alternative fuels in spark-ignition engines significantly reduce engine exhaust emissions and improve fuel efficiency. This research investigates the performance of a multicylinder SI engine using 10%, 20% (ethanol, methanol, methyl acetate), and 100% compressed biomethane gas (CBG) as alternative fuels. Engine performance parameters (BTE, ITE, ME, BP), BSFC, ISFC, FF, combustion phenomenon (cylinder pressure, crank angle, cylinder volume, mass fraction burned, net heat release, mean gas temperature, cumulative heat release, rate of pressure rise), and emission characteristics (HC, CO, CO2, NOx) are measured. CBG achieved a maximum BTE of 23.33% compared to all other fuels. Minimum fuel consumption rate of 1.72 kg/h at maximum rpm achieved BSFC value of 0.44 kg/kWh and ISFC value of 0.261 kg/kWh. The highest cylinder pressure of 6.79 bar was achieved in the G90M10 with a cylinder volume of 48.58 cc. NHR of 3.08 j/deg was found in the G80M20 at a crank angle of 376°, and the maximum MGT was 390.20 °C in the G80E20. The highest CHR values of 0.12 kJ at crank angles of 432°, 420°, 422°, and 427° were achieved in the G100, CBG, G80E20, and G90E10. G90M10 reached a maximum value of 0.14 bar/degree of rate of pressure rise at a crank angle of 374°. Average minimum emission gas was found in CBG at a minimum and maximum RPM, indicating that CBG gives the best emission result with engine performance compared to all alternative fuels. [ABSTRACT FROM AUTHOR]

This work reports the effect of four different physicochemical pretreatments (acidic, thermal, acidic-thermal, and thermal-acidic) on an anaerobic inoculum aiming at alcohols production, using acetate and butyrate as carbon sources and hydrogen as co-substrate. Pretreatments were carried out to select microbial communities more able to use hydrogen to metabolize volatile fatty acids into their respective alcohols. Experiments were conducted in single batches using acetate and butyrate as substrates at 30 °C and with a pressurized headspace of pure H2 at 2.15 atm (218.2 MPa). Thermal and acidic-thermal pretreatments lead to higher production of both ethanol and butanol, indicating that these pretreatments successfully selected communities more suitable for acetate and butyrate solventogenesis. Kinetics modelling shows that the highest attainable concentrations of ethanol and butanol produced were 122 mg L−1 and 97 mg L−1 for the thermal pretreatment (after 17.5 days) and 87 mg L−1 and 143 mg L−1 for the acidic-thermal pretreatment (after 18.9 days). Process thermodynamics indicated that high H2 partial pressure favoured solventogenic metabolic pathways. Sequencing data showed that both thermal and acidic-thermal pretreatments selected mainly the bacterial genera Pseudomonas, Brevundimonas, and Clostridium. Acidic-thermal pretreatment selected a bacterial community more adapted to the conversion of acetate and butyrate into ethanol and butanol, respectively. Thermal-acidic pretreatment was unstable, showing significant variability between replicates. Acidic pretreatment showed the lowest alcohol production. [ABSTRACT FROM AUTHOR]

The reaction involving benzyl alcohol or benzyl halide and urea, conducted within a mixture comprising choline chloride and aluminium nitrate ionic liquid as the solvent, leads to the synthesis of N-monosubstituted urea products. The reaction demonstrates notable to exceptional yields for various derivatives of benzyl alcohols and benzyl halides under the specified reaction conditions. When benzyl halides and benzyl alcohol undergo reactions with urea in the presence of the prepared ionic liquid, a sole selective pathway is observed, resulting in a considerable yield of N-monosubstituted urea products. This approach offers several advantages, including reaction selectivity, high product efficiency, facile separability of products, the environmentally benign nature of the solvent, and the omission of expensive and hazardous catalysts. These attributes underscore the significance of such pioneering reactions. Due to the markedly polar attributes and insolubility of the resulting products in water, facile separation from the reaction milieu is facilitated through the introduction of water into the reaction mixture. Consequently, this specific ionic liquid methodology provides an uncomplicated and selective avenue for the synthesis of compounds possessing noteworthy pharmaceutical and industrial utility. [ABSTRACT FROM AUTHOR]

An universal catalytic system 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl/KI/pyridine base for the conversion of alcohols into carbonyl compounds and derivatives of carboxylic acids is developed. The use of pyridine, 2,6-lutidine or collidine made it possible to obtain carbonyl compounds (in yield up to 100%) after passing a charge of 2–2.2 F. In the presence of pyridine, aliphatic alcohols are converted to esters (in yield up to 35%) after passing 4 F. Acid anhydrides (in yield up to 80%) are formed using 2,6-lutidine or collidine after passing 5–6 F. Nitriles were obtained (in yield up to 99%) in the presence of 2,6‑lutidine and a source of nitrogen after passing 4–4.5 F. [ABSTRACT FROM AUTHOR]

