Abstract Results are presented from investigating active and drainage layers of composite films (membranes) UPM-50 and UPM-100 before and after exposure to transmembrane pressure by means of IR spectra of reflection, X-ray scattering, and raster electron microscopy. It is found that changes in the IR spectrum of the working sample are caused by the destruction of weak bonds of C=O···H–N amide fragments

Abstract Thermogravimetric analysis (TGA) is used to study the thermophysical properties of three ionic liquids with 1-butyl-3-methylimidazolium cation. The temperatures and enthalpies of melting and thermal decomposition are determined, and the IR spectra of gaseous products of thermal decomposition are studied. The relationship between the structure of compounds and their thermochemical characteristics

Abstract The process of gas hydrate film growth along the water–gas interface is analyzed. It is assumed that the driving force of this process is the concentration driving force. The available experimental data on the kinetics of the process under consideration are compared to calculated data obtained in the framework of the theoretical model proposed earlier. The dependence of the thickness of the

Abstract The vapor conversion of methane on Ni-containing catalysts on structured metal supports made from a Fe–Cr–Al alloy (fechral) is studied. A very high hydrogen content is observed in the products of the reaction for low percent 1% Ni/fechral catalysts (around 75% at 870°C).

Abstract The energy of combustion of crystalline triphenylantimony dibenzoate is measured using an isoperibolic combustion calorimeter with a static bomb at T = 298.15 K. The experimental data show that the standard enthalpy of combustion of this substance in the crystalline state is calculated for T = 298.15 K. Standard functions ∆fH° and ∆fG° of the formation of the compound in the crystalline state

Abstract Potentiometry is used to determine the stepwise dissociation constants of glycyl-L-aspartic acid at 298.15 K and ionic strengths of 0.1, 0.3, 0.5. 1.0, 1.5 (KNO3). The obtained data are extrapolated to zero ionic strength according to an equation with one individual parameter, and the values of the thermodynamic dissociation constants are calculated.

Abstract Polarimetry is used to study the optical activity of colloidal aqueous solutions of nonionic surfactant (NS) Triton X-100. It is found that these solutions rotate the plane of polarization to the right. It is shown that a change in the concentration of nonionic surfactants alters the structure of micelles. It is found that the transition to a continuous hexagonal mesophase is accompanied by

Abstract The problem of the unit slope of the Brønsted plot for the proton transfer reaction from the “hard” CH-acids is considered by the example of a series of gas-phase deprotonation reactions of substituted benzenes with the CH2CN– anion. The discussion is conducted within the framework of the theory of non-equilibrium reactions. The use of intramolecular reorganization (IMR) method allows calculate

Abstract Samples of pine wood ozonated with different contents of water are studied via UV diffuse reflectance spectroscopy. It is shown that polyaromatic and stilbene structures, guaiacyl derivatives, and carbonyl- and carboxyl-containing aromatic structures of lignin are destroyed during ozonation of pine wood. The destruction of aromatic structures proceeds efficiently in wood with a moisture content

Abstract This study was conducted to synthesize copper(II) oxides (CuO) with dendrite, leaf and feather morphologies. Synthesized CuO with dendrite and leaf morphologies were characterized by XRD, SEM, and BET/BJH and CuO with feather morphology with XRD, SEM, BET/BJH, FTIR, TEM, and DRS techniques. The effect of various CuO morphologies on Zn(II) adsorption was investigated. Among the morphologies

Abstract Optical infrared gas analyzers are developed for mixtures of vapors of liquefied natural gas and air. It is found that a network of them allows temperatures of −100 to +60°C to be measured along with volume concentrations of hydrocarbons С = 0.5–100 vol % with temporal responses of less than 1–2 s when analyzing methane–air emissions and clouds in the atmosphere with volumes of up to 107 m3

Abstract The state of tetra(1,2,5-selenodiazolo)porphyrazine in proton-acceptor media of different basicities is studied. It is shown that porphyrazine with selenodiazole rings forms a proton-stable complex with proton transfer in dimethylsulfoxide. Addition of nitrogen-containing bases into dimethylsulfoxide destabilizes this complex, with subsequent destruction of the porphyrazine macrocycle. It

