Search

The weed

In this study, we considered changes in the surface chemistry after introducing fluorine into the surface layer of nanoporous activated carbon (BAU) produced from the birch wood. Here, we examined the BAU treated with 1,1,1,2-tetrafluoroethane at the selected temperature in the range of 400–800 °C. Diverse methods, including chemical analysis, nitrogen adsorption–desorption, SEM–EDS, XPS, and 19F solid-state NMR, were used for the characterization of the prepared materials. It was found that one can introduce from 0.17 to 0.42 mmol of F per gram of BAU using fluoroalkylation at 400–500 °C. Increasing the temperature to 600 °C increases the fluorination efficiency, and the relatively high fluorine content of 1.86 mmol of F per gram of BAU can be reached. At least three group types, namely, C–F, CF2, and CF3 groups, were found by XPS and 19F solid-state NMR after such treatment. The content of “semi-ionic” fluorine drastically increases in the surface layer after high-temperature fluoroalkylation at 700 °C and 800 °C. This “semi-ionic” fluorine, in the form of C–F and CF2 groups, is directly conjugated with the π-electron system of the carbon matrix.

Here we report on the application of Mentha piperita L. extract mediated synthesis of gold nanoparticles (AuNPs) with a response in the infrared range. Chromatographic studies showed the extract of M. piperita contains secondary metabolites typically acting as reducing and stabilizing agents. To shed light on the kinetic regularities of the phytosynthesis, we examined the formation of Au nanocolloids in situ considering the impact of the content of reagents: the extract (0.25 mg/ml of dry matter) and HAuCl4 (0.025–0.975 mM) were investigated in the time range 1–75 min. The formation of non-spherical AuNPs is confirmed by TEM and UV–Vis characterization of nanocolloids. UV–Vis spectroscopy showed surface plasmon resonance peaks at 534 and > 900 nm drifting into the infrared range with time and composition of reacting mixtures. The sizes of AuNPs according to the protocol varied from 10 to near 200 nm. TEM showed pseudo-spherical, triangular, and hexagonal AuNPs. Non-ideal surface relief by AFM data for large triangular and hexagonal AuNPs and structural imperfections from HRTEM studies are demonstrated. Kinetic studies showed S-shaped kinetic curves for the reaction of HAuCl4 and the plant extract. All effective constants found for the process of NPs forming can be explained by the more intense formation of large AuNPs and by the formation of NPs of a different shape with a different absorption spectrum at the same time.

Certain limitations of obtaining metal nanoparticles with the use of synthetic chemicals have sparked a great interest in scientists to develop green synthesis procedures which use non-toxic and eco-friendly reagents and wastes. Essential oils have the potential to simultaneously act as reducing agents and stabilizers for the synthesis of metal nanoparticles. In the present work, we have synthesized gold nanoparticles (AuNPs) using clove oil (Syzygium aromaticum L. essential oil) as the main reducing agent and stabilizer. The AuNPs solutions were characterized by UV–VIS spectroscopy, and the isolated solid AuNPs were analyzed by Fourier transformed infrared spectroscopy. Various reactivity descriptors determined in terms of Conceptual Density Functional Theory, for the 16 predominant components of clove oil, have been calculated by using the quantum chemical B3LYP/6-311G** level of theory. With the aim to validate the chosen theoretical method, the calculated infrared spectra have been compared with the available experimental spectra. Moreover, the active centers for nucleophilic and electrophilic attacks have been identified through the analysis of atomic partial charges and Fukui function indices. The obtained theoretical results should be considered as a starting point for the prediction of the appropriateness of essential oils for the direct green synthesis of metal nanostructures.

Ukraine is on the invasion front of spotted-wing Drosophila suzuki (Matsumura, 1931) spreading in Europe. Despite this globally important pest was confirmed only on the southernmost tip of its territory, recently published species distribution models expect its occurrence also in other Ukrainian regions. Therefore, we conducted two-year monitoring (2018-2019) during the whole fruit ripening season; samples were collected on the whole Ukrainian territory; standard bait traps and active capture by an insect net were employed. Individuals of the species were recorded only at the end of the vegetation season (August–October) and only in the westernmost part of Ukraine (Transcarpathian region); in the region predicted by recent ecological niche modeling. The late occurrence of D. suzuki probably reflects the presence of suitable food/fruit for the larvae at the end of the growing season. Our results confirm the importance of monitoring of this pest, together with the investigation of factors that may affect its invasion.

