Aqueous Ethanol Solution Research Articles

Zwitterionic polyamide membranes via in-situ interfacial polymerization modification for efficient pervaporation dehydration

Thin-film composite membranes (TFC) comprised of polyamide have emerged as a promising candidate in molecular separations due to their ultrathin selective layer and controllable structure. However, improving selectivity while retaining satisfactory permeability of TFC membranes remains a great challenge. Herein, zwitterionic polyamide membranes have been fabricated for pervaporation dehydration via in-situ interfacial polymerization modification (in-situ IPM) strategy. In-situ amination of the substrates can improve the interface compatibility between the selectivity layer and the substrate through fourier transform infrared spectroscopy (FTIR) characterization, making the membranes more stable to resist the structural evolution in liquid conditions. The zwitterion modification afterwards endows the membranes with dense structure and improved hydrophilicity through X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and contact angle measurements. The optimized zwitterionic polyamide membrane with well-defined structure realizes superior separation performance with a separation factor of 3870 while maintaining a high permeation flux of 4380 g m−2 h−1 when processing 90 wt% ethanol aqueous solution at 76 °C, outperforming most reported TFC membranes. Moreover, the zwitterionic polyamide membrane also exhibits stable separation performance under the successive test. This work would provide a feasible scheme for the design of efficient TFC membranes for pervaporation dehydration.

Influence of Pt Oxidation State on the Activity and Selectivity of g-C3N4-Based Photocatalysts in H2 Evolution Reaction

Graphitic carbon nitride g-C3N4 has been modified using platinum and platinum oxide (0.5–5 wt.%) and studied in photocatalytic H2 evolution reactions with ethanol aqueous solution under visible light irradiation (λ = 409 nm). An analysis of the by-products of the reaction (CO2, CH4, C2H6 etc.) was also carried out. The morphology, particle size distribution, and optical properties of the photocatalysts, and the chemical states of platinum cations were examined using various methods. The photocatalysts were investigated using a wide range of methods to clarify the morphology, particle size distribution, optical properties, and the chemical states of platinum cations. Factors affecting not only the activity, but also the selectivity of the photocatalyst in the target process of hydrogen production, have been established. The highest rate of H2 evolution achieved over 0.5 wt.% Pt/g-C3N4 photocatalyst is 0.6 mmol h−1 g−1 (selectivity 98.9%), which exceeds the activity of pristine g-C3N4 by 250 times. Increasing the Pt or PtO content up to 5 wt.% leads to an increase in the rate of formation of by-products (CH4, C2H6, and CO2) and a decrease in the selectivity of H2 evolution. The study also delves into the role of platinum and the mechanism of charge transfer in PtO/g-C3N4 and Pt/g-C3N4 photocatalysts due to light irradiation.

A single 8-hydroxyquinoline-appended bile acid fluorescent probe obtained by click chemistry for solvent-dependent and distinguishable sensing of zinc(II) and cadmium(II).

Construction of fluorescent probes for zinc ion (Zn2+ ) and cadmium ion (Cd2+ ) is significant for the safety of humans. However, the discriminating recognition of Zn2+ and Cd2+ by a single probe remains challenging owing to their similar properties. Herein, a novel deoxycholic acid derivative containing 8-hydroxyquinoline fluorophore has been facilely synthesized through click chemistry to form a clamp-like probe. Using its perfect bonding cavity from 1,2,3-triazole and quinoline, this molecule showed favorable solvent-dependent fluorescent responses and distinguished Zn2+ and Cd2+ in different solvents. In ethanol aqueous solution, it displayed good selectivity and ratiometric fluorescence to Zn2+ with 30 nm spectroscopic red-shifts. In acetonitrile aqueous solution, it exhibited good selectivity and ratiometric fluorescence to Cd2+ with 18 nm spectroscopic red-shifts. Moreover, the unique microstructural features of the probe in assembly were used to reflect its recognition processes. Due to its merits of low detection limit and instant response time, the probe was utilized for sensing Zn2+ and Cd2+ in water, beer and urine with high accuracy. Meanwhile, this probe served as a handy tool and was employed to obtain inexpensive test strips for the prompt and semiqualitative analysis of Zn2+ and Cd2+ with the naked eye.

