Absorption Of Alcohols Research Articles

MoS2/Ni3S2/Reduced Graphene Oxide Nanostructure as an Electrocatalyst for Alcohol Fuel Cells

The development of active and stable catalysts is essential for the commercialization of direct alcohol fuel cells. In this work, we introduce a MoS2/Ni3S2/rGO catalyst as a cost-effective, stable, and high-performance catalyst for application in alcohol fuel cells. MoS2/Ni3S2 and its hybrid with reduced graphene oxide (rGO) are synthesized and evaluated as nanocatalysts in the alcohol (methanol and ethanol) electro-oxidation process in alkaline media. The effects of temperature and scanning rate are investigated. Voltammetry results show that MoS2/Ni3S2/rGO has good catalytic efficiency and excellent stability of 106 and 104% after 200 consecutive CV cycles for MOR and EOR, respectively. The synergic effect of starfish Ni3S2 and the coated porous MoS2 facilitates the absorption of hydroxyl ions and alcohols on the surface of the catalyst, while rGO enlarges the specific surface area and the electrical conductivity of the electrocatalyst.

Integrating the opposites of biofuel production: absorption of short-chain alcohols into oleaginous yeast cells for butanol recovery and wet-extraction of microbial oil

Absorption of butanol from water into oleaginous yeast cells with subsequent microbial oil separation by wet-extraction is a step towards hybrid biofuel production.

Solubility of Organics in Triethylene Glycol: Phase Equilibrium Modelling Using the Dortmund and LYNGBY Modified UNIFAC Models

 Abstract—This work is an attempt to predict the solubility of 60 volatile organic compounds (VOCs) in triethylene glycol aimed at thermodynamically testing the suitability of this solvent as an absorbent for the selected organics. The VOC main groups studied were alkanes, alkenes, alkynes, aldehydes, carboxylic acids and alcohols. The Modified UNIFAC Dortmund and Lyngby models were to study the required phase equilibrium as a function of temperature and composition. Triethylene glycol was found to be suitable for the absorption of low molecular weight aldehydes, alcohols and carboxylic acids. Generally, the infinite dilution activity coefficients computed in this study were low (below 100) indicating that the polymeric solvent studied in this work gave favourable phase equilibrium compared to water, the common industrial solvent. The solubility of VOCs was also found to decrease with increase in solute molecular weight. Compared with literature findings, the Dortmund performed better than the Lyngby procedure. However both models failed to accurately predict phase equilibrium behaviour. The authors therefore agree with literature findings that a specialised group interaction needs to be created for this solvent in the UNIFAC models in order to satisfactorily predict activity coefficients for the studied binary interactions.

Absorption of Hydrogen Bond Donors by Pyridyl Bis-Urea Crystals

A one-dimensional crystalline solid built from pillars of self-assembled bis-urea pyridyl macrocycles affords a close packed structure with no pores. These organic pillars contain unsatisfied urea oxygen lone pairs that can be used to drive the absorption of alcohols including trifluoroethanol, phenol, pentafluorophenol, and ethylene glycol to give well-ordered host:guest complexes with repeatable stoichiometry. The driving force for reversible solid transitions appears to be the formation of hydrogen bonds between the guest and an unsatisfied hydrogen bond acceptor, which is a lone pair of the urea oxygen. Halogen bonding with the electrophilic iodide in pentafluoroiodobenzene can also drive absorption by the host to give a well-ordered host:guest complex. These results suggest that the organic solid-state is surprisingly dynamic and may have potential applications for sorbents.