Dehydrogenation of primary or secondary alcohols promoted by transition metal catalysts is the key initial step in many transformations involving alcohols. Besides the formation of value-added carbonyl products, the liberation of dihydrogen has been envisioned as a potential source of energy, or as a useful reagent for further metal-catalyzed hydrogenation of unsaturated substrates. The history of alcohol dehydrogenation and its applications in various types of transformations initiated with noble transition metal and continued with 3d base metal catalysts are reported in this chapter. [ABSTRACT FROM AUTHOR]

For the first time, the beneficial "Ethanol as Internal Standard (IS)" method developed for the analysis of alcoholic products was tested in headspace mode of solid-phase microextraction gas chromatography with flame ionization detector (SPME-GC/FID) and compared with the traditional IS method. The extraction and separation conditions were optimized for the analysis of 10 volatile congeners prescribed in European legislation: acetaldehyde, methyl acetate, ethyl acetate, methanol, butan-2-ol, propan-1-ol, 2-methylpropan-1-ol (isobutanol), butan-1-ol, 1,1-diethoxyethane (acetal), and 3-methylbutan-1-ol (isoamylol). To evaluate the accuracy of the compared methods, three real alcoholic product samples with ethanol content of 20%, 40%, and 80% v/v were spiked with gravimetrically prepared standard solutions to calculate recoveries. The obtained data indicates that the suggested method can be employed as a robust and accurate tool for SPME analysis of alcoholic products with low ethanol content, such as wines. It was also observed that an increase in ethanol content in the matrix affects the accuracy of the "Ethanol as IS" method, potentially due to non-linearity of analyte extraction. However, in the case of wine sample, the "Ethanol as IS" method showed significantly better results compared to the traditional approach. The precision of the suggested method, evaluated using relative standard deviations (RSD) of obtained concentrations was found to be comparable to that of the traditional method. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the use of ethanol/gasoline fuel blends in a single-cylinder spark-ignition engine with energy, exergy, exergoeconomic and exergoenvironmental analysis. Test fuels (G100, E10, E20, E30, E40, E50, and E100) prepared by adding ethanol obtained from agricultural products to gasoline at different ratios were utilized in experimental studies. Thermodynamic analyses were carried out using the performance and emission data obtained from the engine tests. Thermal efficiency and exergy efficiencies were computed with energy and exergy analyses. The highest efficiencies were acquired at 2500 rpm for all fuels. The exergy efficiency of G100, E20 and E40 fuels at this engine speed is 17.13%, 15.81% and 14.62%, respectively. Furthermore, cost of engine shaft work in exergoeconomic analysis and environmental cost of shaft work in exergoenvironmental analysis were found in study. When an engine speed was 2500 rpm in E50 fuel, the cost of shaft work was 74.21 $ MJ−1, and the environmental cost of shaft work was 59.07 $ GJ−1. Moreover, exergoeconomic factor and exergoenvironmental factor values of fuel blends were computed. It was revealed that increased ethanol ratio in fuel blends increased economic and environmental costs. In terms of economy and environment, it can be considered appropriate that the ethanol ratio in fuel blends is between 30 and 40%. If ethanol is used higher than these rates, costs increase and fuels become uneconomical. [ABSTRACT FROM AUTHOR]

Noble metal catalysts are generally expensive, and thus, abundant 3d metals recently received significant attention as catalysts in catalytic hydrogenation. Mn catalysts are widely applied in transfer hydrogenations, but the reported catalyst loadings remain up to three orders of magnitude higher than noble metals. Thus, catalyst consumption should be overcome before 3d metal catalytic systems may be utilized practically in industry. Here, a catalytic system based on novel, scalable triazole N5-ligands coordinated to Mn is presented for use in transfer hydrogenations. Based on pre-activation via dehydrohalogenation, an unprecedented, efficient catalytic system operating via synergistic H-bond auxiliary activation was established. The Mn catalysts are practical at metal concentrations 0.0001 mol%, generating alcohol with turnover number (TON) up to 857,200, thus approaching loadings more conventionally observed in precious-metal-based systems. Notably, using this protocol, several pharmaceuticals may be easily synthesized in one pot. [ABSTRACT FROM AUTHOR]

A synergistic effect of cyclic ketals in compositions with lower alcohols has been revealed for the first time while adding those ketals to alcohol-containing gasoline. By using model oxidation reactions of ketals and their structural analogs, 1,3-benzodioxolanes, in protic media, the synergistic effect was rationalized assuming the formation of ketal–alcohol complexes possessing surfactant properties, which give rise to hydrated supramolecular structures around them. Deactivation of hot radicals with the transition from the explosive combustion mode to stationary combustion inside these structures is more effective than in the bulk medium. Such structuring effect is general for the behavior of ketals in hydrophobic–hydrophilic systems, including biological ones. This conclusion has been confirmed by studying the activity of cyclic ketals in compositions with antibacterial agents, as well as with alcohols and carboxylic acids. [ABSTRACT FROM AUTHOR]