The Role of the Gravitational Field in Generating Electric Potentials in a Double-Membrane System for Concentration Polarization Conditions.

Electric potentials referred to as the gravielectric effect (∆ΨS) are generated in a double-membrane system containing identical polymer membranes set in horizontal planes and separating non-homogenous electrolyte solutions. The gravielectric effect depends on the concentration and composition of the solutions and is formed due to the gravitational field breaking the symmetry of membrane complexes/concentration boundary layers formed under concentration polarization conditions. As a part of the Kedem-Katchalsky formalism, a model of ion transport was developed, containing the transport parameters of membranes and solutions and taking into account hydrodynamic (convective) instabilities. The transition from non-convective to convective or vice versa can be controlled by a dimensionless concentration polarization factor or concentration Rayleigh number. Using the original measuring set, the time dependence of the membrane potentials was investigated. For steady states, the ∆ΨS was calculated and then the concentration characteristics of this effect were determined for aqueous solutions of NaCl and ethanol. The results obtained from the calculations based on the mathematical model of the gravitational effect are consistent with the experimental results within a 7% error range. It has been shown that a positive or negative gravielectric effect appeared when a density of the solution in the inter-membrane compartment was higher or lower than the density in the outer compartments. The values of the ∆ΨS were in a range from 0 to 27 mV. It was found that, the lower the concentration of solutions in the outer compartments of the two-membrane system (C0), for the same values of Cm/C0, the higher the ∆ΨS, which indicates control properties of the double-membrane system. The considered two-membrane electrochemical system is a source of electromotive force and functions as an electrochemical gravireceptor.

Extraction of triterpene acids from loquat leaves via a novel hydrophobic deep eutectic solvent screened by COSMO-SAC model

Triterpene acids (TTAs) have promising applications in functional food, medicine and other fields. Here, ultrasonic-assisted hydrophobic deep eutectic solvent (HDES) extraction was employed to gain TTAs from loquat leaves. Combining COSMO-SAC model prediction with experimental verification，the HDES, composed of thymol and benzyl alcohol (molar ratio 2:1), was proved to have the highest extraction ability for TTAs. The preliminarily optimized extraction conditions were solid to solvent ratio 1:10 (g/g), temperature 60 °C and extraction time 60 min. Under these conditions, the extraction yield of ursolic acid (the main component of loquat leaf TTAs) was 17.769 ± 0.799 mg/g dry loquat leaf. HDES and TTAs were recovered from HDES extracting solution via gradient elution (60% and 80% ethanol aqueous solution, respectively) based on C18 reverse-phase silica gel column chromatography under low pressure (0.5 MPa). Recovered HDES could be reused for extracting TTAs from loquat leaves directly and had a similar extraction performance compared to fresh HDES. The purity of the obtained crude TTAs sample was 81.18% based on the total contents of maslinic acid (MA), corosolic acid (CA), oleanolic acid (OA) and ursolic acid (UA), with a mass ratio of 11:26:10:53. Crude TTAs sample was further separated by C18 reverse-phase silica gel column chromatography using 80% ethanol aqueous solution as mobile phase under high pressure (15 Mpa). By this mean, CA sample with 69.30% purity (MA to CA mass ratio 7:18) and UA sample with 93.94% purity (OA to UA mass ratio 4:21) were obtained. The in vitro antioxidant ability order of the attained TTAs samples was CA sample > crude TTAs sample > UA sample. This study laid a good scientific basis for applying HDES and C18 reverse-phase silica gel column chromatography in the bioactive component extraction and separation fields. It also provided theoretical basis and technical support for obtainment and utilization of high-purity loquat leaf TTAs in the fields of medicine, functional food, cosmetics and so on.

