Nitrogen Desorption Research Articles

Spatial confinement and electron transfer moderating Mo[sbnd]N bond strength for superior ammonia decomposition catalysis

Advanced catalysts for ammonia (NH3) decomposition reaction hold great promise in the area of renewable energy. In this work, highly dispersed molybdenum nitride (MoN/Mo2N) nanocrystals anchored on in-situ assembled two-dimensional (2D) mesoporous silica/reduced graphene oxide (rGO) hybrid nanosheets (MoN/SBA-15/rGO and Mo2N/SBA-15/rGO) were designed and synthesized as active and stable catalysts for COx-free H2 generation via NH3 decomposition. Benefiting from well-defined molybdenum nitride nanocrystals and moderate MoN band strength, the nanohybrids exhibited superior catalytic property, especially Mo2N/SBA-15/rGO with the highest NH3 decomposition rate of 30.58 mmol g−1cat min−1 among any Mo-based catalysts reported to date. Density functional theory (DFT) calculations revealed that the superior catalytic activity for Mo2N compared to MoN stemmed from a large reduction of kinetic energy barriers of dehydrogenation and nitrogen desorption. Moreover, the introduction of rGO can effectively weaken the associative desorption of adsorbed N atoms and thus improve NH3 decomposition activity. This study highlights the importance of designing spatially confined metal nitrides for enhancing energy catalysis.

Exploring the relationship between the physical properties of activated carbon catalysts and their efficiency in catalyzing hydrogen iodide decomposition to produce hydrogen

Using simple and efficient methods to synthesize biological activated carbon catalysts (ACCs) with the decomposition of hydrogen iodide (HI) in the sulfur-iodine cycle as a typical reaction is urgently needed for the commercialization of hydrogen energy production and development. In this study, a series of ACCs with different specific surface areas (SSAs) and pore structures are prepared by comparing and controlling the changes in carbonization and activation methods of activated carbon (AC) preparation process. Hierarchical porous AC with larger SSA has higher HI decomposition efficiency. The representative samples H240H1h and H240C4h are hierarchical porous ACCs with 48.96% and 46.88% micropores, respectively, and have the highest catalytic activity in the entire series. The nitrogen adsorption and desorption curve is combined with pore size distribution data and analyzed using the capillary aggregation (Kelvin) and monolayer adsorption (Langmuir) theories. And ACC pore grading coefficient—which can improve data visualization—is introduced.

Study on Oxygen Reduction Method of Phosphorus-doped Hydrogenated Nano-silicon

In recent years, hydrogenated nano-silicon has attracted much attention due to its high specific energy density. However, the slow kinetic oxygen reduction reaction (ORR) and oxygen evolution reaction (ORE) reduce the efficiency of hydrogenation of nano-silicon and hinder its practical application. The development of non-precious catalysts with excellent performance and low price is of great significance to the development of hydrogenated nano-silicon. Among many hydrogenation nano-silicon catalysts, cobalt-based compounds have good ORR and ORE catalytic performance, and are rich in Co reserves and low in price. Especially doped compounds have excellent stability. In the thesis, three series of hydrogenated nano-silicon composite materials of Co-SrCO3/NC, Co-Nd/NC and Co-Ce/NC were successfully synthesized through heating reflow method and subsequent high-temperature calcination. XRD, Raman, XPS, TEM, nitrogen isothermal adsorption and desorption and other analytical methods were used to characterize the structure of the above composite materials. Through chemical tests, the composite materials were evaluated for the catalytic performance of ORR and ERR, and their structure-activity relationship was analyzed. The Co_SrC03/NC series composite materials were calcined at different temperatures. The results showed that the generated SrCO3 nanorods were embedded in the graphite shell and contacted with hydrogenated nano-silicon. In an oxygen-saturated 0.1MKOH solution, Co-SrCO3/NC series composites have excellent ORR/ORE catalytic activity, especially Co-SrCO3/NC-600 has more stable activity than precious metal catalysts of 20wt% Pt/C and Ir02. Sex. The air prepared with Co-SrCO3/NC-600 has better performance. During the in-depth study of 10mA_cnT2, Co-SrC03/NC-600 was used as the air to maintain a stable platform of 1.10V, and the platform of 20wt%Pt/C under the same conditions was 1.17V.

