Ethanol-water Mixtures Research Articles

Extraction of mycotoxin alternariol from red wine and from tomato juice with beta-cyclodextrin bead polymer

Alternariol (AOH) is a mycotoxin which occurs in wine and tomato products as contaminant. Cyclodextrins (CDs) are ring-shaped glucose oligomers. CD polymers seem to be suitable for the removal of certain mycotoxins from aqueous solutions, including different beverages. In our recent study, insoluble β-CD bead polymer (BBP) almost completely removed AOH from aqueous solutions (pH 3.0–7.4). In this study, the time- and temperature-dependence of AOH-BBP interaction as well as the regenerability of the polymer after mycotoxin binding were examined. Furthermore, we tested the ability of BBP to extract AOH from spiked wine and tomato juice samples, during which the quality of beverages was also monitored. In addition, we describe here a novel albumin-based method for the extraction of AOH from tomato juice, used to analyze the rest of the mycotoxin in these samples. AOH-BBP interaction did not show temperature dependence (20–40 °C), while the incubation time markedly affected the mycotoxin extraction. After AOH binding, we successfully regenerated BBP with 50 v/v% ethanol-water mixture. Moreover, BBP strongly decreased the AOH content of both wine and tomato juice samples, suggesting the potential suitability of CD polymers as AOH binders in some beverages.

Photoproduction of hydrogen in microreactors: Catalytic coating or slurry configuration?

A quartz microreactor containing 28 microchannels of 500 μm width and 105 mm length has been used to photoproduce hydrogen from liquid water-ethanol using an Au/TiO2 photocatalyst and UV light. The photomicroreactor has been tested in two flow configurations: (i) as a catalytic wall photoreactor by coating the microchannels with the photocatalyst, and (ii) as a slurry photoreactor by dispersing the photocatalyst in the liquid mixture of water-ethanol. The catalytic wall photoreactor configuration shows superior performance, with hydrogen yields more than three times higher than those obtained with the best slurry configuration under the same operation conditions.

Thermomechanical analysis and pH-triggered elastic response of charge-balanced sulfonated poly(tertiary amine-methacrylate)-based terpolymer cryogels

pH-responsive terpolymer poly(hydroxyethyl methacrylate-2-acrylamido-2-methyl-propanosulfonic acid-diethylaminoethyl methacrylate) cryogels and hydrogels (named as CGs-PHA/Dm and HGs-PHA/Dm) were synthesized in ethanol-water mixture using different monomer feed compositions. By the combination of three monomers, an interesting system was designed with tunable pH/temperature responsiveness and elasticity. ATR-FTIR spectrums obtained after swelling swelling in pH buffer solution of 2.1 indicated –R2NH+ stretching of DEAEMA moities in terpolymer matrices. By incorporation of DEAEMA units with ionizable amino groups, terpolymer CGs-PHA/Dm and HGs-PHA/Dm gels exhibited pH-responsive swelling behavior. Inclusion of DEAEMA dramatically altered pH-responsiveness of terpolymers in simulated intestinal fluid at pH 6.6. Dependence of interaction parameter χon terpolymer volume fraction in gel ν2by a linear function and its enthalpic/entropic components with swelling pH were determined. At pH < 6.6, dependence of χ parameter on the swelling was evaluated as χ=1.097-2.965ν2, while at basic pH region, pH > 6.6, χ=0.576+0.459ν2. Both pH of swelling medium and the amount of DEAEMA in terpolymer composition affected the compression moduli of terpolymer gels. Flory-Rehner theory extended to correlate the compressive modulus with swelling pH and the dependence of the effective crosslink density νeon mol% DEAEMA was expressed in both acidic and basic conditions. pH-triggered swelling/shrinking of terpolymer gels were studied as reversible cycles in buffer solutions of pH 2.1 and 9.8. DEAEMA-rich terpolymer gels showed overshooting phenomena due to dynamic conformational changes of diethylaminoethyl units. Terpolymer cryogels exhibited much faster swelling kinetics than that of terpolymer hydrogels in simulated gastric fluid at pH 2.1. The values of diffusion coefficient seemed to be strongly dependent of terpolymer composition.