Theoretical calculations of interfacial properties of high carbon alcohol-hydrocarbon-ethanol-water systems

To obtain the interfacial properties of the system of high carbon alcohol-hydrocarbon mixture extracted by ethanol aqueous solution, theoretical calculations of different high carbon alcohol-hydrocarbon-ethanol-water systems were carried out using the concentration gradient theory (CGT). The results reveal that the high carbon alcohol-hydrocarbon-ethanol-water quaternary system exhibits an enrichment phenomenon of high carbon alcohol and ethanol in the interface and the average relative error between the calculated interface tension values and the experimental measurement values is 13.22 %. It was found that the closer the distribution coefficient is to 1, the higher the high carbon alcohols enrichment degree. In the heptanol system, when the distribution coefficient changes from 0.94 to 0.53 and 2.00, the enriched area decreases from 0.0577 to 0.0289 and 0.0352, respectively. When the mass fraction of high carbon alcohol in the high carbon alcohol-hydrocarbon mixture changes, the interfacial tension is mainly affected by the enrichment of high carbon alcohol in the interface, the higher the enrichment of high carbon alcohol, the lower the interfacial tension; When the solvent ratio and the carbon number of high carbon alcohol changes, the interfacial tension is mainly affected by the concentration of ethanol and high carbon alcohol in the raffinate phase, the higher the concentration of ethanol and high carbon alcohol in the raffinate phase, the higher the polar force of the raffinate phase and the lower the interfacial tension.

Solvent and Crystallization Effects on the Dermal Absorption of Hydrophilic and Lipophilic Compounds

This study probes the mechanisms by which volatile solvents (water, ethanol) and a nonionic surfactant (Triton X-100) influence the skin permeation of dissolved solutes following deposition of small doses onto unoccluded human skin. A secondary objective was to sharpen guidelines for the use of these and other simple solvent systems for dermal safety testing of cosmetic ingredients at finite doses. Four solutes were studied – niacinamide, caffeine, testosterone and geraniol – at doses close to that estimated to saturate the upper layers of the stratum corneum. Methods included tensiometry, visualization of spreading on skin, polarized light microscopy and in vitro permeation testing using radiolabeled solutes. Ethanol, aqueous ethanol and dilute aqueous Triton solutions all yielded surface tensions below 36 mN/m, allowing them to spread easily on the skin, unlike water (72.4 mN/m) which did not spread. Deposition onto skin of niacinamide (32 μg·cm−2) or caffeine (3.2 μg·cm−2) from water and ethanol led to crystalline deposits on the skin surface, whereas the same amounts applied from aqueous ethanol and 2 % Triton did not. Skin permeation of these compounds was inversely correlated to the extent of crystallization. A separate study with caffeine showed the absence of a dose-related skin permeability increase with Triton. Permeation of testosterone (8.2 μg·cm−2) was modestly increased when dosed from aqueous ethanol versus ethanol. Permeation of geraniol (2.9 μg·cm−2) followed the order aqueous ethanol > water ∼ 2 % Triton >> ethanol and was inversely correlated with evaporative loss. We conclude that, under the conditions tested, aqueous ethanol and Triton serve primarily as deposition aids and do not substantially disrupt stratum corneum lipids. Implications for the design of in vitro skin permeability tests are discussed.

Synthesis of water-soluble tetrafunctional urethane acrylate bearing a pentaerythritol core and its radical polymerization behaviors in an aqueous solution

A novel water-soluble tetrafunctional urethane acrylate (TUA) was successfully synthesized by addition reaction of pentaerythritol to 2-isocyanatoethyl acrylate. TUA efficiently underwent radical polymerization and its copolymerization with monofunctional acrylate monomers exhibiting hydrophilicity in an ethanol aqueous solution, affording corresponding networked polymers in high yields. Notably, TUA exhibited much lower volume shrinkage during the radical polymerization compared to a comparative pentaerythritol core based tetrafunctional acrylate containing no urethane bonds. The thermal decomposition temperature of the networked homopolymer, synthesized from TUA, was much higher than those of the linear polymers, synthesized from monofunctional urethane acrylate monomers. TUA is expected to be applied to the development of environmentally sustainable polymer materials.

