Extraction Kinetics Research Articles

Metastable precipitation and ion–extractant transport in liquid–liquid separations of trivalent elements

The extractant-assisted transport of metal ions from aqueous to organic environments by liquid-liquid extraction has been widely used to separate and recover critical elements on an industrial scale. While current efforts focus on designing better extractants and optimizing process conditions, the mechanism that underlies ionic transport remains poorly understood. Here, we report a nonequilibrium process in the bulk aqueous phase that influences interfacial ion transport: the formation of metastable ion-extractant precipitates away from the liquid-liquid interface, separated from it by a depletion region without precipitates. Although the precipitate is soluble in the organic phase, the depletion region separates the two and ions are sequestered in a long-lived metastable state. Since precipitation removes extractants from the aqueous phase, even extractants that are sparingly soluble in water will continue to be withdrawn from the organic phase to feed the aqueous precipitation process. Solute concentrations in both phases and the aqueous pH influence the temporal evolution of the process and ionic partitioning between the precipitate and organic phase. Aqueous ion-extractant precipitation during liquid-liquid extraction provides a reaction path that can influence the extraction kinetics, which plays an important role in designing advanced processes to separate rare earths and other minerals.

Ultrasonic–microwave synergistic liquid–liquid microextraction based on solidified floating organic droplets for extraction of histamine in beer and fish and exploration of the extraction process

It is important to detect the presence of histamine (His) for indicating food quality. To improve the precision and accuracy of histamine detection, this study developed a novel ultrasonic–microwave synergistic liquid–liquid microextraction based on solidified floating organic droplets (UMS-SFO-LLME) to determine His in beer and fish combined with visible spectrophotometry. Through single-factor experiments and response surface Box–Behnken design, the key extraction conditions affecting UMS-SFO-LLME were systematically optimized. The results for the extraction kinetics and thermodynamics indicated that UMS-SFO-LLME is a spontaneous endothermic diffusion extraction process. The linear range of this method in combination with visible spectrophotometry for the determination of His in beer and fish is 0.3–15 mg L−1 and 1–300 mg kg−1, limit of detection is 0.1 mg L−1 and 0.3 mg kg−1, the intra-day precision is 0.86%–1.22% and 0.98%–2.11%, and the inter-day precision is 0.81%–1.75% and 1.45%–2.32%, respectively. UMS-SFO-LLME is an efficient, green and economical sample pretreatment method for determination of His in beer and fish samples.

Kinetics of extraction and degradation of pectin derived compounds from onion skin wastes in subcritical water

In this work the valorization of onion skin wastes (OSW) as a source of the pectic oligosaccharides (POS), prebiotic hydrocolloids, using subcritical water (SubW) was thoroughly studied and modeled (using the Panchev's model) in a batch extractor at temperatures up to 165 °C and extraction times up to 180 min. The extraction of pectin derived compounds was notably sensitive to both variables, with the most favorable extraction rates occurring within a severity factor (logR0) range of 2.8–3.1. The highest recovery, 32 g of OGalA per 100 g of raw material, was achieved at 135 °C for 100 min. This process yielded various families of compounds categorized by their weight average molecular weight (Mw), with 85 kDa being the most prevalent, followed by 27, 17, and 7 kDa. The changes in Mw as a function of time and temperature was modeled using the Emsley equation, which enabled the prediction of POS molecular weight based on extraction conditions, as well as the calculation of the energy of activation for pectin derived compounds degradation (116 ± 2 kJ/mol). Additionally, along with the loss in molecular weight, the presence of degradation products such as formic acid and furfural increased with the intensity of the extraction conditions. In summary, the hydrothermal extraction conducted at temperatures between 125 and 135 °C facilitated the retrieval of POS with MW ranging from 7 to 85 kDa. This stands in contrast to the high MW (>300 kDa) and linear pectin obtained through conventional acid-water extraction processes.