Metabolism of Silage Alcohols in Lactating Dairy Cows

Dairy cows fed silage are subjected to various alcohols and low molecular weight esters. Four lactating Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the hepatic portal vein, hepatic vein, mesenteric vein, and mesenteric artery were used to study the absorption of alcohols into portal blood and the metabolism of feed alcohols in the rumen and splanchnic tissues. The cows were allocated to 4 experimental treatments in a Latin square design. All treatments were formulated as total mixed rations with the same overall nutrient composition, differing by the source of corn silage. Treatments were a control silage and 3 qualities of problematic corn silage (silage with Fusarium toxin, Penicillium-infected silage, and silage with a high propanol content). Feeding was followed by a decreasing ruminal pH, as well as decreasing molar proportions of ruminal acetate and isobutyrate. The ruminal concentrations of total VFA, ethanol, propanol, 2-butanol, ethyl acetate, propyl acetate, glucose, and l-lactate, and molar proportions of propionate, butyrate, isovalerate, valerate, and caproate increased after feeding. Treatments affected ruminal concentrations of propanol, propyl acetate, and butyrate and a strong correlation was observed between ruminal propyl acetate and the molar proportion of butyrate (r=−0.79). Arterial concentrations of ethanol, propanol, propanal, acetone (sum of acetone and acetoacetate), 3-hydroxybutyrate, l-lactate, glutamate, and glutamine increased, and the arterial concentration of glucose decreased after feeding, but no effects of treatment were observed for arterial variables. The postprandial increase in arterial ethanol was maintained for 5h. The net portal release of ethanol tended to decrease with the treatment with the lowest ethanol content, and the net splanchnic release of ethanol increased after feeding, but overall, the net splanchnic flux of ethanol was not different from zero, in agreement with the liver being the major organ for alcohol metabolism. The net portal flux and net hepatic flux of propanol were affected by treatment. All dietary ethanol and propanol were accounted for by absorption of the respective alcohol into the portal blood. The hepatic extraction ratios of ethanol and propanol were, on average, 63 to 66%, and no indications of saturation of hepatic alcohol metabolism were observed at any time. We concluded that typical amounts of alcohols in corn silage do not interfere with splanchnic metabolism of any of the measured variables and do not saturate hepatic pathways for alcohol metabolism. However, even low concentrations of alcohols in feed might affect ruminal metabolism and are followed by hours of elevated peripheral blood concentrations of alcohols.

Can Alcohol-Based Hand-Rub Solutions Cause You To Lose Your Driver's License? Comparative Cutaneous Absorption of Various Alcohols

We assessed cutaneous ethanol (ETOH) and isopropanol (ISOP) absorption after intensive (30 times per h) use of alcohol-based hand-rub solutions by healthcare workers (HCWs). ETOH was detectable in the breath of 6/20 HCWs (0.001 to 0.0025%) at 1 to 2 min postexposure and in the serum of 2/20 HCWs at 5 to 7 min postexposure. Serum ISOP levels were unrecordable at all time points.

Wound-induced green leaf volatiles cause the release of acetylated derivatives and a terpenoid in maize

Green leaf volatiles (GLVs), generally occurring C 6 alcohols, aldehydes and acetates from plants, play an important role in plant–plant communication. These compounds induce intact plants to produce jasmonic acid, and induce defense-related gene expression and the release of volatile compounds. Here, we address wound-induced GLVs cause the release of acetylated derivatives and a terpenoid, ( E)-4,8-dimethylnona-1,3,7-triene (DMNT) in intact maize, which may be a type of plant–plant interaction mediated by airborne GLVs. Upon exposure of intact maize seedlings to wound-induced GLVs, ( Z)-3-hexenyl acetate was consistently the most abundant compound released. Exogenous application of individual alcohols and aldehydes mostly resulted in the release of corresponding acetate esters. C 6-alcohols with a double bond between the second and third, or the third and fourth carbon atoms, C 5- or C 6-aldehydes, and ( Z)-3-hexenyl acetate triggered the release of DMNT. When ( Z)-3-hexenyl acetate and hexyl acetate were used to treat maize seedlings, they were recovered from the plants. These data demonstrated that: (1) apart from direct adsorption and re-release of acetate esters, absorption and conversion of exogenous alcohols and aldehydes into acetate esters occurred, and (2) DMNT was induced by a range of aldehydes and unsaturated alcohols.

Process of adsorption–desorption for a series of chemically similar solvents trough ethylene vinyl acetate polymer. Modelling and experiment

The process of absorption and desorption of some alcohols through polymers materials are studied here in order to evaluate the capacity for absorption for these liquids, and to determine the effect of vinyl acetate incorporated in the polymer. The polymer exhibits low capacity and high diffusivity depending on two parameters: size of sorbed penetrant, and vinyl acetate percent. A mathematical model, based on a numerical method with finite differences, is built in order to describe the process. The model can lead to the kinetic of transfer of alcohols, in good agreement with experiments for either absorption or desorption of alcohols. The profiles of concentration as well as the kinetics are evaluated.