Highly efficient C@Ni-Pd bifunctional electrocatalyst for energy-saving hydrogen evolution and value-added chemicals co-production from ethanol aqueous solution

Highly efficient C@Ni-Pd bifunctional electrocatalyst for energy-saving hydrogen evolution and value-added chemicals co-production from ethanol aqueous solution

Process Optimization for Aqueous Ethanosolv Pretreatment of Coffee Husk Biomass Using Response Surface Methodology

ABSTRACT This study targeted to optimize process factors using response surface methodology and determining their effect on delignification and cellulose recovery. Optimization of pretreatment conditions with desirability value of 0.828 was done at temperature (A) 150°C, contact time (B) 2 h, and liquid-to-solid ratio (LSR) (C) 15 ml/g. The sample was soaked in an aqueous ethanol solution (48% ethanol). Chemical composition was determined to be 1.87 ± 0.20, 7.03 ± 0.99, 28.05 ± 0.27, 39.29 ± 3.39, and 23.77 ± 3.91 wt% for ash, extractives, lignin, hemicellulose, and cellulose, respectively. Experimental results were validated by comparing actual value with predicted value. The model was verified as the best for improving delignification and cellulose yield. Coefficient of determination (R 2), analysis of variance (ANOVA), response plots, and optimization nodes were used to examine the experimental results. The quadratic equation was used to test the model, and ANOVA was used to evaluate the model’s statistical performance and correctness. Temperature, interaction term (BC), and quadratic terms (A2, B2, and C2) showed significance, while contact time, LSR, and interaction terms (AC and AB) indicated insignificance for cellulose recovery. Temperature, contact time, interaction term (AB), and quadratic terms (B2 and C2) showed significance, but LSR, interaction terms (AC and BC), and quadratic term (A2) showed insignificance for delignification. Pretreatment efficacy for delignification (6.0%) and cellulose recovery (151.80%) were achieved at optimal conditions. The pretreatment method is able to produce cellulose-rich coffee husk residues.

Enhancing the Photocatalytic Performance of BiVO4 for Micropollutant Degradation by Fe and Ag Photomodification

Wider application of BiVO4 (BVO) for photocatalytic water treatment is primarily limited by its modest photocatalytic effectiveness, despite its appropriately narrow band gap for low-cost, sunlight-facilitated water treatment processes. In this study, we have photomodified an isotype BVO, consisting of a tetragonal zircon and monoclinic scheelite phase, with Fe (Fe@BVO) and Ag (Ag@BVO) ionic precursors under UV illumination in an aqueous ethanol solution in order to assess their effect on the opto-electronic properties and effectiveness for the removal of ciprofloxacin (CIP). Fe@BVO failed to demonstrate enhanced effectiveness over pristine BVO, whereas all Ag@BVO achieved improved CIP degradation, especially 1% Ag@BVO. At pH 4 and 6, 1% Ag@BVO demonstrated nearly 24% greater removal of CIP than BVO alone. Photomodification with Fe created surface oxygen vacancies, as confirmed by XPS and Mott–Schottky analysis, which facilitated improved electron mobility, although no distinct Fe-containing phase nor Fe-doping was detected. On the other hand, the introduction of mid-band gap states by oxygen vacancies decreased the reducing power of the photogenerated electrons as the flat band potentials were shifted to more positive values, thus likely negatively impacting superoxide formation. In contrast, Ag-photomodification (Ag@BVO) resulted in the formation of Ag2O/AgO and Ag nanoparticles on the surface of BVO, which, under illumination, generated hot electrons by surface plasmon resonance and enhanced the mobility of photogenerated electrons. Our research underscores the pivotal role of photogenerated electrons for CIP degradation by BiVO4-based materials and emphasizes the importance of appropriate band-edge engineering for optimizing contaminant degradation.

