Concentration Of Active Centers Research Articles

Физико-химические трансформации сапонитсодержащего материала при его активации измельчением

Structural-phase transformations on the surface of powder systems of saponite-containing material after mechanical dispersion have been studied. The degree of crystallinity, adsorption capacity and specific surface energy depending on the time mode of grinding were used as compared information characteristics. It has been established that, despite the fact of the constancy of the degree of crystallinity, mechanical grinding of saponite-containing raw materials leads to its activation, which is expressed by a proportional increase in the sorption capacity of the obtained powders, an increase in the concentration of active adsorption centers and the value of the specific free surface energy. An increase in the time of mechanical grinding of a saponite-containing material leads to the production of samples with an increased (compared to the initial material) surface hydrophilicity.

Multilayer coatings based on gold nanoparticles and polymers with bovine serum albumin as a functional layer for the chiral separation in capillary electrochromatography.

In this study, we developed physically adsorbed multi-layer coatings using poly-l-lysine or poly(diallyldimethylammonium chloride) and gold nanoparticles, which were functionalized with bovine serum albumin for the chiral separation in electrochromatography. The approach involves sequentially depositing positively charged polymers and negatively charged citrate-stabilized gold nanoparticles. By repeating this modification cycle, we created two- and four-layer coatings, which were sequentially functionalized with albumin forming three- and five-layer coatings that were finally applied for the separation of enantiomers of dl-tryptophan. The formed coatings exhibit stability across a pH range of 2-10 and feature a dense, uniform surface, as confirmed by scanning electron microscope images. The number of layers impacted nanoparticle deposition density, with five-layer coatings being denser than three-layer ones. Five-layer coatings enable baseline separation of dl-tryptophan enantiomers, whereas three-layer coatings require the presence of albumin in the background electrolyte for separation. Therefore, increasing the number of layers and gold nanoparticles density enhances albumin active center concentration on capillary walls, improving the separation of dl-tryptophan enantiomers. The five-layer coatings can be easily fabricated and possess good repeatability of analytes migration time.

Luminescence in Anion-Deficient Hafnia Nanotubes.

Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronic devices. They possess a unique combination of physical and chemical properties, such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric HfO2 nanotubes. As-grown amorphous hafnia nanotubes and nanotubes annealed at 700 °C with a monoclinic crystal lattice served as samples. It has been shown that the bandgap Eg for direct allowed transitions amounts to 5.65 ± 0.05 eV for amorphous and 5.51 ± 0.05 eV for monoclinic nanotubes. For the first time, we have studied the features of intrinsic cathodoluminescence and photoluminescence in the obtained nanotubular HfO2 structures with an atomic deficiency in the anion sublattice at temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3-2.4 eV has been revealed. We have also conducted an analysis of the kinetic dependencies of the observed photoluminescence for synthesized HfO2 samples in the millisecond range at room temperature. It showed that there are several types of optically active capture and emission centers based on vacancy states in the O3f and O4f positions with different coordination numbers and a varied number of localized charge carriers (V0, V-, and V2-). The uncovered regularities can be used to optimize the functional characteristics of developed-surface luminescent media based on nanotubular and nanoporous modifications of hafnia.

Metal-organic framework boosts heterogeneous electron donor–acceptor catalysis

Metal-organic framework (MOF) is a class of porous materials providing an excellent platform for engineering heterogeneous catalysis. We herein report the design of MOF Zr-PZDB consisting of Zr6-clusters and PZDB (PZDB = 4,4’-(phenazine-5,10-diyl)dibenzoate) linkers, which served as the heterogeneous donor catalyst for enhanced electron donor–acceptor (EDA) photoactivation. The high local concentration of dihydrophenazine active centers in Zr-PZDB can promote the EDA interaction, therefore resulting in superior catalytic performance over homogeneous counterparts. The crowded environment of Zr-PZDB can protect the dihydrophenazine active center from being attacked by radical species. Zr-PZDB efficiently catalyzes the Minisci-type reaction of N-heterocycles with a series of C-H coupling partners, including ethers, alcohols, non-activated alkanes, amides, and aldehydes. Zr-PZDB also enables the coupling reaction of aryl sulfonium salts with heterocycles. The catalytic activity of Zr-PZDB extends to late-stage functionalization of bioactive and drug molecules, including Nikethamide, Admiral, and Myristyl Nicotinate. Systematical spectroscopy study and analysis support the EDA interaction between Zr-PZDB and pyridinium salt or aryl sulfonium salt, respectively. Photoactivation of the MOF-based EDA adduct triggers an intra-complex single electron transfer from donor to acceptor, giving open-shell radical species for cross-coupling reactions. This research represents the first example of MOF-enabled heterogeneous EDA photoactivation.