The Effects of Void Geometry and Contact Angle on the Absorption of Liquids into Porous Calcium Carbonate Structures

The absorption (permeation) of alcohols into porous blocks of calcium carbonate has been studied experimentally and with a computer model. The experimental measurement was of change in apparent weight of a block with time after contact with liquid. The modeling used the previously developed ‘Pore-Cor’ model, based on unit cells of 1000 cubic pores connected by cylindrical throats. To gain some insight into absorption into voids of complex geometry, and to provide a representation of heterogeneities in surface interaction energy, the cylindrical throats were converted to double cones. Relative to cylinders, such geometries caused hold-ups of the percolation of nonwetting fluids with respect to increasing applied pressure, and a change in the rate of absorption of wetting fluids. Both the measured absorption of the alcohols and the simulated absorption of the alcohols and of water showed significant deviations from that predicted by an effective hydraulic radius approximation. The simulation demonstrated the development of a highly heterogeneous wetting front, and of preferred wetting pathways that were perturbed by inertial retardation. The findings are useful in the design of high-performance, low-waste pigments for paper coatings, and environmentally friendly printing inks, as well as in wider industrial, environmental, and geological contexts.

Formation of Supramolecular Structures of Aroma Compounds with Polysaccharides of Corn Starch Cryotextures

The binding absorption of individual alcohols, ketones, alkyl acetates and their mixtures — used as aroma compounds — from aqueous solutions by corn starch cryotextures was studied by capillary gas chromatography at different starting concentrations of the odourants (1—25 mmol/L). The amount of compound sorbed by the cryotextures increases with concentration of this compound in the initial sol and increasing length of the alkyl chain in the corresponding compound. Linear equations describing the concentration dependence were proposed. The presence of octanol in the mixture increases the binding of hexanol as compared to hexanol alone. The methods of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, differential scanning microcalorimetry (DSC) and scanning tunneling microscopy (STM) were used for estimation of the microstructure of sols, and cryotextures, and for the determination of supramolecular complex formation in the systems odourant/cryotexture and odourant/sol. It was shown that waxy corn cryotextures do not form supramolecular complexes with aroma compounds.

Passive permeability of dihexadecyl phosphate vesicles altered by aliphatic alcohols and ω-diols

Alcohols act as anaesthetics only up to a certain chain length, beyond which their biological activity disappears. Although the molecular nature of general target sites remains unknown, presently available data support the hypothesis that this ‘cut-off” in anaesthetic activity could be due to a corresponding cut-off in the absorption of long-chain alcohols into lipid-bilayer portions of nerve membranes. To test this hypothesis, we developed a method based on leakage of Ru(bpy) 3 2+ ions across the membrane of dihexadecylphosphate (DHP) vesicles induced by aliphatic alcohols (C 1 to C 18) and some of their ω-diol. The permeant effects of aliphatic linear alcohols expressed as PD 50 values rise to a maximum for n-dodecanol (PD 50=2×10 −3 m 1 −1). Dodecanol was found to be the alcohol which presents the greatest anaesthetic potency among the series of linear aliphatic alcohols (cut-off anaesthetic effect). The results are discussed in terms of the structural physicochemical and geometrical characteristics of the permeating alchohols.

Intestinal absorption of bile alcohols.

The absorption of bile alcohols by rat small intestine was studied using in vivo and in vitro preparations. In bile duct cannulated rats, intraduodenal administered bile alcohols were certainly absorbed and excreted in the bile, although the absorption was not so efficient as for bile acids. The absorption during a 24 h period for free bile alcohol, bile alcohol 3-sulfate, and bile alcohol 3-glucuronide was 60%, 31%, and 30% of the dose, respectively, compared with 98% for taurocholate. In situ recirculation experiments demonstrated the linear relationship between perfusate concentration and intestinal absorption for unconjugated and 3-sulfated bile alcohols. Everted gut sacs of rat ileum actively transported a bile alcohol possessing a sulfuric acid ester group on the side chain. However, free bile alcohol, bile alcohol 3-sulfate, and bile alcohol 3-glucuronide were not transported. These results indicate that bile alcohols having no negative charge on the side chain are absorbed by passive diffusion and not by active transport.