New Fitting Method for Vapour-Liquid Equilibrium Data and its Application for Ethanol-Water Distillation Process Modeling

For modeling and simulation of distillation processes, the main information required is the vapour-liquid equilibrium (VLE) data. These are available as discrete values, but for modeling purpose, an analytical function would be more suitable. We developed a simple calculation protocol to obtain a single continuous function for the VLE curve on the entire concentration domain, without using thermodynamic functions. The fitting parameters of binary ethanol-water mixture VLE curve were determined. The methodology is suitable for fitting continuous functions on VLE data of any binary or multicomponent, non-ideal (even azeotropic) mixtures.

Antioxidant activity and content of salidroside in ethanolic extracts of Rhodiola rosea

Rhodiola rosea L. is an important medicinal plant, grown in the Arctic regions. Recently, many investigations are devoted to the development of new methods of extraction bioactive components from R.rosea. One of the valuable and common methods of extraction is maceration in the water-ethanol mixture to obtain tincture. At the same time, a certain drawback of systematic studies of the dependence of such extraction efficiency on the concentration of ethanol is noticeable in the literature. In this work data of systematical study of maceration efficiency of water-ethanol mixtures with ethanol content 0 – 97 vol.% at 25°C. Salidroside content and total antioxidant activity were estimated. It was obtained that the most useful for salidroside as well as other antioxidants extraction is maceration with 50 % water-ethanol mixture rot 3 days. These data can be used to organize the extraction process and for further studies in the field of optimization of the processes of extraction of bioactive compounds from R.rosea.

Characterization of MgO thin film prepared by spray pyrolysis technique using perfume atomizer

Transparent conducting magnesium oxide (MgO) thin films are obtained by pyrolytic decomposition of magnesium acetate in a mixture of ethanol and distilled water on to a glass substrate using perfume atomizer. The substrate temperature (Ts) is maintained at 300 °C, 350 °C, 400 °C, and 450 °C for depositing the films and annealed at 450 °C for 4 h. Then the samples were characterized by X-ray diffraction, field emission scanning electron microscope, atomic force microscope, UV–Vis spectroscopy, photoluminescence analyzer, and Raman spectrophotometer for identifying its structure, morphology, topography, bandgap and defect states. The XRD result demonstrates the cubic, polycrystalline nature with (2 0 0) preferred orientation. The presence of MgO2 phase along (2 2 2) plane increases with substrate temperature is noticed. From the SEM monograph, the clusters of spherical grains are observed for all the films and the columnar growth of the MgO film is observed from the AFM topographical image. The surface roughness tends to increase with substrate temperature. The MgO thin films possess two absorption bands and two optical bandgaps. The transmittance of 70% is obtained for MgO film which could be used for optoelectronic device and protective coating applications. The blue and green emission bands are identified from the PL spectrum. The defects in the film are responsible for linear I–V characteristic and the large forward current value implies higher efficiency for solar cell applications.

The Many Facets of Nanotechnology [Highlights

I first heard the word nanotechnology probably in the late 1980s, when the field was largely unknown and just beginning to sprout. Working with electrochemists in the early 1990s, I stumbled on a process for creating interesting patterns of nanoscale undulations on the surface of a commercially sourced aluminum foil using electropolishing. When the foil is electropolished in a suitable mixture of perchloric acid, butyl cellusolve, ethanol, and distilled water at certain voltages and for certain durations, these patterns spontaneously appear on the surface [1]. Examples are shown in Figure 1. Some of these patterns, like the ones that are formed after electropolishing at 50 V for 10 s, or 60 V for 30 s, are interesting in that they are well-ordered arrays of stripes and mounds. The explanation for their formation is not simple and involves the nonlinear dynamics of chemical processes that were first explained by my colleagues Prof. Albert Miller and Prof. Hseuh-Chia Chang from the University of Notre Dame [2], [3]. These patterns were interesting in their own right but did not immediately lead to anything very useful. However, something else did.

