Himia, Fizika ta Tehnologia Poverhni

The aim of this work was to synthesize cerium oxide nanoparticles (CeO2-NPs) using the Magnolia kobus leaves extract, to determine the composition of the extract and the participation of its components in the synthesis of NPs, to study the morphology and structure of the obtained NPs, to investigate their antibacterial activity. The composition of the plant extract and involving of its components in green synthesis of CeO2-NPs was studied by high-performance liquid chromatography (HPLC) and matrix-assisted laser/desorption ionization mass spectrometry (MALDI MS). It has been shown that the extract contained phenolic compounds (derivatives of simple phenols, flavonols, hydroxybenzoic and hydroxycinnamic acids, lignans, coumarins), as well as carotenoids, chlorophylls, terpenoids and sterols. The composition of the liquid phase from the reaction mixture (reaction liquid) after the NPs formation was studied to determine the components of the extract involved in the synthesis of CeO2-NPs. According to the results of HPLC and MALDI MS studies, significant differences were found in the composition of the plant extract and the reaction liquid: hydroxybenzoic acids, flavonoids and terpenoids disappeared or their concentration was significantly decreased, the content of lignans changed to a lesser extent, and it was observed the appearance of hydrophilic low-molecular compounds probably formed as a result of synthesis and stabilization of NPs. Synthesized CeO2-NPs were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). According to SEM and XRD, CeO2-NPs had a crystalline structure and were of spherical shape; the average size of the crystallites was ~ 20 nm, and the diameter of the primary particles was 50 ± 10 nm. It has been found that hydroxybenzoic acids, flavonoids and terpenoids are active participants in the green synthesis of CeO2-NPs in the presence of Magnolia kobus leaves extract, while lignans (fargesin/kobusin and eudesmin) are involved in less extend in the reduction/stabilization of CeO2-NPs. The synthesized particles possess antibacterial properties and can be used in the preparation of materials for medical and biological purposes.

T. V. Fesenko

I. V. Laguta

O. M. Stavinskaya

P. O. Kuzema

V. M. Anishchenko

O. I. Oranska

R. V. Ivannikov

O. A. Diyuk

I. O. Skorochod

Himia Fizika ta Tehnologia Poverhni

Green synthesis of antibacterial cerium oxide nanoparticles using Magnolia kobus leaves extract

利用日本厚朴叶提取物绿色合成抗菌氧化铈纳米颗粒

The influence of the Nernst diffusion layer thickness on the surface concentrations of electroactive and electroinactive species in a model electrochemical process with a preceding homogeneous first-order chemical reaction under application of a small amplitude alternating current has been investigated. A case of equal diffusion coefficients of species taking part in the preceding chemical reaction in a thin layer attached to a planar electrode is considered. It has been shown that, at low frequencies of an applied alternating current, the surface concentrations of electroactive and electroinactive species increase with increasing the Nernst diffusion layer thickness. At high frequencies, the surface concentrations of both species do not depend on this parameter. However, there is a range of frequencies where the surface concentrations of species can decrease with increasing the Nernst diffusion layer thickness. This range of frequencies can be influenced by a value of the Nernst diffusion layer thickness, the rate constants of chemical reaction, and the diffusion coefficient of species. There exists a phase shift between an alternating current and the surface concentrations of electroactive and electroinactive species that change under application of this current. It is a function of the Nernst diffusion layer thickness, the oscillation diffusion layer thickness, and the reaction layer thickness. In the case of electroactive species, the phase angle can take only a positive value. At low frequencies, it tends to π/2, whereas at high frequencies it decreases to π/4. For the case of electroinactive species, the phase angle can be positive, negative, and equal to zero depending on the value of the Nernst diffusion layer thickness, the rate constants of chemical reaction, and the diffusion coefficient of species. It approaches –π/2 at low frequencies, and at high frequencies it tends to π/4. The both phase angles can have the maxima and the minima. Their values are strongly dependent on the Nernst diffusion layer thickness, the diffusion coefficient of species, the rate constants of chemical reaction.