In the present article, we reported the application of the extract of leaves from Solidago canadensis L. for the green synthesis of triangular and hexagonal gold nanoparticles (AuNPs). The phytochemical characterization, by reaction with HAuCl4 solutions, showed that the extract of Solidago canadensis L. contained the secondary metabolites that can act both as reducing and as stabilizing agents. For the synthesis of AuNPs, the effects of the HAuCl4 concentration (0.25–0.975 mM) and the reaction time (10–180 min) were investigated. The formation of AuNPs is confirmed by the color change from yellowish to purple-red. Photoluminescence measurements of Au nanocolloids showed a continuous emission band ranging from violet to red. UV–Vis characterization of AuNPs in the prepared nanocolloids showed surface plasmon resonance peaks at 530 and > 870 nm. TEM revealed that the AuNPs are in the range of 8–200 nm, they have spherical, triangular, and hexagonal forms of varying sizes. AFM and STM showed a non-ideal relief of large triangular and hexagonal gold nanoprisms. The EDX analysis, XRD and SAED patterns confirmed the face-center cubic structure of AuNPs.

In the present work, we report, for the first time, the production of stable nanocolloids of highly monodisperse silver and gold nanoparticles (AgNPs and AuNPs) using phytosynthesis approach. With the aim to eliminate misinterpretations associated with the use of usually applied crude plant extracts, the presented study was focused on the use of polyphenolic fraction isolated from elderberry fruits (Sambucus nigra L.) for the synthesis. Obtained AgNPs and AuNP were characterized by UV–Vis and FTIR spectroscopy, DLS and TEM. We observed unexpectedly high capability of the natural polyphenols not only to form monodisperse nanoparticles but also to stabilise the concentrated nanocolloids (539 mg/L AgNPs and 739 mg/L AuNPs) for at least two years. Moreover, AgNPs showed strong antibacterial properties against pathogenic bacterial strains Staphylococcus aureus and Escherichia coli (inhibited after 15 min and totally stopped growth after 3 and 5 h at 3.125 mg/L concentration).

In the present article, we showed the effect of ultrasonic treatment on the thermal oxidation of detonation nanodiamonds (DNDs) by considering the kinetic aspect of their thermal stability in the air, in the framework of the classical Arrhenius approach. Nanostructures and surface chemistry of the pristine, ultrasonicated, and oxidized DNDs were studied by miscellaneous physical techniques to clarify the origin of the effect. Ultrasonic treating decreases the heterogeneity of aggregated nanoparticles and removes admixtures and non-diamond carbon from the surface interface of nanodiamond grains. After thermal oxidation that followed ultrasonication treatment, the size-reduction of nanodiamond crystals caused the annihilation of nitrogen-vacancy centers and led to photoluminescence quenching. Because the number of surface defects reacting with air oxygen decreases after the ultrasonic treatment, the thermal stability of DND nanopowders towards oxidative treatment shows an increase.

Environmental pollution by toxic metals is a common ecological problem. Chromium and copper compounds released into the environment as a result of human-made stress pose a serious threat to living organisms. Phytoremediation is a promising method of toxic metals removal from contaminated sites. The concentration of metals in grass biomass—in the roots and aerial parts—was determined by X-ray fluorescence analysis. The estimation of numbers of microorganisms was conducted by a tenfold dilution and spread-plating method. It was shown that lawn grass accumulated from 69.1 ± 13.2 to 497.7 ± 74.1 mg/kg Cu and Cr during the growth in the contaminated soil with 50, 100, and 200 mg/kg of metals. In general, there was a pattern of accumulation of copper in the aerial part of the grass and chromium in the roots. Thus, the total copper concentration in the aerial part ranged from 105.2 ± 23.8 to 497.7 ± 74.1 mg/kg of plant biomass. The total chromium concentration in the roots ranged from 156.4 ± 47.9 to 426.8 ± 62.5 mg/kg. The viability of the soil microbiome was not inhibited at such metal concentrations. The obtained data allow lawn grass to be considered as promising for the phytoremediation of contaminated areas.

