IR Fourier Spectroscopy Research Articles

The Use of IR Fourier Spectroscopy of Saliva for Rapid Assessment of the Level of Lipid Peroxidation Products

Infrared spectroscopy of saliva is an express and non-invasive method of analysis, applicable for diagnostics of various diseases and for studying metabolic processes and adaptive changes in the body. The goal of this study was to determine possibility of analyzing the products of lipid peroxidation (LPO) by using IR spectroscopy of saliva on the example of oncological diseases. The study involved 203 patients with lung cancer (n = 40), breast cancer (n = 50) and the control group (n = 113). Saliva samples were collected in the morning after overnight fast. The content of LPO products (conjugated dienes, and trienes, Schiff bases, malonic dialdehyde MDA) was determined in all samples and the IR absorption spectra were recorded in the range of 500–4000 cm–1. In the IR spectra, an increase in the intensity of the absorption bands of lipids was observed; it corresponded to an increase in the total lipid content and correlated with the content of MDA, and a decrease in the intensity of vibrations of oxygen-containing groups, which corresponded to a negative correlation with secondary LPO products. Apparently, on the IR spectra, we simultaneously register both primary, intermediate, and final LPO products. Statistically significant regression equations were obtained, allowing to estimate the content of intermediate LPO products - conjugated triene, and Schiff bases. The proposed method allows to monitor LPO processes, as well as to characterize the direction of the equilibrium shift in these processes.

FT-IR-Spectra of Multilayered Graphene and Its Composition with Surface-Active Material

Multilayer graphene has been obtained by ultrasonic splitting of graphite microparticles in a surface-active solvent that is a mixture of nonane and water and a surface-active surfactant, which provides dispersion of graphene in hydrophilic systems, has been selected. The chemical structure of the obtained materials has been investigated by IR Fourier spectroscopy. Possible mechanisms of the influence of inorganic surfactants (sodium liquid glass) on the graphene, the type of relations that arise between it and the graphene surface, and possible areas of its application have been discussed.

Исследование реакции метилового эфира ароилпировиноградной кислоты с о-замещенным анилином методом ИК-фурье-спектроскопии

Исследование реакции метилового эфира ароилпировиноградной кислоты с о-замещенным анилином методом ИК-фурье-спектроскопии

Hemocompatibility of magnetic magnethite nanoparticles and magnetite-silica composites in vitro

The goal of the present research is to study the hemocompatibility of magnetic nanoparticles (MNPs) in model systems in vitro.Materials and methods. Magnetite nanoparticles and magnetite colloidal solutions were used in 0.9% NaCl in concentrations 0.2, 2.0 and 20.0 mg/ml. The study was performed with heparinized human whole blood, 1 ml of which was mixed with 1 of ml nanoparticles/physiological solution. Measurements were made directly after mixing, and then 1, 2.5 and 5 hours later. The amount of reactive oxygen species (ROS) was measured with luminol-dependent chemiluminiscence (CL). An erythrocyte aggregation index was calculated. For the assessment of hemolytic properties, a hemolysis coefficient was calculated based on optical density of the plasma. The nanoparticless surface protein layer investigation was performed with IR-Fourier spectroscopy.Results. Nanoparticles decline CL in timeand concentration-dependent manner. Erythrocyte aggregation stability grows, but concentration and/or application time increment leads to significant hemolysis. IR-Fourier spectroscopy data shows albumin as main component of protein crown, whose conformation changes in time.Given data proves safety of studied MNPs in relation to examined parameters in low (0.2 and 2.0 mg/ml) concentrations up to 2.5 hours interaction. This allows us to treat these MNPs as a promising agents for further use in medical practice after completing examinations related to other homeostasis indicators.

Binary Polymer Systems Based on Polyvinylbutyral: FTIR Spectra, Conformational Dynamics, and Free Volume

Local molecular dynamics of polymer systems based on polyvinylbutyral is studied via the IR Fourier spectroscopy of conformation-inhomogeneous probes. The compositions of the studied binary mixtures of polyvinylbutyral with polymethylmethacrylate are 80: 20, 60: 40, 40: 60, and 20: 80. The temperatures of the secondary relaxation transitions and the difference between the enthalpies of conformation of the probe molecules in these systems are obtained. The effective sizes of mobile free-volume elements, the diffusion of which results in the transport of small molecules upon membrane gas separation, are estimated.