Three rhodium-containing catalytic systems active in tandem hydroformylation/hydrogenation of unsaturated substrates were developed based on polyethyleneimine (PEI): a homogeneous system with distillation of the product; a biphasic system with segregation of the product and catalyst into a non-polar phase and a polar phase, respectively; and a solid catalyst prepared from PEI and (3-chloropropyl)triethoxysilane with its centrifugation from the product mixture. All the systems were shown to be reusable over multiple cycles in hydroformylation/hydrogenation, with the catalytic activity being partially sustained in both steps of the tandem process. Methylation of PEI (or its NH and NH2 moieties in the case of solid material) was found to be critical for the catalytic activity in hydroformylation. [ABSTRACT FROM AUTHOR]

The study investigates tert-butoxy alkanols (otherwise defined as polyol tert-butyl ethers) that have vicinal tert-butoxy and hydroxy groups in their molecules from the perspective of their usability as oxygenated additives for motor gasoline. A series of propylene glycol mono-tert-butyl ether (PTBE) and glycerol di-tert-butyl ether (di-GTBE) samples were prepared: PTBE by direct acid-catalytic alkylation of diols with tert-butanol, and di-GTBE by alkylation of epichlorohydrin. Adding PTBE and di-GTBE to base motor gasoline was found to improve its antiknock performance: the average blending research octane number to blending motor octane number ratios (bRON/bMON) equaled 120/111 and 124/104 for PTBE and di-GTBE, respectively. Furthermore, the effects of the ether additives on the properties of ethanol-blended base gasoline were characterized. Finally, the study describes the effect of polyol tert-butyl ether additives on the cloud point depression of ethanol-blended gasoline (low-temperature phase stabilization) and demonstrates a positive synergistic effect of adding the ethers mixed with ethanol. [ABSTRACT FROM AUTHOR]

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Composites not only maintain the advantages of each component, but also achieve synergistic effects by complementing and combining the properties of each component, which cannot be achieved by a single component. In this work, Pdx-Auy/MXene (Ti3C2Tx) nanocomposites were prepared facilely by a one-pot method, and their composite structure was optimized. The molar ratio of the metal precursor (Pd2+/Au3+) plays a key role in the formation of the Pd-Au nanostructure. Electrocatalytic experiments demonstrate that the optimal Pd0.5-Au1.5/MXene sample possesses superior electrocatalytic activity and stability towards the oxidation reaction of alcohols in alkaline medium. Specifically, the Pd0.5-Au1.5/MXene shows oxidation peak current density of 63.1 mA mg−1metal, 72.5 mA mg−1metal and 189.1 mA mg−1metal for methanol, ethanol, and ethylene glycol, respectively, being 2.8, 2.1, and 1.2 times higher than those of the commercial Pd/C catalyst. The enhanced electrocatalytic performance of the Pd0.5-Au1.5/MXene catalyst can be ascribed to the high dispersity of Pd0.5-Au1.5 nanoparticles and the synergistic effect between the metal nanoparticles and MXene. This work may be helpful for the fundamental study of noble-metal-based electrocatalysts for direct alcohol fuel cells. [ABSTRACT FROM AUTHOR]

This work deals with catalytic activity of tetrabutylammonium decatungstate(VI) in the oxidation of selected alcohols with hydrogen peroxide as an oxidant using 1,2-dichloroethane/water or acetonitrile/water as a solvent system. Different forms of heating were compared. The highest conversions of substrates were achieved in the two phase system acetonitrile/water using microwave irradiation combined with elevated pressure. Finally, optimum parameters for these reactions in a microwave pressurised reactor were established and discussed. [ABSTRACT FROM AUTHOR]

A simple method for N-alkylation of 1,2-diaminoethane with different alcohols in a fixed-bed reactor using cheap CuO-NiO/ γ-AlO as the catalyst has been developed. The present catalytic system was applicable in the N-alkylation of 1,2-diaminoethane with both primary and secondary alcohols. Mono- N-alkylation of 1,2-diaminoethane with low-carbon alcohols resulted in high yields; the yields of tetra- N-alkylation of 1,2-diaminoethane with low-carbon alcohols declined markedly with the increase of the molecular volume of alcohols. [ABSTRACT FROM AUTHOR]