Effect of Phosphorus, Iron, Zinc, and Their Combined Deficiencies on Photosynthetic Characteristics of Rice (Oryza sativa L.) Seedlings

Combined elemental deficiencies are more complex and insidious physiological metabolic responses than single elemental stresses. To determine the effects of phosphorus (P), iron (Fe), zinc (Zn), and their deficient combinations on photosynthetic characteristics of rice seedlings, we investigated their effects on dry weight, chlorophyll (Chl) content, rapid photosynthetic carbon assimilation CO2 responses, and Chl fluorescence in four-week-old rice (CB9 and BJ1 cultivars) seedlings. The results showed that the dry matter, maximum carboxylation efficiency (Vc,max), and maximum electron transfer efficiency (Jmax) of seedlings were all reduced to different degrees under the element deficiency treatments. JIP-test analysis showed that the decrease in the concentration of active PSII reaction centers (RC/ABS) under -Zn treatment was the main reason for the inhibition of performance index PIABS. The -P treatment reduced RC/ABS and inhibited electron transfer (ψEo). Primary photochemical reactions (φPo) of -P-Zn treated seedlings were also inhibited compared to the -P treatment. The -Fe and -Fe-Zn treatments inhibited photosynthesis most severely, which not only reduced RC/ABS but also severely inhibited φPo and ψEo. Notably, the -P-Fe and -P-Fe-Zn treatments of the CB9 improved the RC/ABS, alleviating the limitation of Fe deficiency. These results help enhance the understanding of the complex relationship between nutrient balance and photosynthesis, especially for P, Fe, Zn, and their combined deficiency.

Acid-Base and Photocatalytic Properties of the CeO2-Ag Nanocomposites

In this work, CeO2 nanoparticles, as well as CeO2 nanocomposites with plasmonic silver nanoparticles, were synthesized using a simple sol-gel process. The concentration of silver in the composites varied from 0.031-0.25 wt%. Cerium hydroxide dried gel was calcined at temperatures from 125 to 800 °C to obtain CeO2. It was shown that, at an annealing temperature of 650 °C, single-phase CeO2 nanopowders with an average particle size in the range of 10-20 nm can be obtained. The study of acid-base properties showed that with an increase in the calcination temperature from 500 to 650 °C, the concentration of active centers with pKa 9.4 and 6.4 sharply increases. An analysis of the acid-base properties of CeO2-Ag nanocomposites showed that with an increase in the silver concentration, the concentration of centers with pKa 4.1 decreases, and the number of active centers with pKa 7.4 increases. In a model experiment on dye photodegradation, it was shown that the resulting CeO2 and CeO2-Ag nanopowders have photocatalytic activity. CeO2-Ag nanocomposites, regardless of the silver concentration, demonstrated better photocatalytic activity than pure nanosized CeO2.

Selective and green oxidation of alcohols and sulfides using mesostructured Cux/Cey mixed oxides

Mesostructured mixed metal oxides are one of the best candidates for various oxidations. Here, mesostructured Cux/Cey mixed oxides with various Cu/Ce ratios were prepared using mesoporous silica as a hard template to improve their selectivity and efficiency as the oxidative catalysts. Investigation of the different ratios of Cu/Ce showed that all catalysts are significantly more active than their salts in the oxidation of alcohols and sulfides with some green oxidants. The results demonstrated that the balance of the number of active catalytic centers (concentration of Cu) and the structural characteristics (surface area and oxygen vacancy) determine the activity of the catalysts. It also seems to be a powerful interplay among copper and cerium ions that helps the reduction of both Cu (II) and Ce (IV).