Ionic liquid microwave-assisted hydrodistillation extraction of Angelica sinensis essential oil and its own anti-inflammatory and antioxidant activities

In this study, ionic liquid microwave-assisted hydrodistillation (IL-MAHD) was employed to overcome the challenges of substantial emulsification and low extraction yield which occur in the extraction process of Angelica sinensis essential oil (AEO). Additionally, an online detection system was introduced into the AEO extractor to enable real-time monitoring during the extraction process. Optimal conditions were determined as follows: material-to-liquid of 1:10, ionic liquid concentration of 0.5%, microwave power of 400 W, extraction time of 4 h, condensation temperature of 20 °C, and cooling temperature of 40 °C. Under these optimized conditions, the AEO yield reached 0.7707%, marking a 1.4066-fold increase compared to microwave-assisted hydrodistillation (MAHD) and a 3.7615-fold increase compared to hydrodistillation (HD). Meanwhile, IL-MAHD exhibited the highest relative content of (Z)-ligustilide (73.424%), and the corresponding AEO displayed significant anti-inflammatory and antioxidant effects at concentrations of 7.8125, 15.625, and 31.25 µg/g. The results of extraction kinetics and online monitoring suggested that the IL-MAHD achieved the fastest extraction yield of AEO. This study provides a new perspective on exploring a potential cost-efficient technology for the industrial extraction of essential oils.

Extraction Kinetics of Pyridine, Quinoline, and Indole from the Organic Phase with Natural Deep Eutectic Solvents and Separation Study Using a Centrifugal Extractor

In this study, the kinetics of extracting pyridine, quinoline, and indole from model fuels using natural deep eutectic solvents (NaDES) composed of carboxylic acids, xylitol, and water were investigated under static conditions. This research marks the first examination of extraction kinetics in this context. The key kinetic parameters of the extraction process were identified. Notably, it was observed that the mass transfer coefficient for indole was in the range of 3.4 × 10−6 to 1.2 × 10−6, depending on NaDES. That is significantly lower, by an order of magnitude, than for pyridine and quinoline under identical experimental conditions. The study revealed that, under specific conditions, where thermodynamic equilibrium for indole cannot be reached, it becomes possible to achieve kinetic separation of the components. The presented experimental data obtained on a centrifugal extractor showed a decrease in the degree of indole extraction with increasing flow: Extraction efficiency decreased from 63% at a flow rate of 0.05 L/h to 18% at 0.8 L/h. Moreover, the research indicated that, during indole extraction, the mass transfer coefficient in a centrifugal extractor was 1.3 × 10−4, which is two orders of magnitude higher than under static conditions. The study underscores the potential utility of the proposed extraction systems based on environmentally friendly NaDES, comprised of carboxylic acids and xylitol, for the kinetic separation of various classes of heterocyclic compounds. Overall, the research provides valuable insights into the kinetics of extraction and the potential applications of ‘green’ NaDES in the separation of heterocyclic compounds from organic liquids.

Investigation of inhibition kinetics of various plant extracts on polyphenol oxidase enzyme from Paulownia Tomentosa and binding mechanism by molecular docking

Polyphenol oxidase/tyrosinase enzyme, which contains binuclear copper clusters play an important role in melanogenesis and enzymatic browning. Therefore, its inhibitors can be attractive in cosmetics and medicinal industries as depigmentation agents and also in food and agriculture industries as antibrowning compounds. Our aim in this study is to find natural plant extracts that will inhibit the polyphenol oxidase enzyme. The inhibitory effects of Verbascum thapsus, Tanacetum vulgare, Solanum nigrum and Datura stramonium herbal plant extracts obtained from Kosovo on the polyphenol oxidase enzyme activity were investigated. Polyphenol oxidase from the Poulownia tomentosa plant was purified using the three-phase purification method. It is determined that T. vulgare extract showed the most effective inhibitory effect with 0.43 mg/mL IC50 value. In order to explain and support the binding mechanism of the best inhibitor extract, the phenolic content of the T. vulgare extract was determined by LC-MS/MS and the mechanism of the inhibitory effect was explained by performing a molecular docking study for the phenolic compounds it contained at the highest rate.

Effect of Single-Crystal TiO2/Perovskite Band Alignment on the Kinetics of Electron Extraction.