O. I. Gichan

Influence of the Nernst diffusion layer thickness on surface concentration in a model electrochemical process with a preceding chemical reaction

Nernst扩散层厚度对具有前置化学反应的电化学过程中表面浓度的影响

The present work is the first case where the adsorptive removal of the most commonly used fluoroquinolone antibiotic - levofloxacin (&gt; 80 % unmetabolized in the urine) from aqueous solution as a model of wastewater treatment plant effluent by natural zeolite – clinoptilolite and its acid-modified form has been investigated under static and dynamic conditions. The effect of the inlet concentration, the flow rate and the pH value of antibiotic influent solution, also, the contact time of system zeolite/antibiotic solution on the adsorption process were examined and evaluated using the Langmuir adsorption model. The adsorption mechanism mainly composed of electrostatic interaction between the zeolite surface and adsorbate - levofloxacin. This study demonstrates and proves that natural clinoptilolite and its acid-modified form could be an efficient, eco-friendly, alternative and competitive adsorbent in terms of cheapness, selectivity and adsorption efficacy for the removal of levofloxacin from wastewaters and implemented in an industrial setting and wastewater treatment plant for purification processes.

I. Rubashvili

M. Zautashvili

T. Kordzakhia

K. Ebralidze

Adsorption study of fluoroquinolone antibiotic - levofloxacin to evaluate the possibility of its removal from wastewaters using natural zeolite

天然沸石去除废水中氟喹诺酮抗生素——左氧氟沙星的吸附研究

Silicas of MCM-41‑type with reactive functional groups are widely used as starting substrates in large variety of post‑synthetic chemical modification pathways. Therefore, variation of their structural characteristics in the process of templated sol‑gel synthesis or post-synthetic treatment is of great importance. The aim of this work was to elucidate the influence of template agent selection on structural features of MCM-41‑type materials with surface silanol and 3‑chloropropyl groups. For this purpose, template-assisted sol-gel condensation of structure forming silanes (tetraethyl orthosilicate and 3‑chloropropyltriethoxysilane) was carried out in the presence of decyltrimethylammonium bromide as structure-directing agent. The capability of cyclic oligosaccharide (β-cyclodextrin) to interact with surfactant micelles in the process of hydrothermal sol-gel synthesis and to influence the formation of mesoporous structure of silica materials was studied. The IR spectroscopy was applied to carry out control under the complete removal of template moieties from pores by extraction procedure and to confirm introduction of 3‑chloropropyl groups into the surface layer of synthesized silicas. Arrangement of mesoscale pores and structural parameters were estimated from the results of X‑ray diffraction and low-temperature adsorption-desorption of nitrogen. It has been found that β‑cyclodextrin as component of hybrid template has positive effect on porous structure of 3-chloropropyl-functionalized MCM-41-type silica causing increase of surface area accompanied with preservation of pore ordering. Moreover, both ionic surfactant and oligosaccharide components of hybrid template act as porogens during sol-gel condensation of structure forming silanes enable to prepare silica materials with micro-mesoporosity. Proposed approach can be useful in synthesis of MCM‑41‑type silicas with surface linker groups and controlled structural characteristics (pore size, geometry and ordering), which have great potential as substrates in design of sophisticated materials.

N. V. Roik

I. M. Trofymchuk

L. O. Belyakova

Hybrid template directed hydrothermal synthesis of MCM-41 silicas with surface silanol and 3-chloropropyl groups