Preparation of Functionalized Mesoporous Silica as a Novel Carrier and Immobilization of Laccase.

Amino-modified mesoporous silica (SBA-15-NH2) was prepared by hydrothermal method, which is a kind of excellent carrier for enzyme immobilization. The structure of SBA-15 was characterized by SEM and FTIR, which proved that amino group was successfully attached to the surface of SBA-15. The carrier had good mesoporous structure proved by nitrogen adsorption and desorption test. Using SBA-15-NH2 as the carrier, the optimal conditions of laccase immobilization by two different cross-linking methods were explored. At the same time, the properties of the immobilized enzyme and free enzyme were compared. The results showed that the activity of immobilized laccase by two-step method (2977.5 U/g) was much higher than that by one-step method (239.5 U/g). The optimal conditions were as follows: free laccase (35°C, pH=4.5), two-step immobilized laccase (40°C, pH=4.0), one-step immobilized laccase (35°C, pH=4.0). The two-step method was more adaptable to temperature. The pH adaptation range of the immobilized enzyme is wider, and the thermal stability is greatly enhanced. After five cycles of repeated reaction, the residual enzyme activity of two-step and one-step methods was 56% and 43% of the original. The treatment of simulated wastewater containing 2,4-dichlorophenol (2,4-DCP) by immobilized laccase was also studied. Under optimum conditions (40°C, pH=5.0, 20 mg/L), the removal of 2,4-DCP reached 89.06%. The immobilized laccase is really effective for treatment of 2,4-DCP-containing wastewater.

Biochar Derived from Agricultural Wastes as a Means of Facilitating the Degradation of Azo Dyes by Sulfides

Dyes are common contaminants, some of which are teratogenic, carcinogenic, and causative of ecological damage, and dye wastewater often contains toxic sulfides. Biochar has been widely used for the adsorption and catalysis degradation of pollutants, including dyes and sulfides, due to its abundant surface functional groups and large specific surface area. Therefore, the simultaneous treatment of dyes and sulfides with biochar may be a feasible, effective, and novel solution. This study sought to utilize low-cost, environmentally friendly, and widely sourced biochar materials from agricultural wastes such as corn stalk, rice chaff, and bean stalk to promote the reduction of dyes by sulfides. Through the action of different biochars, sulfides can rapidly decompose and transform oxidizing dyes. The RCB800 (rice chaff biochar material prepared at 800 °C) was observed to have the best effect, with a degradation rate of 96.6% in 40 min and 100% in 50 min for methyl orange. This series of materials are highly adaptable to temperature and pH, and the concentration of sulfides has a significant effect on degradation rates. Compared with commercial carbon materials, biochars are similar in terms of their catalytic mechanism and are more economical. Scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption and desorption characterization results indicated that biochar contains more pores, including mesopores, and a sufficient specific surface area, both of which are conducive to the combination of sulfides and dyes with biochar. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy showed that there are oxygen-containing functional groups (examples include quinones and carboxyl groups) on the surface of biochar that promote the reaction of sulfide and dye. The formation of active polysulfides also potentially plays an important role in the degradation reaction. This article outlines a new method for improving the degradation efficiency of azo dyes and sulfides via biochar materials derived from widely sourced agricultural wastes.

Facile synthesis of Pt–Ce0.63Zr0·37O2–Y catalysts and the application in catalytic oxidation of toluene

In this work, a series of Pt–Ce0.63Zr0·37O2–Y catalysts were prepared by unique simple mechanical mixing method. The catalytic activity of these catalysts for toluene oxidation was investigated. The physicochemical properties of the catalysts were characterized by XRD, ICP-MS, SEM, TEM, XPS and N2 sorption. Pore size distribution was analyzed according nitrogen adsorption and desorption isotherms. The catalytic results showed that using NaY as support for Pt–Ce0.63Zr0·37O2–Y could enhance the conversion of toluene during the oxidation process in comparison with HY. Further mixing cerium zirconium solid solution with Pt–NaY can improve the oxidation catalytic property of these catalysts. The conversion of toluene over Pt–Ce0.63Zr0·37O2–NaY reached more than 90% at 200 °C. High catalytic stability was obtained for toluene oxidation over Pt–Ce0.63Zr0·37O2–NaY. Platinum, cerium and zirconium can be uniformly dispersed on Y zeolite with small particle size by simple mechanical synthesis. The effect of drying methods on catalytic activity and hydrothermal stability of catalysts were also investigated in this research.