The kinetics of electron extraction at the electron transfer layer/perovskite interface strongly affects the efficiency of a perovskite solar cell. By combining transient absorption and time-resolved photoluminescence spectroscopy, the electron extraction process between FA0.83Cs0.17Pb(I0.83Br0.17)3 and TiO2 single crystals with different orientations of (100), (110), and (111) were probed from subpicosecond to several hundred nanoseconds. It was revealed that the band alignment between the constituents influenced the relative electron extraction process. TiO2(100) showed the fastest overall and hot electron transfer, owing to the largest conduction band and Fermi level offset compared to FA0.83Cs0.17Pb(I0.83Br0.17)3. It was found that an early electron accumulation in these systems can have an influence on the following electron extraction on the several nanosecond time scale. Furthermore, the existence of a potential barrier at the TiO2/perovskite interface was also revealed by performing excitation fluence-dependent measurements.

Mechanical and morphological bond line properties of silver birch wood pretreated by aqueous extraction

While bonding for structural applications in Europe was limited to only a few softwood species in the past, forest alterations toward more climate stability will increase the diversity of tree species. This requires an understanding of typal wood-adhesive interactions. To help facilitate birch wood bonding, its cold-water soluble extractives and their effects on mechanical performance and bond line morphology were studied using water-borne melamine-urea-formaldehyde (MUF) and hydrophobic solvent-free polyurethane (PUR) adhesives. Extractives classes were identified via mass spectrometry and their concentration and extraction kinetics were evaluated. The analysis revealed that the mechanical properties of the bond line were essentially unaffected by extraction when using the hydrophobic PUR adhesive. Increased degrees of extraction resulted in reduced MUF penetration, and slightly thicker bond lines, however, the mechanical results indicate improved performance, indicating fewer defects in the cured adhesive network.

Elevated temperature extraction of β-carotene from freeze-dried carrot powder into sunflower oil: Extraction kinetics and thermal stability.

β-Carotene, a precursor of vitamin A, can alleviate the deficiency of this vitamin prevalent worldwide. Earlier research studies have addressed the extraction of β-carotene at relatively low temperatures (up to 70°C) due to its perceived instability at higher temperatures, as a result of which extraction rates recorded are relatively low. This study models the net rate of β-carotene extraction by considering both extraction and degradation kinetics. The model developed, which accounts for degradation occurring in solid and extract phases, has been experimentally validated for the extraction of β-carotene from freeze-dried carrot powder into sunflower oil over a range of temperatures 90-150°C. This study also gives insights into the application of sunflower oil as a carrier for β-carotene during cooking and food processing, by monitoring and modeling the thermal degradation and isomerization of β-carotene at temperatures up to 220°C. The modeling of extraction kinetics shows that it is possible to achieve viable extraction rates by employing temperatures in the range (90-150°C) for relatively short times (<5min). The degradation kinetics shows that almost 75% of the β-carotene can survive heating at 180°C for 10min-indicating the possibility of using β-carotene enriched edible oils for frying. This study also reports on the formation of three isomers of β-carotene identified using HPLC: trans-, 9-cis, and 13-cis. The reaction network model developed in this study was able to account for the transient variation of the concentration of all three isomers. PRACTICAL APPLICATION: β-Carotene is a precursor of vitamin A and its consumption can potentially alleviate the deficiency of this vitamin prevalent worldwide. This study validates a model for the extraction of β-carotene in sunflower oil, which takes into account extraction as well as degradation occurring during extraction, so that a rational method is available for the design of efficient extractors for this purpose. This paper also establishes the thermal stability of β-carotene under frying conditions by quantifying its thermal degradation as well as isomerization.