表面含硅醇和3-氯丙基的MCM-41硅的混合模板定向水热合成

Molecular models for tin dioxide nanoparticles containing 1-7 metal atoms and coordinated or constitutive water have been constructed. Dependent on the composition of the models, the coordination number of the tin atom varied from 4 to 6, and that of oxygen was 2 or 3. The considered models contained both terminal (Sn–OH) and bridging (Sn–OH–Sn) hydroxyl groups, and also bridging (Sn–O–Sn) groups. Their equilibrium spatial and electronic structures were calculated using the second-order Møller-Plesset perturbation theory method with the SBKJC valence-only basis set. To assess the gas-phase acidity of the dioxide surface, the deprotonation energy of the studied models was determined. The adsorption energy of water molecules and hydroxide ions on aprotic (incompletely coordinated) tin atoms, which act as Lewis acid centers, was calculated. In order to estimate the pKa value of the surface of tin dioxide, the Gibbs free energy was calculated for the process of formation of ion pairs due to the proton transfer from hydroxyl groups to adsorbed water molecules. Based on the analysis of the energy effects of the coordination of water molecules and of hydroxide ion, the removal of a proton and its transfer on the hydrated surface of tin dioxide, quantitative estimates have been made of the acid-base characteristics of the active sites of the SnO2 surface. The dependence of the acidity of hydroxyl groups and coordinated water molecules on the coordination number of the oxygen atom and the neighboring tin atom, as well as on the dimensions of the cluster model, was revealed. It is shown that the acidity of protonic and aprotic sites naturally decreases with an increase in the coordination number of the tin atom. The method of calculating the value of pKa used in the work for the smallest model of the SnO2×2H2O composition allows one to reproduce the experimental data for stannic acids.

O. V. Filonenko

A. G. Grebenyuk

M. I. Terebinska

V. V. Lobanov

Quantum chemical simulation of acid-base properties of the surface of SnO2 nanoparticles

SnO2纳米颗粒表面酸碱性质的量子化学模拟

With the development of nanotechnology, new scientific directions have been initiated and a significant amount of researches has been carried out, dedicated to the creation and search for promising applications in medicine, in particular, oncology, of nanocomposites based on bioinert, biocompatible and bioactive nanoparticle materials and modern chemotherapeutic drugs with different mechanisms of action. These works contain data indicating the advantages to introduce nanocomposite drugs into clinical practice, compared to the traditional use of chemotherapeutic drugs. The research results confirm the priority of works in the field of creation of new nanocomposite chemotherapeutic drugs for use in antitumor therapy and overcoming of drug resistance of malignant cells and neoplasms. The purpose of the review is to generalize and analyze the authors’ experimental works performed at Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, concerning the specifics of the effect of chemotherapeutic drugs with different mechanisms of action and related nanocomposites, on cellular systems and tumors. Such data are relevant to determine promising directions and ways of creation of new effective nanocomposite drugs for use, in particular, in antitumor chemotherapy. At Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, using the chemical engineering method, magnetically sensitive core-shell nanocomposites were synthesized with a multi-level hierarchical nanoarchitecture capable of performing a complex of diagnostic and therapeutic functions with various mechanisms of action, characteristic of medico-biological nanorobots. Their use makes it possible to implement the principle of targeted delivery of antitumor drugs, to carry out real-time local therapy by various methods and MRI diagnosis of the disease, to realize the synergy of treatment with antitumor drugs of different mechanisms of action, to reduce the toxic side effects of oncological drugs on the body. The combination of the above features of nanocomposites, as well as their role in overcoming the drug resistance of cells of malignant neoplasms to cisplatin, testify to the perspective of creation and research of nanocomposite drugs in solving the problem of increase in the efficiency of chemotherapy.