Simultaneous Prediction of the Density and Viscosity of the Ternary System Water-Ethanol-Ethylene Glycol Using Support Vector Machine

Ethylene glycol is an organic solvent used in extractive distillation to separate water-ethanol mixtures. An appropriate process description requires accurate physical property data. In this paper, experimental liquid densities and dynamic viscosities of pure ethylene glycol as well as the ternary system water-ethanol-ethylene glycol are presented over a wide temperature range (298.15 to 328.15 K) at atmospheric pressure. Density and viscosity data of the ternary system of water-ethanol-ethylene glycol solutions were obtained from the literature and a support vector machine model was used to predict the density and viscosity of this system. The determination coefficients for density and viscosity of the ternary system of water-ethanol-ethylene glycol are 0.9854 and 0.9892, respectively. The mean square errors of density and viscosity are obtained 4.6572×10-4 and 3.4920×10-4, respectively. The results confirmed that the proposed method can predict the density and viscosity of the ternary system of water-ethanol-ethylene glycol as a function of temperature, using a support vector machine.

Water repellency of soils on unpaved roads in coniferous forests

Forest roads play a crucial role in commercial forestry. Most of them are unpaved and exposed to increased surface runoff and the occurrence of soil erosion. Therefore, these roads constantly require repairs and maintenance, which are associated with the high cost of earthworks. Soil water repellency causes retardation of water infiltration into soil, which affects the generation of surface runoff, leading to the destruction of the active road layer. This phenomenon is well recognized in forest habitat soils, but poorly investigated in terms of soils constituting roads and communication routes. Therefore, the aims of this research were to determine the severity and persistence of potential water repellency in the case of soil collected from two unpaved roads in coniferous forest and to investigate the dependence between the severity of soil water repellency and its persistence. Soil samples (Dystric Brunic Arenosols) were collected from three points of the roadway, i.e., centre line, rut and roadside, from two different sites located in fresh coniferous and fresh mixed coniferous forest (Poland). The severity of soil water repellency was assessed, based on measured values of the wetting contact angle (Wilhelmy plate method) and the critical and 90° surface tensions. For this purpose, contact angle measurements of the solid phase, wetted by water–ethanol mixtures, were used and data results were analysed using the Zisman approach. The persistence of potential soil water repellency was assessed using the water drop penetration time test. The severity and persistence of soil water repellency depend on the forest habitat type surrounding the road and point locations on the road cross section. The soil samples collected from the roadside were more water repellent than samples taken from the centre line or rut. A strong relationship was found between the water drop penetration time and the advancing contact angle, the critical surface tension and the 90° surface tension.

Condensate droplet growth characteristics of Marangoni condensation of ethanol–water mixtures on a horizontal surface

In this study, an experimental system was designed and built to study the Marangoni condensation of ethanol–water mixtures on a horizontal surface, and the growth of condensate droplets during the time-series process was studied. The maximum radius and coverage ratio of droplets were introduced to analyse this process quantificationally. Droplet growth could be divided into two periods during the time-series process: the rapid increase period at the start due to the direct condensation and the fluctuation period in the subsequent process due to the coalescence and movement of the droplets. In the rapid increase period, the maximum radius of droplets obviously increased with the increase in the vapour-to-surface temperature difference, slightly increased with the increase in the vapour velocity and pressure and decreased with the increase in the ethanol vapour concentration. Conversely, in the fluctuation period, these effects were weakened owing to the coalescence and movement of the droplets. The droplet coverage ratio during the time-series process was complicated and dependant on several factors, especially condensation style. The fast movement of the condensate droplets may lead to the decrease in the droplet coverage ratio owning to the shorter residence time. An empirical formula for the droplet coverage ratio during the time-series process was proposed on the basis of the experimental results, and the deviation ranged from -19.5% to 30.0% for 95% of the data.

Structure, Antimicrobial Activity, Hirshfeld Analysis, and Docking Studies of Three Silver(I) Complexes-Based Pyridine Ligands