Antibacterial activity evaluation of cambuí extract against multi-resistant Enterococcus faecium

Bacterial resistance is a global public health issue. Among these pathogens, Enterococcus faecium nosocomial has been highlighted due to its potential to cause bacteremia infections. The incidence of resistant Enterococcus faecium bacteremia has enhanced over time, thereby, it has caused high rates of mortality. Hence, it led to the interest in natural drugs. Plant extracts from the Myrtaceae family have a broad-spectrum antimicrobial action. Among the plants of this family, we can highlight cambuí, due to its wide variety of bioactive compounds such as phenolic compounds. Polyphenols are bioactive molecules that can inhibit the growth of resistant bacteria such as Enterococcus faecium. For this, the present study aimed to obtain bioactive extracts from cambuí using pressurized hot water to grow inhibition of multi-resistant Enterococcus faecium nosocomial. In the present study, antibacterial compounds were obtained after extraction kinetics over 120 minutes at a temperature of 50º C, a flow rate of 1 mL/min-1, and a constant pressure of 200 bar using water as the extraction solvent. Flavonoids and other phenolic compounds from cambuí extracts were quantified by spectrophotometric methods. The TSA using the well-diffusion method was used to verify the sensitivity of the bacterium Enterococcus faecium against cambuí aqueous extract. The results showed that the best extraction time was 60 minutes using 60 mL of water. The cambuí aqueous extract showed a relevant amount of flavonoids and other phenolic compounds, hence, this extract was able to inhibit the growth of the bacterium Enterococcus faecium resistant to Ampicillin, Imipenem, Vancomycin, and Teicoplanin.

Carbon-Extraction-Induced Biaxial Strain Tuning of Carbon-Intercalated Iridium Metallene for Hydrogen Evolution Catalysis.

Metallene materials with atomic thicknesses are receiving increasing attention in electrocatalysis due to ultrahigh surface areas and distinctive surface strain. However, the continuous strain regulation of metallene remains a grand challenge. Herein, taking advantage of autocatalytic reduction of Cu2+ on biaxially strained, carbon-intercalated Ir metallene, we achieve control over the carbon extraction kinetics, enabling fine regulation of carbon intercalation concentration and continuous tuning of (111) in-plane (-2.0%-2.6%) and interplanar (3.5%-8.8%) strains over unprecedentedly wide ranges. Electrocatalysis measurements reveal the strain-dependent activity toward hydrogen evolution reaction (HER), where weakly strained Ir metallene (w-Ir metallene) with the smallest lattice constant presents the highest mass activity of 2.89 A mg-1Ir at -0.02 V vs reversible hydrogen electrode (RHE). Theoretical calculations validated the pivotal role of lattice compression in optimizing H binding on carbon-intercalated Ir metallene surfaces by downshifting the d-band center, further highlighting the significance of strain engineering for boosted electrocatalysis.

No sex differences in oxygen uptake or extraction kinetics in the moderate or heavy exercise intensity domains.

The integrative response to exercise differs between sexes, with oxidative energy contribution purported as a potential mechanism. The present study investigated whether this difference was evident in the kinetics of oxygen uptake (V̇o2) and extraction (HHb + Mb) during exercise. Sixteen adults (8 males, 8 females, age: 27 ± 5 yr) completed three experimental visits. Incremental exercise testing was performed to obtain lactate threshold and V̇o2peak. Subsequent visits involved three 6-min cycling bouts at 80% of lactate threshold and one 30-min bout at a work rate of 30% between the lactate threshold and power at V̇o2peak. Pulmonary gas exchange and near-infrared spectroscopy of the vastus lateralis were used to continuously sample V̇o2 and HHb + Mb, respectively. The phase II V̇o2 kinetics were quantified using monoexponential curves during moderate and heavy exercise. Slow component amplitudes were also quantified for the heavy-intensity domain. Relative V̇o2peak values were not different between sexes (P = 0.111). Males achieved ∼30% greater power outputs (P = 0.002). In the moderate- and heavy-intensity domains, the relative amplitude of the phase II transition was not different between sexes for V̇o2 (∼24 and ∼40% V̇o2peak, P ≥ 0.179) and HHb + Mb (∼20 and ∼32% ischemia, P ≥ 0.193). Similarly, there were no sex differences in the time constants for V̇o2 (∼28 s, P ≥ 0.385) or HHb + Mb (∼10 s, P ≥ 0.274). In the heavy-intensity domain, neither V̇o2 (P ≥ 0.686) or HHb + Mb (P ≥ 0.432) slow component amplitudes were different between sexes. The oxidative response to moderate- and heavy-intensity exercises did not differ between males and females, suggesting similar dynamic responses of oxidative metabolism during intensity-matched exercise.NEW & NOTEWORTHY This study demonstrated no sex differences in the oxidative response to moderate- and heavy-intensity cycling exercise. The change in oxygen uptake and deoxyhemoglobin were modeled with monoexponential curve fitting, which revealed no differences in the rate of oxidative energy provision between sexes. This provides insight into previously reported sex differences in the integrative response to exercise.