S. P. Turanska

T. V. Krupska

V. V. Turov

P. P. Gorbyk

Increase in efficiency of chemotherapeutic drugs: physico-chemical factor

化疗药物效率的提高：物理化学因素

The development of catalytic methods for xylose transformation as renewable raw material into value-added chemicals such as lactic and glycolic acid esters has been the subject of intensive research in recent years. Thus, methyl lactate and methyl glycolate are used as a starting material for the production of lactide and glycolide – an important monomers for the production of biodegradable polymers. The aim of this work was to search of simple effective catalyst for transformation of xylose into methyl esters of lactic and glycolic acids. For this purpose, tin-containing alumina doped with СeO2, MoO3 and CuO oxides were synthesized by impregnation method. Textural and structural parameters of obtained МeO‑SnO2/Al2O3 mixed oxides were estimated from the results of low-temperature adsorption-desorption of nitrogen and X-ray diffraction. The formation of morphology ceria close to octahedra for CeО2‑SnO2/Al2O3 sample is confirmed by the X-ray phase analysis data and SEM microphotographs. The UV spectroscopy data indicates the nanosize of tin dioxide particles on the γ‑Al2O3 surface. According to the titration results, CeО2‑SnO2/Al2O3 is acid mixed oxide with H0 ≤ –3.0. The catalytic conversion of xylose solution in methanol was carried out in rotated autoclaves and in a flow stainless steel reactor with a fixed bed of catalyst. The products of the target reaction C5H10O5+2CH3OH+1/2O2 = C4H8O3+C3H6O3+2H2O were analyzed by 13C NMR. It was found that a complete conversion of 4 % xylose solution in a 70 % aqueous methanol solution occurs with the formation of methyl lactate (42 %) and methyl glycolate (24 %) on the developed CeO2-SnO2/Al2O3 catalyst loading of 3.5 mmol C5H10O5/gcat/h at 190 °C/3.0 MPa in air flow. The path of the reaction is proposed, namely: the IVSn4+ ions in CeO2-SnO2/Al2O3 catalyst as Lewis acid sites promote retro-aldol xylose condensation and further Cannizzaro rearrangement of intermediate methyl pyruval hemiacetal into methyl lactate. And CeO2 provides selective oxidation of glycol aldehyde formed as a result of aldol decondensation of xylose to methyl glycolate.

S. V. Prudius

N. L. Hes

A. Yu. Zhuravlov

V. V. Brei

Oxidation of xylose – methanol mixture into methyl lactate and methyl glycolate on CeO2-SnO2/Al2O3 catalyst

木糖-甲醇混合物在CeO2-SnO2/Al2O3催化剂上氧化生成乳酸甲酯和乙醇酸甲酯

Caffeic acid (CA) is a phenolic, natural, biologically active compound with pronounced antioxidant and antimicrobial properties. It has a great potential for use in medicine and cosmetology and can also be used to obtain a number of other useful chemicals. Therefore, research aimed at improving the technologies for removing caffeic acid from plant raw materials and its processing is relevant. In our work, we have studied the complexes of caffeic acid with nanosized Al2O3, which is usually used in various plant biomass conversion technologies, using FT-IR spectroscopy, temperature-programmed desorption mass spectrometry (TPD MS), and DFT calculations. The FT-IR spectra analysis shows that CA can interact with aluminum oxide via both the carboxyl and phenolic groups. Based on the measured differences between carbonyl symmetric and asymmetrc vibrational peaks (Δν), it was found that carboxylate complexes of CA on the Al2O3 surface can have bidentate and monodentate structures. The mass spectrometric data analysis made it possible to identify compounds of 4-vinyl catechol, pyrocatechol, and phenol, which are decomposition products of the formed carboxylate and phenolic complexes. It was found that on the surface of the studied CA/Al2O3 samples, CA chelate complexes, formed with the participation of both OH groups of the aromatic ring, predominate.