Isolation, purification, and investigation of some properties of glucose oxidase of the wood-degrading fungus Lentinus (Panus) tigrinus strain VKM F-3616D

The activity and some properties of glucose oxidase (EC 1.1.3.4) of the wood-degrading fungus Lentinus (Panus) tigrinus VKM F-3616D were studied. The results showed that 12 days of dynamic liquid-phase cultivation increased the activity and the biosynthetic levels of the enzyme with maximal activity at day 6. After 6 days, a decrease in the glucose oxidase activity was observed. The enzyme isolated via ion exchange chromatography had an optimal pH of 4.0 and a temperature optimum of 50 °C. Spectrophotometry, fluorescence analysis, and IR Fourier spectroscopy showed that the enzyme was a flavoprotein and that its prosthetic group contains flavin adenine dinucleotide. The relative kinetic parameters of the enzyme were determined: the Michaelis constant (Km) was 4.1 x 10-3 M, and the maximal rate of the enzymatic reaction (Vmax) was 0.36 IU. Results of electrophoresis in native and denaturing conditions were consistent with an enzyme structure having two equal subunits with a total molecular mass of approximately 160 kDa.

Erosion of rod electrodes of the air AC plasma torch

Depending on the plasma-forming mixture, various types of electrode materials are used. If air, carbon dioxide and steam are used, it is optimal to use copper electrodes, since copper has a high thermal conductivity. Copper rod electrodes of an air AC plasma torch are considered. In the binding zone of the electric arc, the electrode material melts and boils, which leads to physical erosion of the electrode. Scanning electron microscopy with elemental analysis, X-ray phase analysis and IR Fourier spectroscopy were used to analyze the products of electrode erosion. The erosion products content copper, iron, nitrogen, oxygen, and other metals from the plasma torch case.

Investigation of Supermolecular Structure of Fluorine-Containing Polyethyleneterephthalate Monofibers

The effect of a new modifier based on a polyfluorinated alcohol immobilized on montmorillonite nanoclay on the supermolecular structure of polyethyleneterephthalate was studied by Fourier IR spectroscopy, x-ray structural analysis, DSC, DMA, and atomic-force microscopy (AFM). It was established that the effect of the fluorine-containing modifier, involving reorganization of the molecular and crystal structure of the polymer, is complex in nature, leading to an increase of the degree of crystallinity and raising the level of surface uniformity in the obtained polyester nanofibers.

MODIFICATION OF TRACK-ETCHED MEMBRANES BY LOW-TEMPERATURE PLASMA

Published data appearing in the last decade on the modification of track-etched membranes with the use of low-temperature plasma are considered. Some schematic description of setups and methods for sample processing in discharges of various types in atmosphere of non-polymerizing gases and by plasma polymerization, also by using of such plasma-chemical methods as magnetron sputtering of polymer targets and electron-beam dispersion of polymers in vacuum are presented. Some modern physicochemical methods for studying of changes occurring on the surface of membranes are described. Some typical examples of changes in the contact properties of the track-etched membrane surface and their chemical composition by means of X-ray photoelectron spectroscopy and Fourier-IR spectroscopy are given. Using the methods of atomic force microscopy and electron microscopy, some examples of morphological changes occurring on the surface of track membranes and in the volume of pores are presented. It is shown that the modification of track membranes by low temperature plasma leads to the creation of “smart” membranes, which possess some unique properties. This allows to significantly expand the areas of their application. Modified membranes can be used as thermosensitive elements and mechanochemical membranes with a “chemical valve”.The plasma treatment allows also significantly change the biocompatibility of the surface of track-etched membranes and use them in medicine and biology. By means of some special techniques, studies of the adsorption and growth of cellular and biological structures on the surface of modified track-etched membranes are presented.The possibility of the modified track membranes using as a highly effective biocompatible drainage material in the surgical treatment of refractory glaucoma, as well as implants in the treatment of bullous keratopathy is shown.Forcitation:Kravets L.I.,Gilman A.B. Modification of track-etched membranes by low-temperature plasma. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 4-30

Special feature of kinetics of ZcE isomerization of β-N-methylaminovinyl trifluoromethyl ketone in Ar matrix exposed to UV radiation and spontaneous E ⇌ Z isomerization of α-methyl-β-N-methylaminovinyl trifluoromethyl ketone