Comparative extraction and antioxidant potential of bioactive compounds from Fucus vesiculosus: Kinetic modeling and UPLC-Q-TOF-MS phenolic profiling

This study explores efficient bioactive compounds extraction from Fucus vesiculosus (FV) seaweed using Ultrasound-assisted extraction (UAE) and Solid Liquid Extraction (SLE). Varied ultrasound intensities (UI) (58.8, 103.1 and 164.5 kW m−2 for U1, U2 and U3, respectively) were employed, and Peleg's model simulated extraction kinetics, revealing UAE's remarkable 10-min equilibrium contrasted with SLE's 3 h, showcasing UAE's time efficiency. UAE, particularly at U3, yielded significantly higher Total Phenolic Content (TPC) and Uronic Acid Content (UAC) compared to SLE, reaching maximum concentrations of 2.26 ± 0.01 g PGE 100 g−1 DFV and 7.87 ± 0.11 g GAE 100 g−1, respectively. Increased UI enhanced DPPH and ABTS antioxidant activities, while low UI resulted in higher FRAP values. After 20 min of extraction, U3 demonstrated superior DPPH scavenging activity (5.75 ± 0.23 μM TE g−1 DFV), surpassing that of SLE after 20 h of extraction (4.76 ± 0.11 μM TE g−1 DFV). Additionally, U3 displayed elevated ABTS values (8.92 ± 0.33 μM TE g−1 DFV) compared to 6.46 ± 0.41 μM TE g−1 DFV for SLE, with no significant difference observed in FRAP values. These results highlight U3's enhanced antioxidant potential in comparison to SLE. The chromatographic analysis identified six main compounds through UPLC-Q-TOF-MS and HPLC. Higher concentrations of phloroglucinol, gallic acid, catechin, protocatechuic acid, and chlorogenic acid were observed in U3. However, SLE exhibited a higher ferulic acid content. Future research aims to explore phloroglucinol derivatives and FC, contributing to FV' potential applications.

Extraction of Alpha-cypermethrin Pesticides from Aqueous Solution by Emulsion Liquid Membrane

This research examines the emulsion liquid membrane (ELM) extraction efficiency and stability to abstraction of alpha-cypermethrin pesticides from aqueous solution when blended surfactants are used in the liquid membrane composition. The stability of the membrane was examined in the aspect of the emulsion breakdown time and distribution of droplet size. The ingredients employed in ELM were Span80 (sorbitan monooleate) and Tween80 (polyoxyethylene sorbitan monooleate) as surfactants and a mixture of kerosene, sunflower oil (3:7) as diluents and stripping agent was used sodium hydroxide (NaOH). Some parameters were assessed, including the value of Hydrophilic Lipophilic Balance (HLB), blended surfactant concentration, homogenizer speed, emulsification time, and NaOH concentration as a stripping agent. According to the results, a stable emulsion was created at HLB (5.37), blended surfactant 3 % (w/v), 12,700 rpm of homogenizer speed, 9 min of emulsification time, and 0.05 N of NaOH. Under these circumstances, 89.2 % of the alpha-cypermethrin was extracted with 1.8 % emulsion breakage. As a result, the combinations of (Span80 with Tween80) have enormous potential as surfactants and they can improve the stability of the emulsion. Additionally, completed was mass transfer investigation and extraction kinetics

Layered charge separation in surface boron doped copper with phosphate groups boosts the electrochemical uranium extraction from seawater