Plants of the Ambrosia genus are invasive and cause many ecological problems, including the oppression of the growth of agricultural crops and native plants, land depletion, and the production of strong allergens. The use of weeds as a sustainable feedstock for biogas production, either methane or hydrogen, is a promising way to fulfill the energy needs of the current generation, eliminate the depletion of non-renewable carbon resources, and preserve the ecosystem degradation caused by invasive species impacts. A diversified microbial community was used as inoculum and Ambrosia artemisiifolia L. biomass as a substrate for anaerobic degradation and methane production. In this regard, the development of biotechnological approaches to ragweed degradation will promote the integration of new renewable energy systems. Herein, we have shown the high effectiveness of combining the processes of anaerobic degradation of plant biomass for methane production and detoxification of meal-containing model sewage by a diversified microbial community. Thus, the maximum methane yield was 56.0 L kg−1 TS. The presence of 500 mg L−1 Cu(II) slightly inhibited methane synthesis, and the methane yield was 38.4 L kg−1 TS. In contrast to a diversified microbial community, the natural microbiome of ragweed almost did not synthesize methane and did not degrade plant biomass (Kd = 2.3). Methanogens effectively immobilized Cr(IV), Cu(II), and Fe(III) during ragweed fermentation at initial concentrations of 100–200 mg L−1. The obtained results showed the high effectiveness of applying a diversified microbial community in a sewage treatment plant for the degradation of a noxious plant, Ambrosia artemisiifolia L.

The accumulation of various types of waste containing both organic and inorganic metal-containing compounds is extremely hazardous for living organisms. The possibility of polymer degradation, biohydrogen synthesis, and metal detoxification via the dark fermentation of model potato waste was investigated. For this purpose, the strict anaerobic strain was isolated and identified as Clostridium butyricum. The high efficiency of dark hydrogen fermentation of potatoes with yield of hydrogen in 85.8 ± 15.3 L kg−1 VSpotato was observed. The copperand chromium salts solutions were added to the culture fluid to obtain the concentrations of 50, 100, and 200 mg L−1 Cu(II) and Cr(VI) in the active phase of growth (19 h of cultivation). Metals at a concentration of 200 mg L−1 inhibited the fermentation process the most. The hydrogen yield decreased in 7.2 and 3.6 times to 11.9 ± 2.1 and 23.8 ± 5.6 L kg−1 VSpotato in the presence of 200 mg L−1 Cu(II) and Cr(VI), respectively. The efficiencies of the chromium bioremoval in all variants of the experiment were 100%, and those of copper bioremoval were about 90%. A pure culture of strict anaerobes Clostridium butyricum strain 92 was used for the first time for the detoxification of metals. The presented results confirmed the possibility of this promising strain application for industrial H2 production and the bioremediation of contaminated sites.