The effect of the addition of different proportions of silver (Ag) nanoparticles and alcohols in milk scum oil methyl ester on the performance of engine and emission are studied. B20 blend is added with 5% of ethanol, n-butanol, and iso-butanol as ternary additives for the experimental analysis from no load to full load. Furthermore, at a fixed load, operating conditions such as injection pressure (12 and 15 bar) and injection timing (23° and 26°) are varied without and with the addition of 0.8 vol% of Ag (silver) nanoparticles to the fuel blends. Also, the concentrations of Ag nanoparticles are increased from 0.2 to 1 vol% and comparisons are made with diesel and B60 blend. Mathematical models are developed for selected features of engine performance which fits with the experimental values for the purpose of optimization using the Dragon fly algorithm (DA) by considering these models as the objective functions. The concentration of nanoparticles lowers the BSFC significantly and helps in reducing the emission with an increased percentage. Using full biodiesel, 16.6% reduction in BTE was obtained, while use of alcohols prevented this reduction approximately by 5%. A highest of 4.6% improvement was obtained with the addition of Ag nanoparticles. 4.5% reduction in HC and 13% in NOx emission using nanoparticles are obtained. The DA algorithm provided the same optimized value at the end of 30 iterations in different cycles of execution. Nanoparticle addition and use of pressure in the range of 20 bar gives the lowest emission from the engine. [ABSTRACT FROM AUTHOR]

Binary blends of ethanol-diesel, n-butanol-diesel, ethanol-biodiesel, and n-butanol-biodiesel have been analyzed with terahertz time-domain spectroscopy in a full range of concentrations and at room temperature. The real and imaginary parts of the complex dielectric constant of the blends were obtained from the spectra and fitted to the Debye model at low volume concentrations (up to 7.5% for ethanol in diesel and up to 20% for butanol in diesel, ethanol in biodiesel, and butanol in biodiesel blends), considering the number of relaxation processes recommended in the literature for each pure component (single for diesel, double for biodiesel, and triple for alcohols). The results indicate that the faster relaxation time in low alcohol mixtures is longer than in pure alcohols. This relaxation time increases as the alcohol content increases. The excess of the real and of imaginary parts of the dielectric constant were individually determined. The analysis of such excess and of its different contributions (volume, contrast, and interactions) suggests that the intermolecular interactions between the different components of the blends dominate the relaxation dynamics in each pseudo-binary system. Ethanol was found to move blends further away from ideal behavior than n-butanol. In fact, these latter blends showed the most ideal behavior, suggesting that the length of the alcohol carbon chain plays an important role. This information allows a possible link between the nonlinear behavior of the physicochemical properties of the blends (e.g., viscosity and surface tension) and the molecular interactions between their constituent molecules. This relation could have direct application for monitoring the fuel composition and quality in the vehicle control systems. [ABSTRACT FROM AUTHOR]

The efficiency of essential oil depends upon the chemical nature, composition, and the relative proportion of its functional groups. In some case, individual compounds can exhibit a pertinent effect than do the essential oils. To underline their efficiency according to their chemical structure, five cyclic and acyclic alcohols were tested in vitro for their potential insecticidal and repellent activities against Tribolium castaneum (Herbst). The ability to repel more than 95% was observed in all tested compounds from 15 min to 10 h, except for eugenol that exhibited the weakest effect. Fumigant bioassay showed that the five alcohols applied separately caused significant insect mortality that exceeds 60% at 400 μL/L air. The lowest median lethal dose, LC50 = 18.24 μL/L was observed with citronellol. PCA analysis revealed that the acyclic alcohols showed stronger toxicity compared to the cyclic ones. Moreover, the combined effect of these alcohols was lower than individual ones in all tested combinations. According to the outcome of this study, acyclic alcohols might be more effective in reducing stored grain Tribolium infestation than cyclic ones as a single compound. The knowledge of the degree of efficiency of each chemical group gives the possibility to create artificial combinations of different constituents for the development of more effective eco-friendly control agents. [ABSTRACT FROM AUTHOR]

It is found that the thickness of aluminum oxide (Al2O3) film forming in distilled water linearly increases during 2000 s high-voltage anodization and that its electroluminescence (EL) is reliably detected at the Al2O3 film thickness of 120 nm. It is shown that Al2O3 electrolytically formed in distilled water and its deuterium-containing analogue—deuterium water can have an ordered cellular-nanoporous structure identical to the structure formed in aqueous solutions of electrolytes. At the same time, it is found that the existence of this oxide structure is not a necessary condition for its EL. The EL spectra of Al2O3 in distilled and deuterium water, as well as in water-like electrolytes (ethylene glycol, N,N-dimethylethanolamine, and isopentanol) are recorded for the first time. Considerable discrepancies in the luminescence of aluminum oxide in water and aforementioned alcohols are observed in the range of 400–700 nm. The short-wavelength EL component (at a wavelength near 440 nm) dominates in the EL spectra in the first two liquids, and the long-wavelength component peaking at 625 nm is dominant in the other three cases. Both the luminescence spectral composition and intensity in individual spectral ranges were observed to vary during aluminum anodization. [ABSTRACT FROM AUTHOR]