In English

Wastewater and natural waters contain various pollutants of both natural and artificial origin. Treatment of these waters is carried out comprehensively by various methods, which significantly increases costs. Currently, the problem of a large amount of drugs entering the wastewater is very relevant. Drugs, unchanged or in the form of metabolites, enter the wastewater together with the waste products of a living organism. To solve urgent practical problems of water purification, a possibility of using natural zeolite materials as sorbents has been recently considered. Being a natural aluminosilicates of frame-type structure, these minerals have a number of unique adsorption properties that can be used in water treatment processes. Treatment with acid solutions (alkalis, salt solutions and some organic compounds) allows to improve significantly their sorption characteristics for decision of a particular problem. Zeolites, being chemically stable minerals, are capable to withstand the effects of chemically active medium without destruction of the crystal lattice. The effect of boiling acid (HC1) on natural zeolites from Georgian deposits (mordenite and clinoptilolite) and the possibility of their use for adsorption treatment of wastewater were studied in this work. Identification of modified zeolites was carried out on the basis of X-ray diffractograms and IR-spectra. It has been shown that natural clinoptilolites (mordenite and zeolite) are characterized by high thermostability and acid resistance even after acid-modification, and the resulting hydrogen forms are distinguished by high concentration of active centers; the efficiency of adsorption method for wastewater treatment from some pharmacopolutants when using acid-modified natural zeolites has been also shown. This method will solve the problem of entering the environment of drugs with lower costs

Comprehensive activity analysis of silicacontaining raw materials for use in mechanical activation efficiency evaluations

The matrix formed predominantly at the hardening of binders through various physical and chemical mechanisms, with the consolidation of all material components into a single high-strength conglomerate, represents a key element in the structure of any composite, ensuring its basic quality. The use of mineral additives, represented mainly by silica-containing raw materials with high pozzolanic activity, as fillers or modifiers allows producing a consolidating binder that is required to obtain materials with the desired properties. Natural raw materials with a stable composition and consistent properties may be modified to increase their dispersion and activity. Mechanical activation in grinding machines is the most effective of all modification methods. The degree of variation in the properties of any substance mainly depends on the typomorphic parameters of the material being ground. Since the resulting mechanically activated substance is to be further used in mineral binder systems, its activity may be regarded as a key quality indicator for the respective ground raw materials. The purpose of this work was to conduct a comprehensive activity assessment for mineral components with various compositions and structures following their mechanical activation by various methods. The set of physical and mechanical properties analyzed included grain-size distribution, dispersion, sorption capacity, concentration of active centers, and surface energy. Common raw materials, such as sand, granite, opoka rock, and perlite, were studied. The dependence is shown between the degree of mechanicalactivation of a substance and its resulting physical and mechanical properties. The following efficiency rating may be compiled for the grinding types based on the activity generated: wet grinding → dry grinding → grinding to obtain a mineral suspension.The study was carried out under the grant issued by the Russian Science Foundation (project No. 19-19-00263) using the equipment of the Center for High Technologies of the Belgorod State Technological University named after V. G. Shukhov.

Effect of alkylaluminum structure and aggregation state on the micro-kinetics of ethylene polymerization catalyzed by α-diimine nickel complex

2-thiophenecarbonyl chloride (TPCC) quenching method was used into the study of alkylaluminum activation behavior on α-diimine nickel catalysts. The influence of alkylaluminum structure (AlEt2Cl, Al2Et3Cl3, AlEtCl2 and modified methylaluminoxane (MMAO)) and polymerization temperature on the kinetic factors (active center concentration [C*] and chain propagation rate constant kp) of ethylene polymerization catalyzed by the system was systematically studied. It was found that, compared with MMAO, alkyl aluminum chloride could better activate catalyst and produced more active centers in the polymerization system, but the value of kp was lower than MMAO. Unexpectedly, as the polymerization temperature increased, [C*] in the polymerization system with AlEtCl2 as cocatalyst gradually increased, and kp decreased. But the change of [C*] and kp of the polymerization system with MMAO as cocatalyst was opposite. It was proposed that cocatalyst is one of the factors affecting the thermal stability of catalyst.