Evaluation of ethanol-based aqueous two-phase systems performance for application in centrifugal partition chromatography (CPC)

Aqueous two-phase systems (ATPS) have recently been proposed for Centrifugal Partition Chromatography (CPC). This type of biphasic system has several advantages over conventional aqueous-organic liquid–liquid systems, namely, high biocompatibility owing to its large water content. The most commonly used ATPS are polymer-based systems. However, owing to their poor phase separation hydrodynamics compared to aqueous-organic systems, the use of short-length water-miscible alcohols has been evaluated as an alternative to polymers. In this study, an ATPS composed of ethanol and dipotassium hydrogen phosphate (K2HPO4) is proposed to overcome the common hydrodynamic drawbacks of polymer-based ATPS. The Ethanol/K2HPO4 system exhibited a very short settling time (ts = 30.85 ± 0.80 s), high interfacial tension (IFT = 6.38 mN/m), significant density differences between the phases (Δρ = 353.40 kg/m3), and low viscosity of the coexisting phases at 25 °C (maximum µ = 3.79 ± 0.11 mPa.s), making it an ideal choice for implementation in CPC apparatus. A comprehensive study of this biphasic system was conducted using CPC equipment by carefully adjusting the operating parameters, specifically, the mobile phase flow rate (F), rotational speed (ω), and mode of operation, that is, ascending (upper phase is mobile) or descending (lower phase is mobile). In this particular CPC equipment, the use of polymers as phase-forming compounds in ATPS resulted in higher CPC pump pressures compared to ethanol or phosphate salt aqueous solutions, thus confirming the superior performance of the ethanol/salt ATPS. The results obtained using this ATPS demonstrated that high F and ω values lead to lower stationary phase retention (SF) and higher backpressures, respectively. SF remained relatively constant and above 50% for F ≤ 6 mL/min but significantly decreased for F > 6 mL/min. This trend confirms that hydrostatically stable conditions can be achieved by employing the Ethanol/K2HPO4 system in the CPC mode by controlling F (i.e., the hydrodynamics of the mobile phase). The partition of the model solutes gallic acid and L-tyrosine was also evaluated using the ethanol/K2HPO4 system. The critical operating CPC parameters were compared, confirming the significant potential of the ethanol/salt ATPS for successful commercial application of this chromatographic technique in the separation of small value-added biomolecules.

Neutron studies of diffusion processes near a singular point in a dilute aqueous solution of ethanol

The problem considered in this work relates to the physics of liquids. Rather, to the physics of dynamic processes in liquids. The method of quasielastic scattering of slow neutrons was used to study the dynamics of molecules of the water-ethanol system as a function of concentration at a temperature of 8 °C and as a function of temperature at a concentration of X = 0.04 molar particles (mol. particl.). The overall coefficient of self-diffusion of molecules D, its single-particle Ds-p and collective Dcoll components, as well as the time of settled life of a molecule in a vibrational state t, are determined. The region of small concentrations was studied in detail, where in the vicinity of concentrations X = 0.04 mol. particl. and X = 0.2 mol. particl. two minima are found in the coefficients D and Ds-p. Time t at these concentrations increases significantly. This indicates a significant decrease in the intensity of the activation mechanism of molecular diffusion at these concentrations, which is quite possibly caused by the binding of water and ethanol molecules into complexes (clusters). Similarly, a deep minimum was found in the D and Ds-p coefficients near the temperature of 4 °С. Time t at this temperature also increases. That is, at a temperature of 4 °C, the intensity of the activation mechanism of the diffusion of solution molecules decreases. Therefore, at a concentration of X = 0.04 mol. particl. and at a temperature of 4°C, a special point exists in the water-ethanol system. However, its position does not coincide with the data on scattering light.

Synthesis, luminescent properties and antibacterial activity of new pyrazoline and pyrimidine derivatives of (2<i>e</i>)-1-biphenyl-3-arylprop-2-en-1-ones

Substituted prop-2-en-1-ones were obtained by the condensation reaction of 1-biphenyl-4-yl-ethanone with aromatic aldehydes in the presence of sodium hydroxide in an aqueous ethanol solution. Subsequent cyclization of the latter with hydrazine hydrate, phenylhydrazine, and thiosemicarbazide in an acidic medium leads to the corresponding pyrazolines. The reaction of amidine hydrochlorides with chalcones in a KOH-ethanol system leads to 2,4,6-trisubstituted pyrimidines. The luminescent and antibacterial properties of the resulting systems was studied.