Three broad spectrum Ag(I) complexes against MDR (multi drug resistance) and ATCC standard bacteria as well as the fungus C. albicans were presented. The three well-known structurally-related Ag(I) complexes, [Ag(pyridine-3-carboxaldhyde)2NO3], 1, [Ag3(2-pyridone)3(NO3)3]n, 2, and [Ag(3-hydroxypyridine)2]NO3, 3, were prepared by the direct combination of AgNO3 with the corresponding pyridine ligands in a water-ethanol mixture. 1 and 3 are molecular compounds while, 2 is a 2D coordination polymer with sheets bridged by strong homoleptic R2,2(8) hydrogen bonds between ligands giving the ins topology. Different contacts affecting the molecular packing in their crystal structures were computed by employing Hirshfeld analysis. Charge transferences from the ligand groups to Ag(I) were analyzed using natural population analysis. The effect of protonation and metal coordination on the tautomerism of 2-pyridone was analyzed using data from the Cambridge Structure Database (CSD). It was found that Lewis acid attachment to both N and O sites favor a state in between the two formal tautomers. All compounds were significantly more active than 17 tested commercial antibiotics against three clinically isolated strains of Ps. Aeruginosa, with 2 and 3 performing best on average against all ten tested bacterial strains but with 3 containing less Ag per weight. Finally, docking studies were carried out to unravel the inhibition mechanism of the synthesized silver(I) complexes.

Energy conditions assessment of a two-phase annular thermosyphon used as heat supplier for a new pilot-scale falling film distillation unit

Energy-efficient chemical processes save resources and provide sustainability. Conventional distillation is notably known as an energy-intensive process, which motivated our research group to develop a new thermosyphon-assisted falling film distillation apparatus (Destubcal technology), where heat is supplied through the condenser of an annular thermosyphon coupled to the distillation tube. From this new design, two possible configurations of energy supply were studied: isothermal and temperature-profile conditions in the condenser of the annular thermosyphon. The distillation tube was fed with ethanol-water mixture, varying the feed flow rate and feed temperature, as well as the power of electrical resistances in the evaporator of the annular thermosyphon. Temperature-profile condition leads to a better heat transfer distribution, resulting in higher temperatures in the distillation tube and so higher ethanol recovery in the distilled product. In this way, temperature-profile operation proved to be more advantageous for this new thermosyphon-assisted distillation unit, corroborated by the separation factor, reaching a 10.3% increase. The analysis of operational variables showed that smaller potencies in the evaporator allow better separation, an important aspect of energy intensification. Thereby, this works contributes towards the urgent demand for novel thermal intensified proposals, indicating the best operational conditions for an advanced falling film distillation unit.

Ice formation and growth in supercooled water–alcohol mixtures: Theory and experiments with dual fiber sensors

Increased knowledge on fluid-solid phase transitions is needed, both when they are undesired and can impair process operations, and when strict control is required in fields such as food technology, the pharmaceutical industry and cryogenic CO2 capture. We present experimental results and theoretical predictions for the solid-formation and melting temperatures of ice in four binary water–alcohol mixtures containing methanol, ethanol, 1-propanol and 1-butanol. A dual fiber sensor set-up with a fiber Bragg grating sensor and a thin-core interferometer is used to detect the solid-formation. The predictions of melting temperatures with the cubic plus association equation of state combined with an ice model are in good agreement with experiments, but deviations are observed at higher alcohol concentrations. The measured degree of supercooling displays a highly non-linear dependence on the alcohol concentration. A heterogeneous nucleation model is developed to predict the solid-formation temperatures of the binary alcohol–water mixtures. The predictions from this model are in reasonable agreement with the measurements, but follow a qualitatively different trend that results in systematic deviations. In particular, the predicted degree of supercooling is found to be an essentially colligative property that increases smoothly with alcohol concentration. Experimental results are also presented for the growth rate of ice crystals in water–ethanol mixtures. For pure water, the measured crystal growth rate is 10.2 cm/s at 16 K supercooling. This is in excellent agreement with previous results from the literature. The crystal growth rate observed in ethanol–water mixtures however, can be orders of magnitude lower, where a mixture with 2% mole fraction ethanol has a growth rate of 2 mm/s. Further work is required to explain the large reduction in crystal growth rate with increasing alcohol concentration and to reproduce the behavior of the solid-formation temperatures with heterogeneous nucleation theory.

Unraveling How Ethanol-Induced Conformational Changes Affect BSA Protein Adsorption onto Silica Surfaces.