We have investigated the influence of non-traditional raw materials of plant origin and natural additives on the formation of consumer properties of cupcakes with improved composition. We have defined and scientifically substantiated the formulation composition, as well as proposed model samples of cupcakes, based on the performed analysis of the organoleptic, physical-chemical indicators, food and biological value. Assessment of the organoleptic indicators was carried out based on the developed estimation scale considering such indicators as taste, smell, view at fracture, color, surface, shape, consistency following the introduction of the indicator for flavor; profilograms for samples were constructed. Based on the performed organoleptic assessment, it was established that the devised cupcakes, with the introduction of alternative raw materials to the formulation, have a good taste, flavor; they were highly appreciated by a tasting board. Due to a change to the formulation, it has become possible to reduce the caloric value of products by 16‒39 kcal/100 g. The new samples are characterized by a higher content of protein, by 18.9‒31.8 % (cupcakes without filling) and by 1.6‒1.7 times (cupcakes with filling), by a lower amount of fat, by 3.1–20.1 %, and carbohydrates ‒ by 4.7‒14.9 %. The content of essential amino acids was determined using the automated amino acid analyzer T 339. The new products demonstrated an increase in the content of amino acids, by 1.1‒1.9 times compared to control sample. The fat-acid composition of cupcakes was determined by gas chromatography applying the gas chromatographer HP 6890. The ratio of proportion of unsaturated fatty acids to saturated acids in new products increased by 1.22‒1.55 times. Mineral composition was determined by the method of atomic absorption spectrophotometry at the atomic-absorbing spectrophotometer C-115 PK. The content of mineral elements increased by 1.1‒2.7 times, of vitamins ‒ by 1.2‒2.9 times. Based on the acquired data we have justified the feasibility of extending the range of flour-based pastry products with the new types of cupcakes., Исследовано влияние нетрадиционного сырья растительного происхождения и натуральных добавок на формирование потребительских свойств кексов улучшенного состава. Определен и научно обоснованн рецептурный состав и предложены модельные образцы кексов на основе проведенного анализа органолептических, физико-химических показателей, пищевой и биологической ценности. Для оценки органолептических показателей разработана шкала оценивания, учитывая показатели: вкус, запах, вид в разломе, цвет, поверхность, форма, консистенция с введением показателя флейвор и построено профилограммы образцов. На основе проведенной органолептической оценки установлено, что разработанные кексы с внесением в рецептуру нетрадиционного сырья обладают приятными вкусом, ароматом и высоко оценены дегустационной комиссией. Благодаря изменению рецептуры удалось снизить энергетическую ценность изделий на 16–39 ккал/100 г. Новые образцы характеризуются повышенным содержанием белка на 18,9–31,8 % (кексы без начинки) и в 1,6–1,7 раз (кексы с начинкой), уменьшением количества жира на 3,1–20,1 % и углеводов - на 4,7–14,9 %. Содержание незаменимых аминокислот определяли с помощью автоматического анализатора аминокислот Т 339. В новых изделиях вырос содержание аминокислот в 1,1–1,9 раз по сравнению с контрольным образцом. Жирнокислотный состав кексов определяли методом газовой хроматографии на газовом хроматографе НР 6890. Соотношение доли ненасыщенных жирных кислот к насыщенным в новых изделиях возросло в 1,22–1,55 раз. Минеральный состав определяли методом атомно-абсорбционной спектрофотометрии на атомно-абсорбционном спектрофотометре С-115 ПК. Содержание минеральных элементов вырос в 1,1–2,7 раза, а витаминов в 1,2–2,9 раза. На основе полученных данных обоснована целесообразность расширения ассортимента мучных кондитерских изделий новыми видами кексов, Досліджено вплив нетрадиційної сировини рослинного походження та натуральних добавок на формування споживних властивостей кексів поліпшеного складу. Визначено та науково обґрунтовано рецептурний склад і запропоновано модельні зразки кексів на основі проведеного аналізу органолептичних, фізико-хімічних показників, харчової і біологічної цінності. Для оцінювання органолептичних показників розроблено шкалу оцінювання, враховуючи показники: смак, запах, вид у розломі, колір, поверхня, форма, консистенція із введенням показника флейвор та побудовано профілограми зразків. На основі проведеної органолептичної оцінки встановлено, що розроблені кекси із внесенням у рецептуру нетрадиційної сировини володіють приємними смаком, ароматом та високо оцінені дегустаційною комісією. Завдяки зміні рецептури вдалося знизити енергетичну цінність виробів на 16–39 ккал/100 г. Нові зразки характеризуються підвищеним вмістом білка на 18,9–31,8 % (кекси без начинки) та в 1,6–1,7 разів (кекси з начинкою), зменшенням кількості жиру на 3,1–20,1 % та вуглеводів – на 4,7–14,9 %. Вміст незамінних амінокислот визначали за допомогою автоматичного аналізатора амінокислот Т 339. У нових виробах зріс вміст амінокислот в 1,1–1,9 разів порівняно із контрольним зразком. Жирнокислотний склад кексів визначали методом газової хроматографії на газовому хроматографі НР 6890. Співвідношення частки ненасичених жирних кислот до насичених в нових виробах зросло в 1,22–1,55 разів. Мінеральний склад визначали методом атомно-абсорбційної спектрофотометрії на атомно-абсорбційному спектрофотометрі С-115 ПК. Вміст мінеральних елементів зріс в 1,1–2,7 раза, а вітамінів у 1,2–2,9 раза. На основі отриманих даних обґрунтована доцільність розширення асортименту борошняних кондитерських виробів новими видами кексів