Abstract The aggregation behavior of mixed micellar solutions of cationic hexadecylpiperidinium surfactants and nonionic surfactant Tween 80 is studied. The critical micelle concentration is determined by varying the component ratios, and a negative deviation from the ideal mixing model can be observed (synergistic effect). The adsorption parameters and surface potential of mixed micelles are estimated

Abstract The conversion of methane, ethylene and mixtures of them in aqueous solutions was studied using ultrasonic vibrations with a frequency of 22 kHz under conditions of cavitation. It is found that formaldehyde, the main product, forms even if there is no dissolved oxygen in the initial solution. It is shown that the rate of accumulation of formaldehyde depends on the power of the ultrasound and

Abstract A unified description of three types of two-phase interfaces (vapor–liquid, solid–vapor, and solid–liquid) at a vapor–liquid meniscus inside a slit-like pore are considered on the basis of the lattice gas model. This approach allows equally accurate calculations of molecular distributions in heterogeneous distributed models of transitional regions at all interfaces. It is assumed that pore

Abstract The effect partially replacing neodymium with barium or strontium has on the thermal behavior of Nd0.85A0.15MnO3 (A = Ba, Sr) manganites is investigated. The temperature aspects of the transformation of their crystalline structure under different pressures of an oxygen atmosphere are studied. The sequence of phase transformations during the thermal dissociation of the compounds under reduced

Abstract Au–Pd NPs@CNSs/GO nanocomposites have been fabricated by the in situ growth of Au–Pd nanoparticles on carbon nanospheres (CNSs) using ascorbic acid as reducing agent and diethylenetriamine (DETA) as a coupling linker and the subsequent assembly of the Au–Pd NPs@CNSs on graphene oxide (GO). In the nanocomposites, the Au–Pd NPs alloys have an average particle diameter of less than 10 nm. The

Abstract A set of rheological experiments is performed for interphase adsorption layers at a water/butyl methacrylate interface formed by high molecular weight surfactants (HMWSs) (polyvinyl alcohol with various acetylated groups (PVA) and copolymer 2-acrylamido-2-methylpropanesulfonic acid with methyl methacrylate (AMPSA-MMA) having different contents of MMA links). It is shown there is an increase

Abstract Electron spectroscopy shows that the protonation of ferrocenylcrboxylic and ferrocenylacetic acids is accompanied by the redox isomery of generated ferrocenecarbenium ions. The effect the nature of the metal complexes, Brønsted acids, and solvents has on the rate of redox isomery is determined. It is shown kinetically that the stabilization of the acylium ion FcC+O (where Fc is ferrocenyl)

Abstract General patterns of ozone pretreatment for subsequent fermentation into sugars are found, based on samples of different types of plant biomass. It is shown that the reactivity of plant substrates pretreated with ozone is determined by the amount of consumed ozone, and the rate of ozone consumption depends on the content of water in a sample. Optimum values of moisture (~2FSP) and ozone consumption

Abstract The structure–activity relationship of ten mercaptoalcohol molecules as corrosion inhibitors for carbon steel was investigated through quantum chemistry calculation and molecular dynamics simulation (MD). Quantum chemical parameters including the energy of the highest occupied molecular orbital (EHOMO) and the lowest unoccupied molecular orbital (ELUMO), energy gap (ΔE), electronegativity

AbstractAn approach is formulated that allows calculation of three types of surface and linear tensions in the region of contact angles of a three-aggregate system. A molecular theory for three-aggregate systems based on the lattice gas model (LGM) is used to calculate surface tension (ST) and linear tension (LT). It provides a uniform description of molecular distributions of mixture components inside

AbstractPartial and integral thermodynamic functions of the mixing and evaporation of nickel–calcium melts are calculated from the values of calcium vapor pressure at 900–1300°C (1173–1573 K), determined using the boiling points approach (isothermal version), and those of nickel, found via numerical integration of the Gibbs–Duhem equation. It is established that the formation of alloys containing up

AbstractThe dynamics of wheat straw delignification with ozone treatment is studied. The dependence of the residual lignin content on the specific absorption of ozone is determined. It is found that in a prolonged stage of ozonation, ozone is consumed mostly for the reaction with lignin. HPLC is used to record kinetic profiles of water-soluble products of ozonation. The IR spectra of straw samples

AbstractThe thermal effects of the reactions of Co(II) complex formation with triglycine in aqueous solution at a temperature of 298.15 K and ionic strengths of 0.2, 0.5, and 1.0 (KNO3) were determined by direct calorimetry. The standard thermodynamic characteristics (ΔrH°, ΔrG°, ΔrS°) of complexation reactions in the system were calculated.