The aerobic oxidation of monoalcohols and diols to acetals is an important academic and industrial challenge for the production of fine chemicals and intermediates. The existing methods usually rely on a two-step process in which alcohols are first oxidized to aldehydes over metal catalysts (Ru, Pt, Pd) and then acetalized using acids. Due to the instability of aldehydes, how to avoid over-oxidation to their respective carboxylic acids and esters is a long-standing challenge. For this reason, certain non-conjugated dialdehydes have never been successfully produced from diol oxidation. Hereby we report a Ru@metal-organic framework (MOF) tandem catalyst containing ultra-fine Ru nanoparticles (< 2 nm) for direct alcohol to acetal conversion of monoalcohol and diols with no formation of carboxylic acids. Mechanistic study reveals that the presence of Lewis acid sites in the MOF work in concert with Ru active sites to promptly convert aldehydes to acetals thereby effectively suppressing the formation of over-oxidation byproducts. [ABSTRACT FROM AUTHOR]

In this study, periodic mesoporous organosilica containing bridges with N-sulfonic acid groups (SA-PMO), was easily prepared in two steps: (i) preparation of periodic mesoporous organosilica containing amine-bridges (AM-PMO) via co-condensation of bis[3-(trimethoxysilyl)propyl] amine and tetraethoxysilane and (ii) functionalization of AM-PMO with sulfonic acid. The formation and morphology of the reagent were confirmed by N2 adsorption-desorption isotherms, pH measurement, X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared FT-IR analysis. After identification, the catalytic ability of this reagent was investigated in the formylation of amines and alcohols using formic acid. Eco-friendly protocol, excellent yields, short reaction times, reusability of the catalyst and easy and quick isolation of the products are the main advantages of the presented method. [ABSTRACT FROM AUTHOR]

Novel biodegradable nanocomposite membranes were prepared by incorporating different concentrations (2, 4 and 6 wt%) of graphene oxide (GO) as a nanoadditive into a blend of sodium alginate/poly(ε-caprolactone) at ratio of 3:1 (SA:PCL) on the basis of solution-casting method and were then used for dehydration of a series of alcohols (methanol, ethanol and isopropanol) through pervaporation. The effects of feed composition, GO content and various alcohols on pervaporation performance were investigated. In addition, the swelling behaviors of SA/PCL/GO nanocomposite membranes were measured. All membranes were water selective, and the permeation rate increased with raising the GO content. The presence of GO having the functional groups increased the hydrophilicity of the SA/PCL blend polymer matrix, which resulted in the formation of a higher flux to water molecules. The best separation performance was achieved for the SA/PCL/GO-6 nanocomposite membrane containing 6 wt% GO with isopropanol–water feed at 30 °C. An enhancement in water concentration from 20 to 80 wt% increased the flux values from 506 to 779 g/m2 h. Likewise, an increase in feed water composition in the case of ethanol–water and methanol–water mixtures increased the flux values from 461 to 757 g/m2 h and from 298 to 569 g/m2 h, respectively. However, the separation factor of water for all membranes decreased with the increase in feed concentration. Pervaporation dehydration of aqueous isopropanol mixtures also proceeded easier than that of aqueous ethanol and methanol mixtures due to the larger molecular size of isopropanol. High dehydration performance of alcohol–water mixtures demonstrated the utility of these membranes for use in solvent dehydration application with higher efficiency. [ABSTRACT FROM AUTHOR]

Pulsed field gradient NMR diffusion measurements provide a non-invasive measure of the mass transport (self-diffusion) characteristics of liquids confined to porous catalyst materials. Here we explore the ability of this technique to probe the diffusive behaviour of a series of short-chain primary alcohols within a mesoporous catalyst support material; through the comparison of our results with highly surface-sensitive NMR relaxation data, we show that the evaluation of bulk-pore diffusion dynamics may provide a simple and indirect method to access and explore surface interaction phenomena occurring at the catalyst-liquid interface. [ABSTRACT FROM AUTHOR]