Electrochemical uranium extraction from seawater is an attractive project for sustainable nuclear industry, whereas the active sites of electrode materials require further promotion on uranyl binding to increase the efficiency and kinetics of uranium extraction. Herein, we construct a strategy of layered charge separation in surface boron-doped copper with surface phosphate ions (B:Cu-PO4) for charge-enhanced uranyl binding and extraction in seawater. The B atoms were demonstrated to decrease the negative charge in surface Cu atoms and increase the negative charge in outer O atoms of PO43- groups, thus enhancing the uranyl binding. In a real seawater experiment, the B:Cu-PO4 extracted 24.9 μg of uranium from 10 L of seawater. Such performance corresponded to a considerable extraction capacity of 2.1 mg/g per day, which outperformed most of the state-of-the-art materials. The successful construction of charge separation in B:Cu-PO4 broadened the material design for uranium extraction from real seawater.

A wearable gait lab powered by sensor-driven digital twins for quantitative biomechanical analysis post-stroke.

Commonly, quantitative gait analysis post-stroke is performed in fully equipped laboratories housing costly technologies for quantitative evaluation of a patient's movement capacity. Combining such technologies with an electromyography (EMG)-driven musculoskeletal model can estimate muscle force properties non-invasively, offering clinicians insights into motor impairment mechanisms. However, lab-constrained areas and time-demanding sensor setup and data processing limit the practicality of these technologies in routine clinical care. We presented wearable technology featuring a multi-channel EMG-sensorized garment and an automated muscle localization technique. This allows unsupervised computation of muscle-specific activations, combined with five inertial measurement units (IMUs) for assessing joint kinematics and kinetics during various walking speeds. Finally, the wearable system was combined with a person-specific EMG-driven musculoskeletal model (referred to as human digital twins), enabling the quantitative assessment of movement capacity at a muscle-tendon level. This human digital twin facilitates the estimation of ankle dorsi-plantar flexion torque resulting from individual muscle-tendon forces. Results demonstrate the wearable technology's capability to extract joint kinematics and kinetics. When combined with EMG signals to drive a musculoskeletal model, it yields reasonable estimates of ankle dorsi-plantar flexion torques (R 2=0.65±0.21) across different walking speeds for post-stroke individuals. Notably, EMG signals revealing an individual's control strategy compensate for inaccuracies in IMU-derived kinetics and kinematics when input into a musculoskeletal model. Our proposed wearable technology holds promise for estimating muscle kinetics and resulting joint torque in time-limited and space-constrained environments. It represents a crucial step toward translating human movement biomechanics outside of controlled lab environments for effective motor impairment monitoring.

No Combined Effect of Caffeinated Chewing Gum and Priming Exercise on Oxygen Uptake and Muscle Near-Infrared Spectroscopy-Derived Kinetics: A Double-Blind Randomized Crossover Placebo-Controlled Trial in Cyclists.

This study aimed to investigate the effects of caffeine ingestion by chewing gum (GUMCAF) combined with priming exercise on pulmonary oxygen uptake (V˙O2) and near-infrared spectroscopy-derived muscle oxygen extraction (HHb + Mb) kinetics during cycling performed in a severe-intensity domain. Fifteen trained cyclists completed four visits: two under a placebo gum (GUMPLA) and two under GUMCAF ingestion. Each visit consisted of two square-wave cycling bouts at Δ70 intensity (70% of difference between the V˙O2 at first ventilatory threshold and V˙O2max) with duration of 6min each and 5min of passive rest between the bouts. The GUMPLA or GUMCAF (400mg) was chewed for 5min, 12min before the first Δ70 bout in a randomized double-blind procedure. The fundamental phase and slow component of HHb + Mb and V˙O2 kinetics were evaluated. For HHb + Mb kinetics, regardless of ingested gum, priming exercise effects occurred on the time constant (GUMCAF 16.0 ± 4.0 vs. 13.9 ± 2.9s; GUMPLA 15.7 ± 6.1 vs. 13.2 ± 2.5s), amplitude, slow component, time delay, and mean response time parameters (p ≤ .032). For V˙O2 kinetics, there were significant effects of bouts on the amplitude, slow component, end V˙O2, and the gain kinetics parameters (p < .017). Baseline V˙O2 was higher during GUMCAF than GUMPLA (p = .020). No significant effects occurred for the interaction between gum and bout in any parameter of V˙O2 or HHb + Mb kinetics. Therefore, unlike the priming exercise in severe-intensity exercise, GUMCAF is not an effective strategy for improving V˙O2 or HHb + Mb kinetics acceleration.