AbstractProcesses of complexation in the Fe(0)–Fe(II)–glycine–Na(H)ClO4–H2O system at a temperature of 298.15 K, an ionic strength of solutions of 0.1–1.0 (NaClO4), СFe(II) = 1 × 10−3, and in the pH range of 0.8–8.0 are studied according to the Clark–Nikolsky oxidation potential. Experimental curves are obtained for the dependences of EMF on concentration, рН, pCFe(II), рСHL. Successive approximation

AbstractDensities and viscosities of binary mixtures of diisopropyl ether (DIPE) with methyl benzoate (MB), ethyl benzoate (EB) and benzyl acetate (BA) were measured experimentally at T = (298.15, 303.15, 308.15, and 313.15) K and P = 0.1 MPa for the entire composition range. The estimated values of the pure liquids and mixtures were subsequently used to determine the properties such as excess molar

AbstractThis study has focused on the applications of newly prepared zinc oxide (ZnO) composite with polyvinylpyrrolidone (PVP) for adsorptive removal of methyl orange and Congo red dyes. The performance of ZnO–PVP composite in removing the dyes from aqueous solution is almost double than the simple metal oxide, which signifies the role of PVP in the composite of metal oxide–PVP. The adsorption of

AbstractAn approach is developed that allows estimation of excited quadrupole molecule parameters responsible for changes in vibration frequencies in states with symmetry breaking by charge transfer from time-resolved IR spectra. The approach is tested on a molecule like A-π-D-π-A composed of an electron-accepting group A coupled with electron-donating group D by means of π-conjugated bonds, a D pyrrolopyrrole

AbstractAn extended benchmark study has been performed to find out a robust and accurate density functional for calculating the standard reduction potentials of vanadium compounds. Twenty eight density functionals of various types were chosen for testing. The effect of the functional nature, size of the basis set, and inclusion of dispersion interaction in the calculation on the accuracy of the results

AbstractA theoretical study is made of the piezoresistive properties of chiral carbon nanotubes with different types of conduction, both ideal and doped with substitutional point defects at different concentrations, uniformly distributed in the crystal lattice. Boron and nitrogen atoms are chosen as acceptor and donor impurities, respectively. The energy-band structure of the studied nanoparticles

AbstractThe adsorption behavior of atenolol molecule over the pristine carbon nanotube and boron nitride nanotube as well as functionalized carbon nanotube was performed employing the B3LYP and CAM-B3LYP methods with 6-311G(d, p) basis set in two phases (gas and water solution). We used natural bond orbital, non-covalent interactions and the quantum theory of atoms in molecules to investigate the hydrogen

AbstractData on the spectroscopy of photoexcitation of trans-to-cis isomerization and fragmentation of protonated trans-azobenzene (ABH+) in an inert gas atmosphere are analyzed. Results from gas-phase isomerization are compared to ones from a liquid-phase reaction in aqueous sulfuric acid that results in the formation of cyclic benzo[c]cinnoline. There is no cyclization upon gas-phase trans-to-cis

AbstractDynamic expressions for bulk and shear viscosity coefficients are obtained on the basis of statistical theory and a model of a two-component system. The dependence of the coefficients of shear viscosity of magnetic fluids based on water, kerosene, and undecane on the frequency and magnitude of an external magnetic field is calculated from the selection of potential energies for intermolecular

AbstractThe steam conversion of glycerol is studied on Ni-containing oxide and carbon-supported catalysts. For low-percent catalysts—0.88% Ni/C and especially 1.6% Ni/C, very high contents of CO are detected in the products of reaction, reaching around 35–36% at 720°C.