Study on the microscopic pore structures of the four different kinds of lithological reservoirs in the basin of Western China

In the basin of western China, four different kinds of lithological reservoirs are developed, including low-permeability sandstone, sedimentary tuff, shale and volcanic rock. There is generally a large difference in the micropore structure characteristics and distribution laws due to different reservoirs. The reserving capacity as well as the porous flowability, mechanism and laws are determined by the micropore structure characteristics and distribution laws of hydrocarbon reservoirs. Low-temperature nitrogen adsorption and desorption technology, high-pressure mercury injection experiment and nuclear magnetic resonance (NMR) testing technology are applied to study the micropore size, quantity, structure and distribution laws of four different kinds of lithological reservoirs as well as their similarities and differences of corresponding relation with macroporosity–permeability physical parameters. This paper also studies the movable fluid and nonlinear seepage flow characteristics of four different kinds of lithological reservoirs.

Nitrogen, Phosphorus, and Potassium Adsorption and Desorption Improvement and Soil Buffering Capacity Using Clinoptilolite Zeolite

The physical and chemical properties of clinoptilolite zeolite can be used to enhance soil nutrient availability for optimum crop use. Amending nitrogen, phosphorus, and potassium fertilizers with clinoptilolite zeolite could create a pool of negative charges to retain and release nutrients timely for crop use. Thus, we used clinoptilolite zeolite to enhance Typic Paleudults sorption (adsorption and desorption) of nitrogen, phosphorus, potassium, and this soil’s pH buffering capacity. The treatments evaluated were: (i) 250 g soil alone, (ii) 20 g clinoptilolite zeolite alone, (iii) 250 g soil + 20 g clinoptilolite zeolite, (iv) 250 g soil + 40 g clinoptilolite zeolite, and (v) 250 g soil + 60 g clinoptilolite zeolite. Clinoptilolite zeolite increased soil nitrogen and potassium adsorption, nitrogen desorption, and soil pH. Moreover, ability of the soil to resist drastic change in pH (pH buffering capacity) was improved. Additionally, phosphorus adsorption and desorption of phosphorus and potassium were reduced. Higher potassium adsorption with lower potassium desorption suggests that the clinoptilolite zeolite sorbs potassium effectively. The clinoptilolite zeolite nitrogen, phosphorus, and potassium contributed to the reduction in the adsorption these nutrients. The clinoptilolite zeolite improved nitrogen, phosphorus, and potassium availability and soil buffering capacity to prevent these nutrients from being fixed or lost through for example, leaching. Therefore, clinoptilolite zeolite application could contribute to improved use of nitrogen, phosphorus, and potassium fertilizers to prevent soil, air, and water pollution. Additionally, our intervention could improve nitrogen, phosphorus, and potassium use efficiency.

An approach to the synthesis and characterization of HMS/Pr-Rh-Zr as efficient catalyst for synthesis of tetrahydrobenzo[b]pyran and 1,4-dihydropyrano[2,3-c]pyrazole derivatives