Here, we have examined the nanoporous activated carbon fibers (ACFs) sulfonated using the direct sulfonation and the staged method that included bromination, followed by sulfidation and oxidation. TEM confirmed the nanoporous structure of the prepared sulfonated ACFs. Nitrogen porometry and 2D nonlocal DFT simulations showed the nanoporosity reduction and variations of the pore size distribution because of the functionalization. Comparison of parameters of the SO3H groups confined in nanopores, e.g., the thermal stability and catalytic potential, showed that the most efficient acid sites, in the catalytic 2-propanol dehydration to propylene, are the SO3H groups grafted by the staged Houben–Weil methods. From the productivity of reactions used at the preparation stage, and in contrast to the one-staged aromatic substitution, the bromine addition to π sites of the edges of carbon matrix supplies enough active sites and is a reason for further high yields of the grafted thermostable SO3H groups. Hydrolysis of the grafted bromine and the surface oxidation of nanopores walls are parallel reactions that lowered the SO3H-related acidity, increasing the total acidity to 1.5 mmol g−1. The reported nanoporous sulfonated ACFs are effective to be used in the dehydration reactions catalyzed by solid acids.

In this study, we report the green synthesis of gold nanoparticles (AuNPs) with the use of easily available, safe to handle juniper extract (Juniperus communis L.) as a reducing and stabilizer agent. The AuNPs were characterized by UV–Vis absorption spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM). Their growth was examined by UV–Vis spectroscopy over 24 h during storage at room temperature. Absorption measurements showed that the plasmon resonance wavelength appears around 530 and 700 nm. Electron-dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) of AuNPs evidenced the presence of Au (fcc) phases. TEM analysis showed spherical AuNPs and gold triangular nanoprisms. Differences in size and shape of the AuNPs were observed. ATR–FTIR confirmed the typical functional groups of polyphenols and their oxidation products on the AuNPs’ surface.

International audience; A novel sensing system was designed for pH measurements based on the enhanced and quenched photoluminescence (PL) and UV–Vis absorption of the diluted water solutions of F-, O-, and N-containing carbon nanoparticles (FON-CNPs). These FON-CNPs were solvothermally synthesized, dissolved, ultra-filtrated, and separated by thin-layer chromatography. The total fluorine content in them was found to be 1.2–1.5 mmol per gram. Their TGA showed a total weight loss of 52.7% because of the thermal decomposition and detachment of the surface groups and the partial burning of the functionalized shell on the carbon core at temperatures below 1200 °C. TEM and Raman data confirmed the presence of graphitic structures in the carbon core. From the results of ATR FTIR and UV–Vis spectroscopies, we showed that a carbon shell incorporates different functional groups covering the carbon core. The surface groups of the carbon shell include carboxyl, phenolic, and carbonyl groups. Heterocyclic N-containing and amino groups and trifluoromethyl groups supporting the hydrophobicity were also found. We suggested the possible reasons for the pH responses obtained with the sensing system considering them dependent on the de-protonation of functional groups with pH change.

Results of faunistic research of eight selected dipteran families (Bibionidae, Blephariceridae, Dixidae, Limoniidae, Pediciidae, Platypezidae, Ptychopteridae, and Rhagionidae) in the Uzh River Basin (Ukraine) are presented thanks to the support by the FAN (B) - Förderkreis für allgemeine Naturkunde (Biologie) in the framework of the project “Ephemeroptera, Plecoptera, Diptera biodiversity trip along the Uzh river, Ukraine”. Altogether 16 species are recorded as new to the fauna of Ukraine in the present paper. One species is newly recorded of the families Blephariceridae, Pediciidae, and Ptychopteridae, and two species each of the families Limoniidae and Bibionidae. Three species each belong to the families Dixidae, Platypezidae, and Rhagionidae.