AbstractThe possibility of predicting the effectiveness of wetting agents to increase the oleophilicity of surfaces of copper phthalocyanine is considered. The proposed way of predicting is based on calculating certain reactivity descriptors (charges on atoms, energy and localization of boundary orbitals, molecular electrostatic potential, absolute hardness (according to Pearson), and the index of

AbstractA theoretical and experimental study is performed for liquid–solid phase equilibria in the two-component diphenyl oxide–n-hexadecane system. The results show that this system is eutectic. Two means are chosen for the theoretical study of the system: the Schröder–Le Chatelier equations and the original UNIFAC system. Experimental studies are made via differential thermal analysis on a DSC unit

AbstractQuantum chemistry calculations were performed using density functional theory (DFT) to evaluate electronic and sensing properties in the presence and absence of gas molecules HF and H2O of pristine and dope carbon nanotubes (CNTs) zigzag (6, 0), and CNTs doped with gallium and zinc, which have a significant effect on improving the sensing properties. The results appear that the gas molecules

AbstractReactions of photochemical hydrogen transfer are modeled by means of quantum chemistry. Nitromethane and nitrobenzene in the triplet state in combination with ammonia, methylamine, or dimethylamine as hydrogen donors are studied. The structures of reaction complexes of the original materials, the transitional states and reaction products, the activation energies of the reactions, and changes

AbstractIn the present work, the adsorption configurations, electronic states and magnetism of Fe-Pc on Au(111) are investigated using first-principles calculations. We showed that the most favored configuration is the top site using the generalized gradient approximation method SGGA, whereas, it is the hcp position with the SGGA + U approach (in the presence of the Hubbard term U). An interesting

AbstractMacropores were prepared by electrochemical etching on p-type silicon. The effects of resistivity, etching time and HF concentration on the porosities and morphologies of macropores were investigated. It was found that the porosity of p-type macropores increased exponentially at the beginning with the increase of etching time under any other etching parameters. In addition, we discovered that

AbstractJ. Li’s simple model for calculating the percolation threshold in polymer nanocomposites is analyzed. It is shown that it can be used, but with considerable amendments. First, a solution must consider problems of nodes on a cubic lattice; second, it is better to average the orientation of anisodiametric nanoparticles.

AbstractIsoperibolic calorimetry is used to determine the enthalpies of mixing of liquid alloys of the Ag‒Al–Yb system along two radial sections with a constant ratio of atomic fractions of aluminum and silver: (1) xAg/xAl = 0.46/0.54 at 1271 ± 1 K and (2) xAg/xAl = 0.19/0.81 for 1454 ± 5 K up to xYb ∼ 0.2. It is found that melts of the studied system form with the release of a small amount of heat

AbstractThe acidity constants of a number of guaiacyl phenols simulating structural fragments of natural lignins in the electronically excited state in water–N,N-dimethylformamide mixtures are determined by fluorescence spectroscopy using the Förster cycle. The differentiating effect of an aprotic solvent on the acidity of phenols is shown. It is found that the pKa values in the excited state are associated

AbstractThe continuum quasichemical approximation is used to improve the accuracy of describing molecular distributions in a vapor–liquid system. It considers displacements of the molecular center of mass from the center of a cell within the lattice gas model. It also allows for (as in its discrete variant) direct correlations of interacting molecules. The probability density of a molecule being inside

AbstractHybrid nanosystems based on nanoparticles of zero-valent copper (Cu0), zero-valent silver (Ag0), and zero-valent selenium (Se0) are synthesized. The nanoparticles are stabilized by a water-soluble random copolymer of 2-deoxy-2-methacrylamido-D-glucose with 2-dimethylaminoethyl methacrylate. A comparative study is made using UV–Vis spectroscopy and atomic force microscopy. The effect the nature

AbstractA study is made of the effect incorporating 1,3-diketones (acetylacetone, benzoylacetone, dibenzoylmethane, and benzoyltrifluoroacetone) into the coordination sphere of gadolinium stearate has on the frequency, magnetic, and dielectric properties of heteroligand complexes. The compositions of synthesized heteroligand complexes of gadolinium stearate with 1,3-diketones are determined via thermogravimetric

AbstractA new interpretation of the emission properties of carbon nanotubes is presented using the theory of electron conjugation. The presence of emission molecular states in the energy spectrum of carbon nanotubes, characterized by specific localization of electron density on the end surfaces of carbon nanotubes, is explained from the viewpoint of the concepts of in-plane and ρ-electron conjugation