N. S. Nastasiienko

T. V. Kulik

M. M. Ilchenko

B. B. Palianytsia

A. I. Nastasiienko

G. Shaw

P. R. Davies

D. Wass

M. T. Kartel

Caffeic acid complexes over alumina surface: FTIR, TPD MS and DFT calculations

咖啡酸在氧化铝表面上的复合物：FTIR、TPD MS和DFT计算

The present research is devoted to the investigation of a nanosystem including gold nanoparticles in an aqueous solution of sodium sulfacetamide in order to determine the nature and efficiency of their interaction depending on the concentration and pH of the medium. Sodium sulfacetamide is of interest due to the possibility of its use in the composition of new hydrogel materials with incorporated gold nanoparticles for the development of ophthalmic implants. Gold nanoparticles with an average size of 20 nm, obtained by hydrothermal synthesis, were used. The study of the cytotoxicity of sodium sulfacetamide based on the integral index of the metabolic activity of MA-104 cells established concentrations that are the basis for explaining the possible toxic effect of materials impregnated with sodium sulfacetamide solutions. The concentration of 0.1 % sodium sulfacetamide solution after 24 hours of contact with cells and 0.05 % after 48 hours of contact should be considered as indifferent. The effectiveness of the interaction of sodium sulfacetamide and gold nanoparticles was evaluated by UV-Vis spectroscopy, electrokinetic measurements and scanning electron microscopy. Spectral studies of a suspension of gold nanoparticles in sodium sulfacetamide solutions in the range of therapeutic concentrations of 5.0÷30.0 % revealed a non-monotonic concentration-dependent effect of the sulfonamide medicine on the absorption intensity in the visible and ultraviolet ranges. The broadening of the spectral band of the surface plasmon resonance of gold nanoparticles in the presence of increasing concentrations of sulfacetamide and the appearance of an absorption band in the long-wave region were found. The peak shifts in the UV spectra after the addition of gold nanoparticles to sodium sulfacetamide were estimated. An increase in the negative value of the electrokinetic potential of gold nanoparticles under the influence of sulfacetamide from –26.2 mV to –41.4 mV was found. The data obtained indicate the existence of a chemical interaction between gold nanoparticles and sodium sulfacetamide solutions, which makes it possible to determine the conditions of their use in composite materials for biomedical purposes to reduce toxicity and leaching rate.

V. I. Podolska

L. S. Rieznichenko

L. M. Yakubenko

T. G. Gruzina

N. M. Zholobak

Yu. M. Samchenko

S. M. Dybkova

A study on the interaction of gold nanoparticles with sodium sulfacetamide

金纳米颗粒与磺胺醋酰钠相互作用的研究

The aim of the work was to investigate the possibilities of obtaining activated carbon materials (AC) with controlled nanoporosity dependent on the raw materials used by involving an innovative method of its production and confirming the effect of reducing the density of the liquid under the action of the adsorption potential of the pore walls by means of modeling by the Boltzmann lattice method within the framework of a two-dimensional model. The results of the study showed that depending on the raw material used (chips of various hardwood species) and the method of its primary processing (involving an innovative method of its production, shear deformation, in particular), it is possible to obtain AB with a different ratio of micro- and mesopores, from almost completely microporous samples to samples with developed mesoporosity. It is shown that during carbonization, the organic matter that blocked the pores of the tubular structure is removed, forming open holes. Data infrared (IR) Fourier spectroscopy confirm that the formed surface of the micro-mesoporous sorbent must actively interact with polar and non-polar adsorbates with the help of surface functional groups, which corresponds to the results obtained in the work on the structural and sorption parameters of AB. The liquid density distribution along the pore axis of the mesoporous matrix was calculated by modeling using the Boltzmann lattice method, dependent on the initial wetting angle and capillary size. It is shown that in nanopores of small size (10 nm) the density of the liquid phase gradually decreases and at a certain depth of the pore its jump-like drop occurs, which reflects the presence of a phase transition to intense vaporization. So, the mechanism of purification of aqueous solutions from harmful impurities by nano-sized pores due to the effect of reducing the density of the liquid under the action of the adsorption potential of the pore walls has been confirmed. The micro-mesoporous AB obtained in the work can be used for the production of a wide range of matrix and composite materials with controlled nanoporosity. They are promising sorption materials, as they are characterized by lower diffusion complications during adsorption. And the effect of reducing the density of the liquid under the influence of the adsorption potential of the pore walls well explains the possible mechanism of cleaning contaminated aqueous liquids with the help of a mesoporous matrix.

O. O. Efremov

V. V. Kusturov

O. B. Loginova

V. E. Diyuk

S. P. Starik

A study on the adsorption capacity of carbon materials obtained from different plant raw materials

不同植物原料制备的碳材料吸附性能研究

出版信息	出版商: Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine，出版周期: ，期刊类型: journal，开源期刊: 否
基本数据	创刊年份: 2019，原创研究文献占比: ，自引率:， Gold OA占比:

Himia, Fizika ta Tehnologia Poverhni

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