The aim of present investigation is the synthesis of mesoporous catalyst based on hexagonal mesoporous silica. HMS support has exceptional properties such as easy synthesis, high surface area, large pore volume and wormhole pores. These distinctive characteristics beseem use of it as a support for synthesis of heterogeneous catalyst. With functionalization of HMS and immobilization of Zr-rhodanine complex into functionalized HMS, HMS/Pr-Rh-Zr was obtained. New synthesized catalyst (HMS/Pr-Rh-Zr) characterized by FT-IR, XRD, TGA, SEM, EDX, adsorption–desorption of nitrogen at 77 K and ICP techniques. These techniques confirmed that the heterogeneous catalyst of HMS/Pr-Rh-Zr was successfully synthesized. Also the catalytic activity of HMS/Pr-Rh-Zr is investigated for the synthesis of tetrahydrobenzo[b]pyran derivatives from reaction between aldehyde, malononitrile, dimedone in PEG at 80 °C and synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives from reaction between aldehyde, ethyl acetoacetate, malononitrile and hydrazine hydrate in H2O:EtOH at 35 °C. These results confirmed the HMS/Pr-Rh-Zr exhibited good catalytic performance. Furthermore, the synthesized heterogeneous catalyst could be recovered after the reaction and reused several times without any noticeable loss in activity. Also zirconium leaching of HMS/Pr-Rh-Zr was studied whereupon metal leaching of the catalyst was very low.

A new method for synthesis of a HMFI/SiC composite

HMFI/SiC composites show considerable potential for applications in heterogeneous catalysis due to the combination of the high catalytic performance of HMFI zeolites and the high thermal conductivity, mechanical strength, high-temperature resistance, and good chemical stability of SiC. Herein, we report for the first time the fast synthesis of HMFI/SiC composites directly in proton form under microwave irradiation without the addition of seed crystals. The preferable conditions for producing HMFI/SiC directly in proton form are 3 h at 190–200 °C. The structure and properties of the synthesized HMFI/SiC were determined by X-ray diffraction, scanning electron microscopy, low-temperature adsorption-desorption of nitrogen and temperature-programmed desorption of ammonia.

A comparison study of three fluxing agents in promoting properties and environmental safety of bricks incorporating hazardous waste

The incorporation of hazardous solid waste in fired bricks fabrication is a viable way. However, the physical and mechanical properties of products were negatively influenced due to the involvement of hazardous solid waste. Three fluxing agents, waste glass powder (WGP), Na-feldspar and K-feldspar, were introduced in this study to eliminate these negative influences. Physical and mechanical properties were tested by standard method. Microstructure and pore structure of bricks were conducted by Scanning Electron Microscopy (SEM) and nitrogen adsorption and desorption isotherm. The change in mineral phase was detected by X-Ray Diffraction (XRD). The leaching toxicity of heavy metals were carried out by Toxicity Characteristic Leaching Procedure (TCLP) and Netherlands tank leaching test . The introduction of fluxing agents can greatly promote effectively compressive strength and decline water absorption. When 30 wt% (weight percent) of fluxing agents are added, water absorption reduced by more than 50%, and compressive strength increased by more than one time. XRD and SEM analysis showed that fluxing agents can promote the formation of glass-ceramic phase, which were mainly formed by the self-melting reaction of fluxing agents and the interaction with silicon-aluminium oxides. These dense glass phases could reduce the porosity and promote the compactness of microstructure. The formation of glass-ceramic phases could also reduce the leachability risk of heavy metals. Combing with properties of brick and price of fluxing agents, WGP is considered to be more suitable for improving properties of fired bricks containing hazardous waste . This study could provide some useful parameters and knowledge for improving properties and leaching toxicity risk when hazardous wastes were utilized in the production of fired brick. Fluxing agents can reduce water absorption substantially. Fluxing agents can promote compressive strength remarkably. Microstructure become homogeneous and dense due to fluxing agents Fluxing agents can decrease leachability of heavy metals

In situ preparation of metal-free cPANI-GP electrode and catalytic performance in an electro-Fenton system