Protein adsorption at solid-liquid interfaces is highly relevant to a wide range of applications such as biosensors, drug delivery, and pharmaceuticals. Understanding how protein conformation in bulk solution impacts adsorption behavior is fundamentally important and could also lead to the development of improved protein-based coatings. To date, relevant studies have been conducted in aqueous solutions, while it remains largely unknown how organic solvents and more specifically solvent-induced conformational changes might influence protein adsorption. Herein, using the quartz crystal microbalance-dissipation (QCM-D) and localized surface plasmon resonance (LSPR) techniques, we systematically investigated the real-time adsorption behavior of bovine serum albumin (BSA) protein onto silica surfaces in different water-ethanol mixtures ranging from 0 to 60% (v/v) ethanol. The results showed that there was greater protein adsorption at higher ethanol fractions in the 10-30% range, while more complex adsorption profiles were observed in the 40-60% range. The combination of QCM-D and LSPR measurements led us to further identify specific cases in water-ethanol mixtures where washing steps caused densification of the adsorbed protein layer as opposed to typical desorption of weakly adsorbed molecules in aqueous conditions. We discuss mechanistic factors that drive these overall adsorption trends by taking into account how ethanol fraction affects BSA conformation in bulk solution. Together, our findings demonstrate that BSA proteins can adsorb onto silica surfaces across a wide range of water-ethanol mixture conditions, while specific adsorption profiles depended on the ethanol fraction in a manner closely linked to solution-phase conformational properties.

Intensified synthesis for ethyl lactate production including economic, sustainability and inherent safety criteria

A methodology for gradual process intensification is applied to a conventional flowsheet for the production of the green solvent ethyl lactate from ethyl alcohol and lactic acid. The approach takes the base design and integrates two pieces of equipment into one at each step of the intensification task. The concepts of phenomena building blocks and simultaneous phenomena building blocks are used to track the intensification steps, and each intensified structure is rated through economic, environmental, sustainability and inherent safety metrics. The process involves the separation of an ethanol-water azeotropic mixture, for which an extractive distillation system is used. Two entrainers were considered for the extractive distillation process, one based on a mixture of ethylene glycol/glycerol, and the other one on acetol. The results of intensifying an original flowsheet with a reaction unit and 4 separating units into two pieces of equipment showed that significant economic savings and improvements in the sustainability and inherent metrics can be obtained.

Selective Permeation of Water through Angstrom-Channel Graphene Membranes for Bioethanol Concentration.

Graphene-based laminate membranes have been theoretically predicted to selectively transport ethanol from ethanol-water solution while blocking water. Here, robust angstrom-channel graphene membranes (ACGMs) fabricated by intercalating carbon sheets derived from chitosan into thermally reduced graphene oxide (GO) sheets are reported. ACGMs with robust and continuous slit-shaped pores (an average pore size of 3.9 Å) are investigated for the dehydration of ethanol. Surprisingly, only water permeates through ACGMs in the presence of aqueous ethanol solution. For the water-ethanol mixture containing 90wt% ethanol, water can selectively permeate through ACGMs with a water flux of 63.8±3.2kg m-2 h-1 at 20°C and 389.1±19.4kg m-2 h-1 at 60°C, which are over two orders of magnitude higher than those of conventional pervaporation membranes. This means that ACGMs can effectively operate at room temperature. Moreover, the ethanol can be fast concentrated to high purity (up to 99.9wt%). Therefore, ACGMs are very promising for production of bioethanol with high efficiency, thus improving its process sustainability.

Rotation of small diatomics in water-ethanol mixture: Multiple breakdowns of hydrodynamic predictions.

We study the rotational and translational dynamics of three small important linear molecules, namely, carbon monoxide (CO), nitric oxide (NO), and cyanide ion (CN-) in water-ethanol mixtures, at different compositions. Here, we report a detailed study of the dynamics of these diatomics in water-ethanol binary mixtures for the first time. We find multiple anomalous results, namely, (i) faster rotational motion of CO and NO than CN-, (ii) larger translational diffusion of CO and NO in pure ethanol than in water but the reverse for CN-, (iii) a pronounced anomaly in the composition dependence of translational-rotational dynamics at low ethanol composition, and (iv) a re-entrant type behavior in the viscosity dependence of orientational relaxation. We compare our simulation result-based observations with the existing experimental results wherever available and find that the simulation results are in reasonably good agreement with the experiments. We implement, for the first time, a calculation of the rotational binary friction following the sophisticated scheme of Evans and co-workers. We also calculate the hydrodynamic predictions for the solute molecules. On comparison with the simulation and experimental results, we find that neither the rotational binary friction nor the hydrodynamic expressions (both stick and slip) can reproduce the results. To rectify the situation, we develop a detailed mode-coupling theory and suggest that such an approach if completely implemented can provide a more reliable description than the hydrodynamic approach. Many of our results could be tested in experimental studies because these linear molecules are amenable to spectroscopic studies, such as 2D-IR.