Enhanced photoelectrochemical water splitting performance of α-Fe2O3 photoanodes through Co-modification with Co single atoms and g-C3N4.

The practical application of α-Fe2O3 in water splitting is hindered by significant charge recombination and slow water oxidation. To address this issue, a CoSAs-g-C3N4/Fe2O3 (CoSAs: cobalt single atoms) photoanode was fabricated in this study through the co-modification of CoSAs and g-C3N4 to enhance photoelectrochemical (PEC) water splitting. The coupling between g-C3N4 and α-Fe2O3 resulted in the formation of a heterojunction, which provided a strong built-in electric field and an additional driving force to mitigate charge recombination. Moreover, g-C3N4 served as a suitable carrier for single atoms, which effectively anchored CoSAs through N/C coordination. The highly dispersed CoSAs provided abundant active sites, which further promoted surface holes extraction and oxidation kinetics, resulting in higher PEC performance and photostability. This study indicates the benefits of these collaborative strategies and provides more efficient designs for solar energy conversion in PEC systems.

Kinetic features of solvent extraction by N,O-donor ligands of f-elements: a comparative study of diamides based on 1,10-phenanthroline and 2,2'-bipyridine.

A variant of microfluidic setup design for the study of extraction kinetics has been proposed. Mass transfer constants for Am(III) and Eu(III) and observed rate constants were obtained for N-,O-donor ligands featuring phenanthroline and bipyridyl cores. The possibility of determining rate constants for cations independently of each other makes it possible to observe the kinetic effect of separation. The extraction rate was found to be lower for the bipyridyl ligand, compared to phenanthroline. The values of the rotation barriers for the ligands were calculated using the DFT method. The values correlate with the obtained low extraction rate for the bipyridyl ligand. Also, crystallographic data showing anti-conformation for the bipyridyl ligand align with the kinetic data. Surface tension was also determined for the systems with the studied ligands. It is shown that at equal ligand concentrations, the value of surface tension agrees with the extraction rate. Furthermore, it is shown that for the bipyridyl ligand, prior contact of the organic phase with nitric acid significantly affects the surface tension.

Obtaining an Oily Ingredient Rich in PUFAS and Tocopherols and a High-Nutritional-Value Flour from Beans (Phaseolus vulgaris L.) by Supercritical CO2 Extraction.

The objective of this work was to carry out a preliminary study of the fractionation by supercritical CO2 (sc-CO2) extraction of two varieties of Peruvian beans (Phaseolus vulgaris L.), white (WB) and red (RB), to obtain two novel products: an oil rich in essential fatty acids and tocopherols and a defatted flour with high nutritional value and amino acids. The extraction temperature and pressure were optimized using the response surface methodology (RSM) and the extraction kinetics were optimized using the Spline equation. The results revealed that the best extraction conditions for WB and RB were 396.36 Bar, 40.46 °C, with an efficiency of 1.65%; and 391.995 Bar, 44.00 °C, with an efficiency of 1.12%, respectively. The WB and RB oils presented a high degree of polyunsaturation (63.2 and 52.8%, respectively), with oleic, linoleic, and linolenic fatty acids prevailing. Gamma-tocopherol was the predominant antioxidant in both oils. The residual flours (WB and RB) obtained after extraction with sc-CO2 had a high average content of proteins (23%), carbohydrates (61%), and minerals (3%). The limiting amino acids of WB were: Fen + Tyr, Leu, Lys, and in RB, only Leu was limiting. The viscosity of the solutions (20%) of the WB and RB flours mainly adjusted to the Waele's Ostwald model (r = 0.988). It is concluded that both products (oil and bean flour) obtained in an optimized manner using an eco-friendly technology with sc-CO2 have high nutrient and bioactive component content and can be used in the development of new ingredients and healthy foods of plant origin.