Etude des facteurs conditionnant l'absorption percutanee des alcools incorpores dans des melanges eau-monooleate de sorbitanne polyoxyethylene-myristate d'isopropyle

Percutaneous absorption of ethanol, butanol and octanol is studied in vitro on skin of hairless rats. Alcohols are introduced in various vehicles prepared with water-isopropyl myristate-polyoxyethylene sorbitan monooleate (Tween 80). In aqueous or isopropyl myristate solution, the permeability constant of alcohols increases in the same way as their partition coefficient, stratum corneum/vehicle. The addition of Tween 80 to the aqueous or isopropyl myristate solutions reduces the permeability constant of alcohols when they are initially poorly soluble in the pure solvent. The intensity of the effect is proportional to the quantity of surface-active agent added to the solvent and decreases with the stratum corneum/vehicle partition coefficient. In ternary systems with an external aqueous phase, results are similar to those obtained with water-Tween 80 solution. So percutaneous absorption of alcohols in a two phase mixture seems to be a function of the affinity of alcohols for the aqueous phase which are in contact with the stratum corneum. Absorption of alcohols is not modified by the viscosity of the various vehicles studied.

Vaginal Drug Absorption in Rhesus Monkeys I: Development of Methodology

Earlier reports from these laboratories described a procedure for determining vaginal drug absorption in the rabbit based upon a perfusion system, and data on the vaginal absorption of the straight-chain aliphatic alcohols and carboxylic acids were given. These studies have been extended to the rhesus monkey. Rib-cage-type cells were designed for intravaginal insertion through the vulval orifice and to fit the specific dimensions of the monkey vagina. The general design of the cell was similar to that used in the rabbit vaginal absorption studies. The persusion system was checked by using 3H-polyethylene glycol 4000, and no significant leaks from the cell were found. The absorption of the alcohols followed first-order kinetics. The computed apparent permeability coefficients for the alcohols were of comparable magnitude to those previously reported for the rabbit vaginal membrane.

Systems Approach to Vaginal Delivery of Drugs II: In Situ Vaginal Absorption of Unbranched Aliphatic Alcohols

The absorption of unbranched aliphatic alcohols in the rabbit vagina was studied using a perfusion method, and the absorption rates were found to be first order with respect to the drug concentration in the vagina from methanol to octanol. A physical model involving an aqueous diffusion layer in series with a membrane consisting of aqueous pores and lipoidal pathways was used for analyzing the data. The physically based parameters in the model were determined. An effective diffusion layer thickness (“unstirred layer”) of around 0.035cm was found. The increase in the permeability coefficient for the lipoidal pathway per methylene group was around 2.5 for this homologous series.

Interface and Adhesion Studies of Evaporated Se on Oxide Surfaces

Adhesion of evaporated amorphous Se on oxide surfaces has been studied. For selenium evaporated in a relatively poor vacuum of 10−5 Torr onto aluminum substrates coated with a surface oxide layer, the Se deposit could easily be peeled off the substrate. Electron microscope examination of the separated surfaces showed that the separation, in general, occurred at or in the immediate vicinity of the Se-aluminum oxide interface. Complimentary studies were also conducted on Se evaporated onto oxide substrates in an ultra-high vacuum system. Substrates used were single crystals of sapphire and MgO and virteous quartz. Experimental observations indicated that the relative strength of adhesion and the fractured surface features were dependent on and could be correlated with the substrate preheat temperaure in a high vacuum prior to Se evaporation. With a sufficiently high preheat temperature, the interfacial bond strength exceeded that of the cohesive energy of Se and the failure occurred in the Se layer. Studies on the effect of chemisorbed gas species on adhesion showed that water absorption does not degrade the strength of the Se-oxide structure. However, absorption of long chain organic acids and alcohols on the substrate surface resutled in poor adhesion strength, and the failure occurred at the interface region.

305. Hydroxy-steroids. Part I. Doublets in the hydroxyl absorption of monohydric alcohols

The first page of this article is displayed as the abstract.

Absorption of alcohols in gas-liquid chromatography applied to the determination of non-alcoholic impurities

Absorption of alcohols in gas-liquid chromatography applied to the determination of non-alcoholic impurities

The Near Infra-Red Absorption of Normal Alcohols and their Bromides

The Near Infra-Red Absorption of Normal Alcohols and their Bromides

Influence of Some Paramagnetic Ions on the Magnetic Resonance Absorption of Alcohols

Influence of Some Paramagnetic Ions on the Magnetic Resonance Absorption of Alcohols