Supramolecular gelator functionalized liquid metal nanodroplets as lubricant additive for friction reduction and anti-wear

In this work, dopamine n-butenylamide (DBA) modified GLM nanodroplets were prepared via directional ultrasound of bulk liquid metal in ethanol aqueous solution as well as DBA self-assembly, followed by grafting with urea-based gelators via radical polymerization to obtain GLM-based supramolecular gelators (Gelator@GLM). The grafting gelators can impart their good compatibility between the GLM nanodroplets and the base oil, so that the Gelator@GLM nanodroplets can be dispersed in the base oil uniformly and stably for more than 3 weeks. Meanwhile, the tribological properties of Gelator@GLM nanodroplets was significantly enhanced, with a reduction of coefficient of friction (COF) and the wear volume of 41.18% and 92.13%, respectively, when compared with the base oil. Furthermore, Gelator@GLM additives exhibited stable lubrication performance even under variable temperature and frequency conditions. The synergistic effect of GLM nanodroplets and the gels generating a physical adsorption film and a chemically protective film (containing iron and chromium oxides, nitrides and carbides) can be credited with the improved tribological performance.

Acetylcellulose Recovery from Waste Residual for Attenuating Reactive Dye from Aquaculture Waste as a Fascinating Synergistic Ecology Effect

Waste valorization is attracting not only the scientific world but also the world. Acetylcellulose wastes from cigarette filter residuals are signified as the largest global impact of solid waste. Acetylcellulose recycling for desired products is a promising way for environmental management. In this regard, the current investigation is dealing with the immersion of residual filters sequentially into aqueous solutions of alkali and ethanol before water washing, which converts them into a superhydrophobic acetylcellulose adsorbent material. The morphology and characteristics of the acetylcellulose fiber were characterized using a Scanning Electron Microscope (SEM) and Fourier-Transform infrared spectroscopy (FTIR). The adsorption tendency was checked for Levafix Blue dye compromised in an aqueous stream as a model textile polluted effluent. The experimental results exposed that the acetylcellulose fiber displayed a sensible textile dye elimination from the dying stream. Langmuir isotherm is well fitting the adsorption matrix and the reaction follows the 1st-order kinetic model. The so-obtained acetylcellulose fiber showed tremendous efficiency for dye removal from aqueous effluent. The attained maximum monolayer adsorption capacity was recorded as 4.8 mg/g at pH 3.0 and an adsorbent dose of 1 g/L through the isotherm time of 2 h. Also, temperature elevation could increase the adsorption capacity to 5.7 mg/g. Due to this excellent affinity to adsorb dye at an economic wise rate is shown as a promising candidate for textile dye elimination form aqueous effluent.

Synthesis of Hierarchical CdS/NiS Photocatalysts Using Ni-MOF-74 as Template for Efficient Ethanol Conversion and Hydrogen Production under Visible Light.

The conversion of ethanol into high-valuable chemicals and H2 by photocatalytic process provides a sustainable approach to produce carbon-chain-prolonged chemicals and hydrogen energy. In this article, Ni-MOF-74 was added to fabricate the hierarchical CdS/NiS-N composites with an elevated specific surface area during the hydrothermal synthesis of CdS microsphere, and the Ni-MOF-74 facilitate the self-assemble growth of CdS and provide a source of Ni for the formation of NiS. The as-prepared photocatalyst was subjected to photocatalytic ethanol conversion, and the hierarchical composite material CdS/NiS-N (100) formed by adding 100 mg of Ni-MOF-74 exhibits the highest photocatalytic activity and stability in an ethanol aqueous solution with a water content of 10 %. Under visible light irradiation, the conversion rate of ethanol reached 15.2 % at the photocatalytic reaction of 5 h. The selectivity of 2,3-butanediol(2,3-BDO) was 25 %, and the selectivity of acetaldehyde(AA) was 63 %. Through various characterizations, it has been proven that a large specific surface area and the coupling interface between CdS and NiS are key factors in improving photocatalytic performance. This work provides an effective strategy for constructing photocatalysts with coupled cocatalysts/semiconductors and large specific surface areas.