High-viscous neat neem oil (NO) with low-viscous wintergreen oil (WGO) may be used in diesel engines without any engine modification. Based on the previous experimental results, equal-volume blending of NO and WGO was prepared based on the optimum performance. The main aim of this experimental research is to improve the performance of NO–WGO blend using lower- and higher-order alcohol in terms of performance, emission and combustion parameters of the engine. All the experiments were conducted in a single-cylinder CI engine producing 5.2 kW power at a constant speed of 1500 rpm at variable loads. This research aims to compare the outcome of injection and blending of alcohol with NO and WGO blend at various load conditions. Alcohols, namely methanol, ethanol, hexanol and octanol, were identified and were injected in the inlet manifold along with intake air and also blended with the test fuels volumetrically. Based on the previous experimental results conducted with various injection rates of all the alcohols with NO50–WGO50, the optimum injection rate of each alcohol was identified on a mass basis based on the engine performance. Methanol, ethanol, hexanol and octanol blend and injection ratio was fixed at 30%, 30%, 20% and 10% on a mass basis. According to engine combustion, performance and emissions results, the injection of hexanol and octanol had the result of improving brake thermal efficiency, brake specific energy consumption and exhaust gas temperatures compared to other blends. The maximum pressure and heat release rate for all the hexanol and octanol alcohol injection blends were higher at higher loads. The HC, CO and smoke emissions were lower with Hex20 and Oct10 with NO50–WGO50 blends injection. The decrease in emissions is a result of homogeneous mixture formation within preinjected alcohols as well as air and lower volume of base fuel injected within the mixture. Finally, the NOx emissions increased with alcohol injection in comparison with blending with tested fuels. [ABSTRACT FROM AUTHOR]

Densities of pure 1-heptanol, 1-decanol, n-heptane, n-octane, n-nonane, n-decane, and their binary liquid mixtures were measured over the entire range of composition at (288.15, 293.15, 298.15, 303.15, 308.15, 313.15) K and at atmospheric pressure (0.1 MPa). The experimental data were used to determine several thermophysical properties including, the excess molar volume ( V m E ) and coefficient of thermal expansion (α ). These excess properties were used to analyze the inter–intra molecular interactions in the liquid mixtures. In addition, the densities of the considered mixtures were modelled using a combination of differential evolution algorithm and artificial neural networks. The proposed methodology determined good models that were able to efficiently predict the density with an average absolute relative error lower than 0.2 %. [ABSTRACT FROM AUTHOR]

The aerobic oxidation of monoalcohols and diols to acetals is an important academic and industrial challenge for the production of fine chemicals and intermediates. The existing methods usually rely on a two-step process in which alcohols are first oxidized to aldehydes over metal catalysts (Ru, Pt, Pd) and then acetalized using acids. Due to the instability of aldehydes, how to avoid over-oxidation to their respective carboxylic acids and esters is a long-standing challenge. For this reason, certain non-conjugated dialdehydes have never been successfully produced from diol oxidation. Hereby we report a Ru@metal-organic framework (MOF) tandem catalyst containing ultra-fine Ru nanoparticles (< 2 nm) for direct alcohol to acetal conversion of monoalcohol and diols with no formation of carboxylic acids. Mechanistic study reveals that the presence of Lewis acid sites in the MOF work in concert with Ru active sites to promptly convert aldehydes to acetals thereby effectively suppressing the formation of over-oxidation byproducts. [ABSTRACT FROM AUTHOR]

Water extracts from soils of the Barents Sea coast (the Khaipudyr Bay) were analyzed for the contents of organic carbon and total nitrogen by the method of high-temperature catalytic oxidation with non-dispersive IR registration; the contents of low-molecular-weight acids, carbohydrates, and alcohols were determined by gas chromatography and gas chromatography–mass-spectrometry. The mass fraction of inorganic carbon was measured potentiometrically, and the content of inorganic nitrogen (N– N– ) was determined by photometry. In marsh soils (Tidalic Fluvisols (Arenic or Loamic, Epiprotosalic)), = 0.1–0.8, = 0.01–0.05 g/kg, = + 0.01, and = 7–21. The content of individual components does not exceed 20 mg/kg, including carbohydrates (50–90%), acids (10–50%), and alcohols (<3%). In peat horizons of tundra soils (Cryic Histosols and Histic Cryosols), = 4–10, ~ 0.2 g/kg, and = 25–56. Litter and peat horizons accumulate both individual humus components and total dissolved organic carbon. The total weight of the identified substances is 200–300 mg/kg, 80–90% of them are carbohydrates, 10–20% are acids, and 0–9% are alcohols. The accumulation of and (N– takes place above the permafrost table. It is argued that the ratios of organic forms of carbon and nitrogen in soil water extracts and the content of low-molecular weight organic compounds in soils can be used as indicators of pedogenic processes in the Far North. [ABSTRACT FROM AUTHOR]

Biotrickling filtration is one of the techniques used to reduce odorants in the air. It is based on the aerobic degradation of pollutants by microorganisms located in the filter bed. The research presents the possibility of using the electronic nose prototype combined with artificial neural network for biofiltration process monitoring in terms of reduction in n-butanol concentration and odour intensity of treated air. The study was conducted using two-section biotrickling filter packed with a commercially available mixture of peat and perlite during 42 days with different n-butanol inlet concentrations, i.e., 100, 200, 400, and 800 ppm. During the tests, a concentration and odour intensity removal efficiency of around 90% and 20% was obtained, respectively. It has been shown that the highest values were obtained for an inlet n-butanol concentration of 200–400 ppm. [ABSTRACT FROM AUTHOR]