In Vitro Anti-Helicobacter Pylori and Antimycobacterial Activity Evaluation Of Selected Plants From Turkey

In this study, the extracts of Ulmus minor Mill. subsp. minor (Ulmaceae), Lathyrus pratensis L. (Leguminosae), Glaucium leiocarpum Bois. (Papaveraceae), and Echium vulgare L. (Boraginacea) were investigated for their in vitro anti-Helicobacter pylori and anti-mycobacterial activity. &#x0D; The air-dried plant material was powdered and extracted with 70% ethanol by maceration. The extract was filtered and evaporated to dryness under the vacuum and then dissolved in a water-ethanol (90:10) mixture and extracted with dichloromethane and ethyl acetate, respectively. Antibacterial activity was investigated by microdilution method against Helicobacter pylori ATCC 43504, Mycobacterium smegmatis ATCC 14468 and Mycobacterium avium ATCC 25291.&#x0D; The ethyl acetate extract of U. minor showed activity with MIC of 250 µg / mL against H. pylori. The other extracts showed no or weak inhibitory activity at &gt;2000 µg/mL concentrations against the tested microorganisms. In conclusion, ethyl acetate extract of U. minor may be used for the treatment of H. pylori infections.

A miniaturized SIW circular cavity resonator for microfluidic sensing applications

This letter presents a miniaturized microfluidic sensor based on substrate integrated waveguide (SIW) cavity resonator. By choosing a circular cavity, a strong electric field is established in the center of the cavity, and the fluidic channel with sample under test is set up in the middle of the cavity for highly sensitive sensing. Several meander slots are loaded on the top of the cavity, which can extend the current flowing path and reduce the resonant frequency, thus the proposed structure is greatly miniaturized compared to the traditional resonators. The corresponding circuit model of the proposed sensor is derived and analyzed. Furthermore, the proposed sensor has been fabricated and tested. The water-ethanol mixture is used for verification. The measured results agree well with the simulated ones, and show that the sensor can distinguish different samples accurately. The resonant sensor works around 2.6 GHz, and shows very good sensitivity for permittivity change with miniaturized structure (0.31 × 0.29 × 0.0069 λ03). The sensor presents high sensitivity and excellent stability in a small size, which provide a novel solution to portable monitoring device.

Fractionating and Purifying Softwood Kraft Lignin with Aqueous Renewable Solvents: Liquid-Liquid Equilibrium for the Lignin-Ethanol-Water System.

Hot ethanol-water solutions can be used to simultaneously fractionate and purify softwood Kraft lignin through the Aqueous Lignin Purification with Hot Agents (ALPHA) process, using the regions of liquid-liquid equilibrium (LLE) that form at selected temperatures and solvent-to-lignin feed (S/F) ratios. Lignin, ethanol, and water compositions are measured for the solvent-rich (SR) and lignin-rich (LR) liquid phases in mutual equilibrium, as well as the lignin and metals mass distributions between the two phases. As depicted in quasi-ternary diagrams for clarity, both temperature and S/F ratio can be used to grow, merge, and even split the regions of LLE, giving significant control over both molecular weight (MW) and lignin purity. For example, a solvent comprising 45:55 EtOH/H2 O at 75 °C and an S/F ratio of 6:1 enables recovery of an ultrapure (95 % of Na removed), higher MW (Mn =8400 Da) lignin fraction in the LR phase. On the other hand, 95:5 EtOH/H2 O at 45 °C and S/F=3:1 enables recovery of an ultrapure, low MW (1500 Da) lignin in the SR phase.