A Comparative Study of Ethanol and Citric Acid Solutions for Extracting Betalains and Total Phenolic Content from Freeze-Dried Beetroot Powder.

This research compares the extraction of betalains (betacyanin and betaxanthin) and total phenolic content using citric acid and aqueous-ethanol solutions. The aim is to find an environmentally sustainable alternative solvent for extracting these compounds from dried beetroot powder. Using citric acid solution as a solvent offers several benefits over ethanol. Citric acid is a weak organic acid found naturally in citrus fruits, making it a safe and environmentally friendly choice for certain extraction processes. Moreover, the use of citric acid as solvent offers biodegradability, non-toxicity, non-flammability, and is cost effective. A full factorial design and response surface methodology (RSM) were employed to assess the effects of extraction parameters (extraction time (5-30 min), extraction temperature (20, 30, 40 °C), pH of citric acid solution (3, 4, 5) and ethanol concentration (10, 20, 30% v/v)). The yield was determined spectrophotometrically and expressed as mg/g of dry powder. The results showed that citric acid solution yielded 85-90% of the ethanolic extract under identical conditions. The maximum yields of betacyanin, betaxanthin, and total phenolic content in citric acid solution were 3.98 ± 0.21 mg/g dry powder, 3.64 ± 0.26 mg/g dry powder, and 8.28 ± 0.34 mg/g dry powder, respectively, while aqueous-ethanol yielded 4.38 ± 0.17 mg/g dry powder, 3.95 ± 0.22 mg/g dry powder, and 8.45 ± 0.45 mg/g dry powder. Optimisation resulted in maximum extraction yields of 90% for betalains and 85% for total phenolic content. The study demonstrates the potential of citric acid as a viable alternative to polar organic solvents for extracting phytochemicals from plant material, providing comparable results to aqueous-ethanol. Artificial Neural Network (ANN) models outperformed RSM in predicting extraction yields. Overall, this research highlights the importance of exploring bio-solvents to enhance the environmental sustainability of phytochemical extraction.

Rapid Estimation of Ethanol Concentration using Acousto‐Optic Diffraction

AbstractFast and accurate determination of ethanol concentration is important in alcohol industries for testing the purity and quality of their products. Here, we demonstrate a quick, robust, and accurate technique to estimate the concentration of ethanol in aqueous solutions. Our method utilizes the principle of diffraction of light in the presence of high frequency ultrasound waves that create diffraction grating in solution. A monochromatic light interacts with this acoustic grating and produces an intensity distribution pattern, which was used to determine the ethanol concentration. We measured ethanol concentrations in various alcoholic solutions and beverages at room temperature with very high accuracy down to 2 % over a concentration range of 30–100 %. The experimental results have been supported with analytical calculations and simulations. We believe that our method will benefit alcohol production industries and lead to the development of portable, inexpensive, and reliable ethanol concentration measurement devices.

Effect of butanol, ethanol and acetone feed composition through activated carbon-containing polydimethylsiloxane pervaporation membrane

The ABE route, whose products are acetone, butanol and ethanol, is an industrial process that has been investigated by the possibility of incorporating renewable resources as inputs of chemical compounds and fuels. In view of the toxicity of 1-butanol to the cells of the fermentation broth, pervaporation by means of a polydimethylsiloxane mixed matrix membrane containing 1 wt% activated carbon was used as an alternative to recover this alcohol simultaneously to its production. Synthetic aqueous solution of acetone, 1-butanol and ethanol was investigated with total organic content varied from 1.5 to 2.7 wt%. Permeate flux and selectivity (separation and enrichment factors) were reported. Regarding the organics transport through the membrane, there was not a linear relation of their content in feed stream and flux. Besides, the permeation sequence did not follow a single transport mechanism. High separation and enrichment factors for acetone and butanol were observed.