Most of the current researches still stay at attaching the catalyst to the sheet electrode through an additional binder, which is an inefficient and complicated process that also affects the stability of the electrode. In this study, porous graphite particles (GP) were used as the carrier, and in situ growth method was used to prepare PANI-GP electrodes which was carbonized to prepare a nitrogen-doped modified cPANI-GP electrode with a large specific surface area. Then controlling the carbonization temperature, 700cPANI-GP with high content of pyridinic N is prepared. GP, PANI-GP and cPANI-GP were characterized by scanning electron microscope, Raman spectroscopy, X-ray electron energy spectroscopy and nitrogen desorption adsorption. The existence of hydroxyl radical (·OH) was identified by electron spin resonance technique. And, the phenacetin (PNT) was used as the target pollutant to confirm the electrocatalytic performance of the particle electrode. The results show that in the electro-Fenton system with a 700cPANI-GP cathode, the degradation rate of PNT and the removal rate of COD reach 92.1% and 83.3% in 2 h, respectively, when the pH is 3 and the current density is 7 mA cm−2. And, in the reaction system using 700cPANI-GP electrode as the cathode, the concentration of ·OH is largest that confirm pyridinic N is the active site that activates H2O2 into ·OH.

The Application of Copper-Gold Catalysts in the Selective Oxidation of Glycerol at Acid and Basic Conditions

The crude glycerol is produced during the transesterification of animal fats and vegetable oils, but it is a by-product of this process. Currently, its elimination is a problem in the chemical industry. The main goal of this work was the preparation, characterization and application of mesoporous cerium-zirconium oxide as supports for copper and gold species and the comparison of selected factors on the properties of catalysts in glycerol oxidation in the liquid phase. The samples were characterized using adsorption and desorption of nitrogen, XRD, UV-vis, XPS, TEM, SEM, and STEM-EDXS. The obtained results of glycerol oxidation show that the bimetallic copper-gold catalysts are more active and selective to glyceric acid in this reaction than analogous monometallic gold catalysts. Additionally, bimetallic catalysts are also characterized by the catalytic stability, and their application leads to the increase of selectivity to glyceric acid during their reusing in glycerol oxidation in alkali media. In this work, the influence of selected factors, e.g., oxygen source and its pressure, solution pH, and base content on the catalytic activity of bimetallic catalysts is discussed.

Probe on hard carbon electrode derived from orange peel for energy storage application

Activated non-graphitizable hard carbon using orange peel with mesoporous structure has been prepared by pyrolyzation at 700, 800, 900 °C using chemical activation method. The activated orange peel-derived hard carbon has been characterized for its mesoporous and disordered structure. TG-DSC gives the information for the changes about sample composition and thermal stability of the materials. Increasing the carbonization temperature for orange peel precursor using NaOH as activating agent, elevates the pore diameter, which thereby facilitating the insertion of Na+. Raman and X-ray diffraction confirms the presence of disordered carbon. The surface morphology of the material was analyzed by scanning eletron microsope and nitrogen (N2) adsorption and desorption analysis give the morphology, mesopore size (3.374, 3.39 and 4 nm) and surace area (60.164, 58.99 and 54.327 m2/g) of the orange peel-derived hard carbon. Hence, this work strongly evidences that the biomass-derived hard carbon with good porosity and paves way of superior electrochemical performance for emerging sodium ion batteries.

FABRICATION OF MESOPOROUS WITHIN ZEOLITE Y USING MIXED TEMPLATES

Mesoporous zeolite Y was prepared using a block copolymerand hexadecyltrimethyl ammonium bromide as mixed templates. Copolymer−ionic surfactant complexes were formed and grafted into aluminosilicate gel, introducing mesoporous into zeolite. The XRD results indicated the mesoporous sample showed high crystalline and hydrothermal stability indicating a negligible damaging effect on the framework. Nitrogen adsorption and desorption results of mesoporous zeolite showed the uniform property of mesopore size distribution in the range of 2.0-5.0 nm with a greater surface area (630 m2 g -1 ), mesopore volume (0.324 cm3 g -1 ), and mesopore area (99 m2 g -1 ). A novel method was provided to develop an available mesoporosity.

FABRICATION OF MESOPOROUS WITHIN ZEOLITE Y USING MIXED TEMPLATES

Mesoporous zeolite Y was prepared using a block copolymerand hexadecyltrimethyl ammonium bromide as mixed templates. Copolymer−ionic surfactant complexes were formed and grafted into aluminosilicate gel, introducing mesoporous into zeolite. The XRD results indicated the mesoporous sample showed high crystalline and hydrothermal stability indicating a negligible damaging effect on the framework. Nitrogen adsorption and desorption results of mesoporous zeolite showed the uniform property of mesopore size distribution in the range of 2.0-5.0 nm with a greater surface area (630 m2 g -1 ), mesopore volume (0.324 cm3 g -1 ), and mesopore area (99 m2 g -1 ). A novel method was provided to develop an available mesoporosity.