Adsorption is currently the most promising capture technology to shorten atmospheric emissions of carbon dioxide (CO2). In this article, we report on the adsorption of CO2 onto pristine, oxidized, and aminated activated carbon (AC) sorbents. From our findings, some functionalized AC sorbents have shown very promising results in the CO2 capture process. Their maximum adsorption capacity measured by the thermogravimetric method at 20 °C varies between 2.2 and 3.9 mmol CO2/g depending on the content of diethylamino and oxygen-containing groups. The functionalization of the carbon surface with diethylamino groups improves the adsorption capacity by 30–40%. The CO2 adsorption little depends on the texture parameters of the pristine AC sorbents. In the range from 20 to 100 °C, the CO2 thermodesorption showed the effective regeneration of the sorbents. The aminated carbon surface demonstrates the best CO2 adsorption but binds the adsorbed molecules stronger than the oxidized surface, which limits the sorbent regeneration.

The aim of research is studying the effect of unconventional raw materials (buckwheat, oatmeal, rye, corn, milk whey, skimmed milk powder, propolis, flower pollen, bean powder, sesame oil, pumpkin seed oil, walnut oil, walnut kernels, candied fruit mixes (apple-cherry fruits of bilberries, natural honey with floral pollen, natural honey with propolis) for the quality and safety of new muffins. The article analyzes the results of the study of the quality and safety indicators of muffins of improved composition, manufactured using non-traditional raw materials. For the preparation of new types of muffins, part of the wheat flour was replaced with buckwheat, corn, oat, milk whey, skimmed milk powder and additives of vegetable origin. Margarine has been replaced by vegetable oils. It has been established that flour confectionery products have high organoleptic properties. From the physico-chemical parameters, the mass fraction of total sugar was determined, which ranged from 28.17 % to 33.07 %, the mass fraction of fat – 16.2–20.66 %, the mass fraction of moisture – 18.0–22.0, mass fraction of ash – 0.03–1.3 %, alkalinity – 0.03–1.8°, the content of toxic elements (copper, zinc, lead, cadmium, arsenic, mercury) and microbiological indicators were also determined. Based on the data obtained as a research result, the expediency of using non-traditional raw materials to expand the range of flour confectionery products, in particular muffins is substantiated.

The present study is dedicated to development of improved method for determination of trace amounts of fluorides in natural waters which is based on the interaction of fluorides with ion associate (IA) of Al(III), salicylic aldehyde acylhydrazones (benzhydrazone (SABH) and 4-picolinhydrazone (SAPH)) and polymethine dye Astra Phloxine FF (AP). Comparison of analytical forms [Al(SABH)2]⋅AP and [Al(SAPH)2]⋅AP showed that the analytical system Al(III)-SAPH-AP is more effective, namely, a higher level of preconcentration of the analytical form is ensured by and extraction equilibrium is achieved faster. Based on the study, we propose a new, fast, simple, reliable, sensitive, and accurate method of the indirect UV–Vis-spectrophotometric determination of fluorides grounded on the interaction of fluorides with IA of Al(III), SAPH and AP with the utilization of vortex-assisted liquid-liquid microextraction (VALLME). The method is based on the discoloration of the microextract of IA of Al(III), SAPH and AP (Al-SAPH-AP) in presence of fluoride ions due to the formation of fluoride complexes of aluminum with higher stability. The effect of various factors has been studied. The optimal conditions of the UV–Vis-spectrophotometric determination of fluorides were defined as: pH 7.0–10.0, 1.0⋅10−6 mol⋅L−1 Al(III); 4.0⋅10−5 mol⋅L−1 SAPH; 1.0⋅10−6 mol⋅L−1 AP; λ = 560 nm. VALLME have been carried out in 250 μL of CCl4 at 20:1 vol ratios of aqueous and organic phases, with vortexing at 3000 rpm for 15 s followed by centrifugation at 2000 rpm for 2 min. The determination of fluorides is feasible in the presence of various interferences. The calibration curve shows the linear dependence in the range of 0.3–114 μg⋅L−1 of the fluorides concentration (R2 = 0.993) with the limit of detection of 0.086 μg⋅L−1 and the limit of determination of 0.284 μg⋅L−1. The accuracy of the proposed protocol of fluorides determination was verified towards a reference method on the samples of natural rivers waters (RSD 2.6–3.1%, recovery 98.3–101.4%).