Facile One-Step Flame Synthesis of La1−xSrxMnO3 Nanoparticles for CO Catalytic Oxidation

A large amount of CO as hazardous emission in the iron ore sintering process has caused severe harm to the environment and human health. To control the emission of CO more effectively, the preparation of highly efficient catalysts has attracted much attention. In this study, the La1-xSrxMnO3 (0 ≤ x < 1) perovskite catalysts with different Sr2+ contents were prepared by the one-step flame synthesis method to treat CO pollutants in the iron and steel industry. The influence of Sr2+ doping on the structure and activity of catalytic were characterized and analyzed. La1-xSrxMnO3 perovskite catalysts exhibit good perovskite phases and loose spherical structures. The specific surface areas are between 4.1 and 12.0 m2 g−1. Combined with the results of H2-TPR and O2-TPD, the improvement of catalytic activity of La1-xSrxMnO3 perovskite can be attributed to the high concentration of active centers and oxygen vacancies. Significantly, the La0.4Sr0.6MnO3 catalyst presented the best reducibility and high content of absorbed active oxygen species, leading to a superior CO oxidation catalytic activity and reaches 50% CO conversion at 134.9°C and 90% at 163.2°C, respectively. The effects of water vapor and CO2 on the oxidation activity of La1-xSrxMnO3 perovskite was investigated. The flame-produced catalysts exhibit favorable catalytic stability and antisintering ability, achieving 100% CO conversion after fifth consecutive oxidation cycles.

Ni–Ru-containing mixed oxide-based composites as precursors for ethanol steam reforming catalysts: Effect of the synthesis methods on the structural and catalytic properties

Abstract Ethanol steam reforming catalyst’s precursors, i.e., nanocomposites of complex oxides with the general formula [Pr0.15Sm0.15Ce0.35Zr0.35O2 + LaMn0.45Ni0.45Ru0.1O3] (1:1 by mass), were synthesized by three different methods. It was shown that two synthesis methods – ultrasonic dispersion and sequential polymeric method, lead to the formation of the nanocomposite perovskite–fluorite system with the specific surface area up to 50 m2/g. Reduction of samples at 400–500°C lead to the formation of Ni–Ru alloy nanoparticles strongly bound with the surface of oxide nanocomposite. Catalytic tests in ethanol steam reforming reaction at 500–600°C showed the highest specific activity of the sample prepared by the sequential polymeric method due to the location of Ni- and Ru-containing perovskite mainly on the surface of the composite providing a high concentration of active metal centers. At higher temperatures for all samples, ethanol conversion approached 100% with hydrogen yield varying in the range of 65–75%. A study of spent catalysts confirmed the absence of carbon deposits after long-term catalytic tests at 650°C.

Effect of applying a calcined kaolin-based particle film on the photosynthetic capacity and growth of young eucalyptus plants

In scenarios of climatic change when increased global temperatures can be expected, it is essential to search for technologies that favor sapling survival and growth after planting and increase yield in the field. Kaolin-based particle films (KBPF) have been applied as barriers against the deleterious effects of high levels of solar radiation. The objective of the present study was to assess the effects of applying purified calcined kaolin-based particle film to young eucalyptus plants. Five treatments were carried out: 0% (just water), 3%, 5%, 7%, and 10% calcined kaolin applied to the adaxial part of the leaves. A complete randomized block design was used with five treatments and ten replicates. The plants were assessed for height, diameter at ground level, gas exchanges (net photosynthetic CO2 assimilation, stomatal conductance and transpiration), instantaneous (WUE) and intrinsic water use efficiency (IWUE), chlorophyll a fluorescence (maximum quantum yield of photosystem II (PSII) (Fv/Fm), concentration of active reaction centers in relation to the quantity of photons absorbed (RC/ABS) and the maximum ratio of quantum yields of photochemical and concurrent non-photochemical processes in PSII (Fv/F0), SPAD reading and leaf ontogeny. The 3% KBPF concentration showed the best responses in biometric assessments 80 days after planting (DAP) and were corroborated by the responses of the leaf, stem and shoot dry matter production as a whole. The leaf ontogeny assessments showed positive responses following KBPF application when considering leaf development, with 7% KBPF concentration resulting in the highest mean values. The mean specific leaf mass had negative response to high KBPF concentrations. At 60 DAP, the gas exchange variables during both assessment periods declined with an increase in KBPF concentration. Significant differences as a result of KBPF applications were found only at the start of the assessments (34 DAP) for both WUE and for IWUE. Leaf ‘greenness’ (SPAD reading) at 47 days showed a quadratic relationship in both periods. The variables of chlorophyll fluorescence showed a linear response at 34 DAP and a quadratic response 60 DAP. KBPF application increased height and diameter growth in plants treated with 3% KBPF but this response was not associated with photochemical efficiency and photosynthetic carbon assimilation values on a single-leaf basis. The best performance among the variables was provided by 3% KBPF application.