Abstract: A possibility of using a number of aromatic and heteroaromatic carboxylic acids and their halogen anhydrides as reactive matrix compounds for the analysis of alcohols of different structures by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry has been studied. It is shown that the acylation of alcohols with nicotinic and quinoline-6-carboxylic acid chlorides gives derivatives with high desorption/ionization efficiency under MALDI conditions, and that the free acids formed as a result of the hydrolysis of anhydrides act as matrix compounds. The proposed approach is tested on a number of aliphatic, alicyclic, and aromatic alcohols. [ABSTRACT FROM AUTHOR]

Abstract: A new method of the derivatization of alcohols for their analysis by matrix-assisted laser desorption/ionization (MALDI) and surface-assisted laser desorption/ionization (SALDI) is proposed. The approach is based on the silylation of the analytes with bromomethylchlorodimethylsilane in the presence of tertiary amines to yield fixed-charge containing derivatives. The proposed method was tested using aliphatic alcohols, terpenols, and sterols. MALDI and SALDI mass spectra of all derivatives contain intense ion peaks corresponding to their cationic parts. [ABSTRACT FROM AUTHOR]

The effect of the composition of the generator gas on the yield and composition of the products from its transformation in the presence of cobalt and iron catalysts was investigated. Data on the dependence of the obtained organic compounds on the composition of the prepared catalysts and synthesis conditions are presented. Experiments showed that generator gases obtained from aerobic gasification of plant biomass can be used to produce paraffins, olefins, and monatomic alcohols without conditioning i.e., without separating the stoichiometric syngas from them. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) were in-situ deposited onto the ordered mesoporous carbon (OMC) to function as a novel SPME coating. The specific area, pore volumes and average pore diameter for OMC and AuNP/OMC were calculated to be 411 and 281 m g, 0.93 and 0.69 cm g, 7.1 and 6.8 nm, respectively. The results indicate that the introduction of AuNPs greatly enhances the extraction of anilines, probably due to the strong interaction between gold and amino groups. The composite material was coated onto a fiber which then gave enrichment factors in the range from 1143 to 3420 for anilines, 45 to 845 for alcohols and 86 to 545 for phenols, indicating its extraction selectivity towards aniline. Following desorption, four anilines were quantified by gas chromatography with flame ionization detection. The method has low limits of detection (0.072-0.18 μg L) and a good precision (1.9-3.8%). It was successfully applied to the analysis of anilines in river and drinking samples. Recoveries range from 83.9% to 107.7% and 94.0 to 113.1%, respectively. [ABSTRACT FROM AUTHOR]

Neotropical Heliconius butterflies are members of various mimicry rings characterized by diverse colour patterns. In the present study we investigated whether a similar diversity is observed in the chemistry of volatile compounds present in male wing androconia. Recent research has shown that these androconia are used during courting of females. Three to five wild-caught male Heliconius individuals of 17 species and subspecies were analyzed by GC/MS. Most of the identified compounds originate from common fatty acids precursors, including aldehydes, alcohols, acetates or esters preferentially with a C and C chain, together with some alkanes. The compounds occurred in species-specific mixtures or signatures. For example, octadecanal is characteristic for H. melpomene, but variation in composition between the individuals was observed. Cluster analysis of compound occurrence in individual bouquets and analyses based on biosynthetic motifs such as functional group, chain length, or basic carbon-backbone modification were used to reveal structural patterns. Mimetic pairs contain different scent bouquets, but also some compounds in common, whereas sympatric species, both mimetic and non-mimetic, have more distinct compound compositions. The compounds identified here may play a role in mate choice thus helping maintain species integrity in a butterfly genus characterized by pervasive interspecific gene flow. [ABSTRACT FROM AUTHOR]

Sodium bromate with bmim[HSO] has been found to be an excellent oxidizing agent in aqueous medium. NaBrO:bmim[HSO] oxidized 1,2-diols, α-hydroxyketones, and alcohols to the corresponding carbonyl compounds in excellent yields. This method offers advantages such as low cost reagents, aqueous reaction conditions, moderate temperatures and short reaction times and hence environmentally benign reaction. Moreover, the ionic liquid bmim[HSO] could be recycled for at least three times without loss of significant activity. Graphical abstract: [ABSTRACT FROM AUTHOR]