A few different theoretical methods for assigning the partial atomic charges were benchmarked for calculation of the hydrophilic/lipophilic index (HLI). The coefficients were selected to produce the best correlation of the HLI values with the experimental octanol-water partition. Different parameters were checked in calculations of partial charges to get the best performance of the HLI values obtained. Thus, four partitioning schemes (Coulson, Mulliken, Merz-Kollman, Ford-Wang) were benchmarked for calculations of atomic charges with six semiempirical methods (AM1, PM3, RM1, PM6, PM6-D3H4, PM7). Moreover, five distinct types of partial atomic charges (Mulliken, Hirshfeld, Löwdin, CHELPG, NPA), obtained at the Hartree-Fock and DFT levels of theory with three basis sets, were tested for their ability to produce the HLI values with the best correlation to experimental logP coefficients of 50 mono-charged organic anions. In the case of the semiempirical methods, the best correlation between the HLI and logP values (the correlation coefficient r = 0.9216) was obtained with the AM1 Ford-Wang parametric electrostatic potential charges. The Mulliken and Coulson charges calculated with the PM7 method can be used as an alternative to AM1, with the r values of 0.9107 and 0.8984, respectively. In the case of the DFT, the PBE/def2-TZVP natural population analysis charges produce the best correlation (r = 0.9220). Nevertheless, in spite of a marginally lower performance (r = 0.9159), the NPA charges computed at the PBE/def2-SVP level are more robust and can be regarded as the optimum choice for calculating the HLI values. Graphical abstract The hydrophilic/lipophilic index (HLI).

One of the major goals when creating new energy systems is to provide clean and affordable energy. Currently, there is an excessive increase in the cost of fossil fuels and natural gas because of increased energy consumption and the inability to meet demand. That is why it is necessary to find reliable renewable energy sources and processes that will produce energy materials without toxic by-products in order to preserve the environment and to ensuring sustainable development and a strong economy. From environmental safety reasons, this need has led to the development of the catalytic synthesis of energetic materials from greenhouse gases; in particular, this paper proposes an efficient approach to producing methane by hydrogenation of carbon dioxide over Co–Ni catalysts.

Large transition-metal contents add desirable physical properties, such as redox reactivity, magnetism, and electric or ionic conductivity to micas and make them interesting for a variety of materials-science applications. A Mn- and F-rich tainiolite mica, ${\rm{Cs}}\left( {{\rm{Mn}}_2^{2 + }{\rm{Li}}} \right){\rm{S}}{{\rm{i}}_4}{{\rm{O}}_{10}}{{\rm{F}}_2}$ , was synthesized by a high-temperature melt-synthesis technique. Subsequent annealing for 10 days led to a single-phase and coarsegrained material. Single-crystal X-ray diffraction studies were performed and characteristic geometric parameters were compared to the analogous ferrous compound, synthetic Fe-rich tainiolite, ${\rm{Cs}}\left( {{\rm{Fe}}_2^{2 + }{\rm{Li}}} \right){\rm{S}}{{\rm{i}}_4}{{\rm{O}}_{10}}{{\rm{F}}_2}$ . Both tainiolite structures are outside the compositional stability limits for the 2:1 layer structure, and incorporating the relatively large cation Mn2+ requires significant structural adjustments in both the octahedral and tetrahedral sheets. As expected, increasing the ionic radius of the octahedral cation from 0.78 A (VIFe2+) to 0.83 A (VIMn2+) reduces the octahedral flattening angle from = 57.05° to = 56.4°, the smallest value ever observed for a tetrasilicic mica. However, even this small value is insufficient to match the lateral sizes of the tetrahedral and octahedral sheets and, in addition, unusual structural adjustments in the tetrahedral sheet are required. The average tetrahedral bond length is much greater (1.643 A) than the average value observed for tetrasilicic micas (1.607 A,) and a significant difference between the apical (1.605 A) and the basal bond lengths (1.656 A) and an enlarged basal flattening angle (τbasal = 106.29°) are noted. These parameters indicate: (1) that the 2:1 layer might be more flexible than previously thought, to allow matching of the lateral dimensions of the tetrahedral and octahedral sheets; and (2) that many other compositions that appear interesting from a materials-science point of view might be accessible.