Study on synthesis and characterization of nano scale spinel Mn0.5¬Fe2..5O4 by micro-emulsion method

The single phase of Mn0.5Fe2.5O4 spinel crystals was prepared by the micro-emulsion method with the oil phase is DGDE (diethylene glycol diethyl ether). The characteristics of the materials have been determined by the X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Brunaure-Emmet-Teller (BET) nitrogen adsorption and desorption, Vibration sampling magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR). The results showed that the single phase of Fe0.5Mn0.5Fe2O4 crystalline was formed due to the substitution of Fe by Mn in the Fe3O4 crystal lattice and single phase spinel crystal is formed with the size of 6.7 nm, specific surface area ≈ 193 m2.g-1, the saturation magnetization reaches ≈ 27 emu.g-1.

Study on synthesis and characterization of nano scale spinel Mn<sub>0.5­</sub>Fe<sub>2.5</sub>O<sub>4</sub> by micro-emulsion method

The single phase of Mn0.5Fe2.5O4 spinel crystals was prepared by the micro-emulsion method with the oil phase is DGDE (diethylene glycol diethyl ether). The characteristics of the materials have been determined by the X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Brunaure-Emmet-Teller (BET) nitrogen adsorption and desorption, Vibration sampling magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR). The results showed that the single phase of Fe0.5Mn0.5Fe2O4 crystalline was formed due to the substitution of Fe by Mn in the Fe3O4 crystal lattice and single phase spinel crystal is formed with the size of 6.7 nm, specific surface area ≈ 193 m2.g-1, the saturation magnetization reaches ≈ 27 emu.g-1.

In English

The aim of the work is synthesis and study on the properties of polyfunctional magnetosensitive nanocomposites (NC) and target-directed magnetic fluids (MF) based on physiological solution (PS), magnetite, gemcitabine (GEM) and HER2 antibodies (AB), promising for use in targeted antitumor therapy against MDA-MB-231 aggressive tumor cells of triple-negative human breast cancer (BC) with high proliferative and metastatic activity. The specific surface area (Ssp) of samples was determined by the method of thermal desorption of nitrogen using a device KELVIN 1042 of “COSTECH Instruments”. The size of nanoparticles (NP) has been estimated by the formula DBET = 6/(ρSBET), where ρ is the density of NC particle, SBET is the value of the specific surface area calculated by the polymolecular adsorption theory of Brunauer, Emmett and Teller (BET). The surface condition of nanodispersed samples was studied by IR spectroscopy (“Perkin Elmer” Fourier spectrometer, a model 1720X). To calculate the concentration of hydroxyl groups on the surface of nanostructures, the method of differential thermal analysis was used in combination with differential thermogravimetric analysis. The thermograms were recorded using a derivatograph Q-1500D of MOM firm (Hungary) in the temperature range of 20–1000 °C at a heating rate of 10 deg/min. X-ray phase analysis of nanostructures was performed using a diffractometer DRON-4-07 (CuKα radiation with a nickel filter in a reflected beam, the Bragg-Brentano focusing). The size and shape of NP were determined by electron microscopy (a transmission electron microscope (TEM) JEM-2100F (Japan)). The hysteresis loops of the magnetic moment of the samples were measured using a laboratory vibration magnetometer of Foner type at room temperature. Measurement of optical density, absorption spectra and GEM concentration in solutions was performed by spectrophotometric analysis (Spectrometer Lambda 35 UV/Vis Perkin Elmer Instruments). The amount of adsorbed substance on the surface of magnetite was determined using a spectrophotometer at λ = 268 nm from a calibration graph. The thickness of the adsorbed layer of GEM in the composition of Fe3O4@GEM NC was determined by magnetic granulometry. To study the direct cytotoxic/cytostatic effect of a series of experimental samples of MF based on PS, Fe3O4 NP, GEM, HER2 AB, as well as MF components in mono- or complex use, onto MDA-MB-231 cells in vitro, IC50 index was determined. MF were synthesized on the basis of single-domain Fe3O4 and PS, stabilized with sodium oleate (Ol.Na) and polyethylene glycol (PEG), containing GEM and HER2 (Fe3O4@GEM/Ol.Na/PEG/HER2+PS). The cytotoxic/cytostatic activity of MF against MDA-MB-231 cells was studied. It was found that as a result of application of synthesized MF composed of Fe3O4@GEM/Ol.Na/PEG/HER2+PS at the concentration of magnetite of 0.05 mg/mL, GEM - 0.004 mg/mL and HER2 AB - 0.013 μg/mL, a synergistic effect arose, with reduction of the amount of viable BC cells to 51 %. It has been proved that when using MF based on targeted Fe3O4/GEM/HER2 complex, the increased antitumor efficacy is observed compared to traditional use of the drug GEM, with a significant reduction (by four times) of its dose. The high cytotoxic/cytostatic activity of Fe3O4/GEM/HER2 complexes is explained by the fact that endogenous iron metabolism disorders play a significant role in the mechanisms of realization of the apoptotic program under the influence of nanocomposite. Thus, when the nanocomposite system contains Fe3O4/GEM/HER2 complexes in MDA-MB-231 cells, a significant increase is observed in the level of “free iron”, which favours formation of reactive oxygen species and causes oxidative stress (Fenton reaction). The consequences of oxidative stress are induction of apoptosis, enhancement of lipid peroxidation processes, as well as structural and functional rearrangement of biological membranes. The prospects have been shown of further studies of Fe3O4@GEM/Ol.Na/PEG/HER2+PS MF in order to create on their basis a magnetically carried remedy for use in targeted antitumor therapy.