A study regarding the electrodeposition of nickel oxide particles on the activated multi-walled carbon nanotubes from 2 M NaOH solution containing Ni(NO) and EDTA was carried out. The electrodeposition process was carried out using an optimized double-pulse sequence of potentials: E = −0.2 V vs. SCE ( t = 0.3 s) and E = 0.7 V vs. SCE ( t = 0.03 s). Spectroscopic XPS investigations and SEM analysis were used in order to characterize the surface and morphology of the studied modified electrode. Cyclic voltammetry and chronoamperometry were used in order to evaluate the electrochemical/amperometric performance of the GC/MWCNT-Ni electrode toward the oxidation of some aliphatic alcohols in strong alkaline medium. [ABSTRACT FROM AUTHOR]

Gold-based heterogeneous catalysts have attracted significant attention due to their selective partial oxidation capabilities, providing promising alternatives for the traditional industrial homogeneous catalysts. In the current study, the energetics of adsorption/desorption of alcohols (CHOH/methanol, CHCHOH/ethanol, CHCHCHOH/ n-propanol) and esters (HCOOCH/methyl formate, CHCOOCH/methyl acetate, and CHCOOCHCH/ethyl acetate) on a planar Au(111) surface was investigated in conjunction with oxidative coupling reactions by means of temperature programmed desorption (TPD) and dispersion-corrected density functional theory (DFT) calculations. The results reveal a complex interplay between inter-molecular and surface-molecule interactions, both mediated by weak van der Waals forces, which dictates their relative stability on the gold surface. Both experimental and theoretical adsorption/desorption energies of the investigated esters are lower than those of the alcohols from which they originate through oxidative coupling reactions. This result can be interpreted as an important indication in favor of the selectivity of Au surfaces in alcohol oxidative coupling/partial oxidation reactions, allowing facile removal of partial oxidation products immediately after their generation preventing their complete oxidation to higher oxygenates. [ABSTRACT FROM AUTHOR]

The apparent molar heat capacities, C , of ethanol, n-propanol, n-butanol, and tetraethylammonium, tetra- n-propylammonium, tetra- n-butylammonium and tetra- n-pentylammonium bromides have been measured measured using a Picker flow calorimeter (Sodev, Canada, Model CP-Cpr) at 298.15 K in water- N, N-dimethylformamide (DMF) mixtures. The contribution of the CH moiety, C (CH), was estimated from these data as the change in C per additional CH unit. The values of C (CH) in water (ca. 100 J·K·mol) are two to three times those in neat organic solvents (ca. 30-40 J·K·mol), consistent with a substantial contribution from hydrophobic solvation in water. In water-rich aqueous DMF solutions, C (CH) decreases monotonically with increasing DMF concentration, the decrease being more rapid for the n-alcohols. This trend differs significantly from that reported in the literature for highly aqueous mixtures of t-butanol, where C (CH) passes through a maximum. [ABSTRACT FROM AUTHOR]

In this work an effort has been made to show the effect of an alcohol-rich environment on imidazolium-based ionic liquids at 298.15 K using an isothermal titration calorimeter. It is divulged from this study that the thermal behavior expressed in terms of excess partial molar enthalpy, $$ H_{\text{IL}}^{\text{E}} $$ , of ionic liquids in various linear alcohols is governed by the increasing hydrophobicity of the residual alkyl group attached to the cation of an ionic liquid and to the alcohol molecules. An interesting observation about the systems consisting of ethylated residuals on both the cations of the ionic liquid and the alcohol molecules is that these systems do not follow the trend exhibited by other ionic liquid-alcohol systems. Interesting information on ionic interactions is obtained by using a simple methodology that gives the enthalpic interaction parameter $$ H_{{I{\text{L - IL}}}}^{\text{E}} $$ . [ABSTRACT FROM AUTHOR]

1,3-Oxathiolanes are rapidly cleaved by nickel boride allowing regeneration of corresponding carbonyl compounds. Optimum reaction conditions have also been defined to obtain alcohols exclusively by reduction of oxathiolanes. Reactions are rapid at room temperature and do not require protection from atmosphere. Mild reaction conditions, simple work up, and high yields are some of the major advantages of the procedure. Graphical abstract: [ABSTRACT FROM AUTHOR]

Transition metal-free oxidation of alcohols catalyzed by carbon quantum dots (CQDs) with NaClO oxidant using water as an only solvent was developed. High quality CQDs were synthesized via a simple one-pot electrochemistry method using cheap graphite rod as substrate materials, without the assistance of any chemicals but only pure water. The morphologies and composition of the resulting catalyst were characterized in detail. The results indicated that the CQDs catalyst showed higher activity and selectivity comparing to other carbon based transition metal-free catalyst (such as carbon nanotubes, graphene et al.) in the selective oxidation of alcohols to aldehydes. The high performance of the CQDs can be mainly attributed to its small particle size and large amounts of surface oxygen containing groups. The CQDs catalyst can be reused five times without any significant loss in their catalytic activities. Graphical Abstract: [ABSTRACT FROM AUTHOR]