On the form of high-frequency voltage-capacitance characteristics of metal-insulator-semiconductor structures with a ferroelectric insulating layer BaxSr1-хTiO3

A model of the high-frequency impedance of metal-ferroelectric-semiconductor structures has been composed and analyzed. An algorithm is formulated for recovering the impedance of the potential drop across the ferroelectric layer, band bending in a semiconductor, the total concentration of charged boundary states and minority charge carriers on the semiconductor surface from the experimental field characteristics as a function of the voltage across the structure. The results of high-frequency measurements of the capacitance and conductivity of Ni–Ba0.8Sr0.2TiO3–Pt and Ni–Ba0.8Sr0.2TiO3–Si structures in the paraelectric phase are presented. It is shown that Si does not evolve into a state of strong depletion in the entire range of external voltages, and the capacitances of the semiconductor and the metal-ferroelectric-silicon structures practically coincide. This is due to the almost complete screening of the ferroelectric layer polarization by the charges of electron traps at the Ba0.8Sr0.2TiO3–Si contact. It is proposed to use dangling bond passivation methods realized in planar silicon technology to reduce the concentration of active trapping centers at the ferroelectric-semiconductor interface.

Radial distribution and absorption cross section of active centers in bismuth-doped phosphosilicate fibers.

Determination of the active centers distribution across the fiber core as well as calculation of absorption cross sections is a challenging task for all types of bismuth-doped fibers. This is due to the low concentration of active centers and the ability of the bismuth ions to form various centers in silica-based glasses. In this work, we demonstrate the results of experimental measurement of radial distribution of bismuth active centers associated with phosphorus in fiber core using the luminescence spectroscopy. The shape of the distribution turned out to have prominent reduction of the active centers in the middle of the core. With these data, absorption cross section spectra were calculated by two methods. Both approaches demonstrated close values of absorption cross sections regardless the bismuth concentration and fiber geometry. The maximum of the absorption cross section was found to be 2.1 ± 0.3 pm2.

Polymerization Kinetics of Propylene with the MgCl2-Supported Ziegler-Natta Catalysts—Active Centers with Different Tacticity and Fragmentation of the Catalyst

The catalytic activity and stereospecificity of olefin polymerization by using heterogeneous TiCl4/MgCl2 Ziegler-Natta (Z-N) catalysts are determined by the structure and nature of active centers, which are mysterious and fairly controversial. In this work, the propylene polymerization kinetics under different polymerization temperatures by using Z-N catalysts were investigated through monitoring the concentration of active centers [C*] with different tacticity. SEM was applied to characterize the catalyst morphologies and growing polypropylene (PP) particles. The lamellar thickness and crystallizability of PP obtained under different polymerization conditions were analyzed by DSC and SAXS. The PP fractions and active centers with different tacticity were obtained with solvent extraction fractionation method. The catalytic activity, active centers with different tacticity and propagation rate constant kp, fragmentation of the catalyst, crystalline structure of PP are correlated with temperature and time for propylene polymerizations. The polymerization temperature and time show complex influences on the propylene polymerization. The higher polymerization temperature (60 °C) resulted higher activity, kp and lower [C*], and the isotactic active centers Ci* as the majority ones producing the highest isotactic polypropylene (iPP) components showed much higher kp when compared with the active centers with lower stereoselectivity. Appropriate polymerization time provided full fragmentation of the catalyst and minimum diffusion limitation. This work aims to elucidate the formation and evolution of active centers with different tacticity under different polymerization temperature and time and its relations with the fragmentation of the PP/catalyst particles, and provide the solutions to the improvement of catalyst activity and isotacticity of PP.

Kinetic scheme of the SDRC rubber synthesis process

The research of the chemical kinetics of the SDRC rubber synthesis is performed under the optimal water content in the conditions of the chain transfer and cross-growth reactions. The main reactions of the butadiene polymerization mechanism on a cobalt-containing catalytic system that are a chain growth, a chain transfer to monomer, a chain transfer to polymer, spontaneous chain transfer, a chain cross growth reaction are presented. The main assumptions of the presented kinetic scheme are that active centres of one type are formed at the optimum water concentration, the total concentration of active centres is constant and equal to the initiator concentration, at the optimum water concentration the process is considered “uninterrupted” (there is no deactivation). The article presents the theoretical foundations of chemical kinetics of the SDRC rubber synthesis. The cross-growth reaction of polybutadiene macromolecules is possible only through conjugated double bonds, the number of which in the macromolecule is limited. Therefore, this reaction can carry out without gelation to large monomer conversion values. In this regard, the mechanism of the butadiene polymerization reaction on a cobalt catalyst based on the cross growth reaction of “living” macromolecules with “living” and “dead” macromolecules was also considered.