In English

Powders where the γ≈α-Al2O3-nano phases are the priority precursors for catalysts for heterogeneous catalysis with the maximum content of surface 5-coordinated Al centers for Pt attachment. Hydrogenated nano powders (~8 nm) of γ-, γ '-, θ-, κ-Al2O3 soluble in hydrochloric acid were obtained from the processing of aluminum boride powders with an icosahedral structure. Samples, which underwent a step-by-step and single heating of 50-100K heat treatment for 2 hours at temperatures of 570-1470K, were received in quantity of 34. The specific surface area of SВET, m2g-1 was measured by the thermal nitrogen desorption express method of gas chromatography through the GC-1 device. X-ray (phase and coherent), fluorescence and phase chemical-analytical evaluation of the samples were performed. The thermokinetic characteristics of the processes are calculated using the exponential Arrhenius law. Dimensional characteristics of crystallites (10.4-48 nm); specific surface area of powders (213-8.6 m2g-1, SВET); thermokinetic parameters of α-Al2O3 crystallite growth process (V α-Al2O3 - 1.44 10-3 - 6.67 10-3 nm s-1; E α-Al2O3 = 38.7±2.1kJ mol-1; A0 = 0.16±0.0 s-1 along the temperature line 1220-1470K were determined and calculated. The process of dehydration of two OH-groups occurs in the region 570-720K Ea H2O ↑ = 30.5 ± 0.5 kJ mol-1 A0 = 1.33±0.3 s-1. The last group of OH at temperatures of 820 -1070К and a rate of 2.13 10-4 - 4.93 10-4 mol s-1 Ea H2O ↑ = 13.2 ± 0.8 kJ mol-1 A0 = 16.9 ± 0.9 s-1. The activation energy of the phase transition is Ea., γ → α-Al2O3 = 23.9 ± 1.0 kJ mol-1 A0 = 2.01 ± 0.72 s-1 (770-970K) and Ea., γ → α-Al2O3 = 83.5 ± 0.8 kJ mol-1 A0 =(2,05±0,95) 103 s-1 (1070-1170K). It agrees well with the known heat of conversion Eа, γ→α-Al2O3 = 85 kJ mol-1. The TK of γ≈α-Al2O3-nano phases is at 1170K.