AbstractDifferent redispersate solutions of a silver–sorbitan monooleate nanocomposite in n-heptane with silver concentration of 8 × 10−5–1 × 10−3 M are used to obtain thin double-sided silver films on glass and quartz substrates. Photon correlation spectroscopy is used to show that the size of particles in solutions varies in the range of 9–90 nm. The films are characterized via atomic absorption

AbstractThe electrodeposition of zinc–iron–cobalt alloys from sulfate bath was carried out galvanostatically on steel. A complementary approach based on of a combination of different electrochemical techniques was used to clarify the deposition mechanism. The electrodeposition of the alloys was of an anomalous type. The corrosion behavior of the coatings was evaluated from polarization measurements

AbstractThe solubilities in the quaternary system (LiCl + NaCl + KCl + H2O) at 288.15 K were investigated with the method of isothermal dissolution equilibrium. The phase diagram includes one cosaturated point, three isotherm dissolution curves, and three crystallization regions corresponding to sodium chloride, potassium chloride, and lithium chloride dihydrate. The area of the crystallization region

AbstractPolarization of lithium iron phosphate-graphite batteries greatly affects its quality and life. In order to reduce the electrode polarization, the multi-walled carbon nanotubes/graphite double-layer anode was proposed to improve the performance of the battery, and the depolarization of the graphite anode electrode interface was studied. For the study of depolarization the electrode materials

AbstractCondensed products are obtained via the partial oxidation of iron(II) cations using potassium permanganate, and their physicochemical properties are studied. Samples obtained at a potassium permanganate-to-iron(II) molar ratio close to stoichiometric in a preparation of magnetite have the greatest relative magnetic susceptibility. It is shown that the initial rate of formation of relative magnetic

AbstractThe results from assessing the salting-out capacity of inorganic salts with respect to poly(ethylene glycol) monoalkyl ethers (DS-10 and ALM-10 synthanols) are summarized. The effect the length of the aliphatic substituent in a molecule of a surfactant has on the salting-out capacity is determined. The correlation dependences between the energy of hydration of ions and their salting-out capacity

AbstractThe activities of oxides in CaO–TiO2 melts in the temperature region of 2241−2441 K are determined via Knudsen effusion mass spectrometry. Such thermodynamic properties of calcium titanate melts as the chemical potential of their oxides, their energies of mixing, and their partial and integral enthalpies and entropies of formation are calculated from the experimental data. The results are compared

AbstractIt is established that 82% of the vapor can condense into the liquid phase when calcium is evaporated from an alloy with copper at low pressures of 0.7–1.33 kPa under nonequilibrium conditions. Based on values of the vapor pressure of calcium and copper determined using the boiling point approach, a complete diagram of state is constructed that includes the condensed and vapor phases at atmospheric

AbstractProcesses of the multi-stage decomposition of maleic acid and Li, Na, and Cd maleates in an inert atmosphere are studied via thermal analysis with synchronous analysis of the composition of the released gases. Reaction mechanisms are proposed according to the data on the mass loss stages determined via thermal analysis, gaseous products, and the final solid decomposition products. It is shown

AbstractThe density (ρ) and viscosity (η) of the mixtures of 1,6-diaminohexane (DAH) + water binary system were determined over the whole composition range at p = 101 kPa from 293.15 to 333.15 K. The measured density and viscosity values decrease with the increase of temperature. In addition, the viscosity of the binary system shows a maximum value along with the molar fraction of DAH. According to

AbstractIn our previous work, we illustrated that tetrachroridoplatinum(IV) complex with dipyridylamine (PtIVdpa) exhibited to be a selective cytotoxic drug, among a series of similar analogues in the in vitro study. In this research, by means of the Becke3LYP DFT functional calculations, PtIVdpa was compared with a known platinum(IV) drug, tetraplatin (PtIVdach), theoretically. The mechanism of two-electron

AbstractMetal-organic framework (MOF) is a strong candidate for gas storage and gas separation, which can be modified by various functional groups. In this study, we performed Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations to investigate the effect of F, Cl, Br, CHO, NO2, ethyl (Et), methyl (Me), and SH functional groups on the methane and carbon dioxide adsorption and CH4/CO2