Влияние кислотности на свойства алюмосиликатов, синтезированных золь-гель методом

In the present work amorphous silica-aluminas were synthesized by the coprecipitation method during the hydrolysis of an alcohol solution of tetraethoxysilane (with a tetraethoxysilane: alcohol mass ratio of 1: 1) and 6% aqueous solution of aluminum nitrate at pH values of 1, 3, and 10. The Si/Al molar ratio for all synthesized samples were 4.72 (± 0.29). The amorphous character of the investigated materials was confirmed by X-ray phase analysis. According to the results of scanning electron microscopy, it was found that the resulting powders have particles with a size of 1-20 μm. It was shown that the conditions of synthesis affected the specific surface area and porosity of the materials under study. By the method of low-temperature adsorption-thermodesorption of nitrogen it was established that silica-aluminas obtained under acidic conditions were microporous materials. For the sample obtained under alkaline conditions (pH = 10), the contribution of macropores is very significant. A decrease in surface area is observed as the pH of the synthesis increases. The Hammett indicator method was used to identify and quantify surface centers of different acidity. All studied silica-aluminas are characterized by the presence of both Brønsted basic (pKax from 7 to 12.8) and acidic (pKax from 0 to 7) centers, and Lewis basic (pKax from -4.4 to 0) with a pronounced maximum at pKax = 1.02. It was found that the synthesis conditions had a significant effect on the concentration of active centers. The values of the Hammett function are practically the same for the 3 studied silica-aluminas and describe the studied samples as materials of medium acidity. The variety of Lewis and Brønsted centers on the surface indicates the amphoteric properties of the materials under study. This gives the samples the properties of polyfunctional sorbents and catalysts.

Densification-Induced Structure Changes in Basolite MOFs: Effect on Low-Pressure CH4 Adsorption.

Metal-organic frameworks’ (MOFs) adsorption potential is significantly reduced by turning the original powder into pellets or granules, a mandatory step for their use at industrial scale. Pelletization is commonly performed by mechanical compression, which often induces the amorphization or pressure-induced phase transformations. The objective of this work is the rigorous study of the impact of mechanical pressure (55.9, 111.8 and 186.3 MPa) onto three commercial materials (Basolite C300, F300 and A100). Phase transformations were determined by powder X-ray diffraction analysis, whereas morphological changes were followed by nitrogen physisorption. Methane adsorption was studied in an atmospheric fixed bed. Significant crystallinity losses were observed, even at low applied pressures (up to 69.9% for Basolite C300), whereas a structural change occurred to Basolite A100 from orthorhombic to monoclinic phases, with a high cell volume reduction (13.7%). Consequently, adsorption capacities for both methane and nitrogen were largely reduced (up to 53.6% for Basolite C300), being related to morphological changes (surface area losses). Likewise, the high concentration of metallic active centers (Basolite C300), the structural breathing (Basolite A100) and the mesopore-induced formation (Basolite F300) smooth the dramatic loss of capacity of these materials.

Reactivity of dispersed schungite to bitumen

Some aspects of the use of schungite mineral powder to obtain effective compositions based on bitumen are considered in this paper. The high reactivity of dispersed schungite to bitumen is shown. The studies are performed by studying the water extracts from suspensions, as well as the state of the surface of the powders and the concentration of active surface centers using the indicator method of fixing the distribution of adsorption sites (DAS) in the spectrophotometric version. Based on the analysis of the results obtained it is concluded that the molecules of organic substances contained in bitumen can actively interact with the surface of schungite. At the interface between the binder and schungite the processes take place that are accompanied by the formation of a strong adsorption layer which is necessary for the formation of a high-quality and durable composite. The presented studies of asphalt binders confirm the conclusions and show that asphalt concrete pavements using shungite mineral powder will be able to work in a wider temperature range both for high summer and low winter temperatures.