Although it is well known that reactivity of α,β-unsaturated enaminoketones is closely associated with spatial and electronic structure but until now little attention was devoted to quantitative investigation of interconversion of different stereoisomeric forms of enaminoketones. In present work we studied peculiarities of kinetics of Z⇌E isomerization of enaminoketone 4-(N-methylamino)-1,1,1-trifluorobut-3-en-2-one F3C-COCHCHNH(CH3) (1) in Ar-matrix exposed to UV-radiation (λ=340nm) with IR Fourier and 2D correlation spectroscopy and we found that Z-s-Z-s-trans isomer transforms primarily into two E-isomers, E-s-E-s-trans and E-s-Z-s-trans which further turn into the E-s-E-s-cis and E-s-Z-s-cis conformers all interconversion rate constants being comparable in magnitude. Along with this process long-term exposure to the UV-radiation results in proton transfer from nitrogen of methylamino group to carbonyl oxygen with simultaneous isomerization of ‘cyclic’ iminoenol form into ‘linear‘one. In solution of enaminoketone 4-(N-methylamino)-1,1,1-trifluoro-3-methylbut-3-en-2-one F3C-CO-C(CH3)CH-NH(CH3) (2) we observed reversed process, namely, spontaneous interconversion of the E-s-E-s-trans and E-s-Z-s-trans conformers into the Z-s-Z-trans isomer. It was found that rate constants of the dimeric forms of the E-s-E-s-trans and E-s-Z-s-trans conformers are higher than those of the monomers and are independent on total enaminoketone concentration. Addition of highly polar HMPA promotes proton transfer from nitrogen to oxygen in the Z-s-Z-s-trans isomer of 2 with subsequent isomerization into the linear imino-enol product but the rate constant of this transformation is ten-fold smaller than that for 1 in the Ar matrix exposed to UV radiation.

Thermal and Thermo-Oxidative Destruction of Poly(Ethylene Terephthalate) Modified with Formulation Based on Polyfluorinated Alcohol

Stabilizing effect of 1,1,9-trihydroperfl uorononanole-1 immobilized on a montmorillonite support on the stability of poly(ethylene terephthalate) at elevated temperatures was studied. Gas chromatography, IR Fourier spectroscopy, and mass spectrometry were used to examine gaseous products of its thermal and thermooxidative destruction. It was found that the initial formation rate of aldehydes and carbon dioxide decreases in the course of thermostating of the fl uorine-containing composite polyester material. The method of thermogravimetry demonstrated that modified poly(ethylene terephthalate) has a higher thermal stability.

Effect of the Addition of Silicon on the Properties of Germanium Single Crystals for IR Optics

Homogeneous Sb-doped single crystals of Ge–Si solid solutions are grown with a silicon content of 0.2 to 0.8 at %. The optical absorption of single crystals with a resistivity of (2–3) Ω cm is studied by IR Fourier spectroscopy at a wavelength of 10.6 μm in the temperature range from 25 to 60°C. It is found that the introduction of silicon into antimony-doped germanium improves the temperature stability of the optical properties of the crystals.

Thiocarbamoylation of Chlorosulfonated Polystyrene for Preparing Sorbents for Noble Metal Ions

A new sorbent for noble metal ions, ensuring selective recovery of Au(III) ions from aqueous solutions containing interfering 3d metal ions, was suggested. The new functional derivative, poly(thiocarbamoylsulfostyre ne), was prepared by treatment of poly(chlorosulfostyrene) with thiourea. At the total degree of functionalization with sulfo and thiourea groups of up to 1.0, the degree of thiocarbamoylation can be controlled in the range from 10 to 75%. The composition and structure of the polymer-analogous transformation products were characterized by elemental analysis, Fourier IR spectroscopy, and thermal gravimetric analysis with IR identification of the decomposition products. Evaluation of the sorption activity of poly(thiocarbamoylsulfostyrene) has shown that the sorbent takes up Au(III) ions virtually quantitatively with high selectivity from an aqueous solution containing Co(II), Fe(III), Pd(II), and Ni(II) ions.

Влияние добавок кремния на свойства монокристаллов германия для инфракрасной оптики

AbstractHomogeneous Sb-doped single crystals of Ge–Si solid solutions are grown with a silicon content of 0.2 to 0.8 at %. The optical absorption of single crystals with a resistivity of (2–3) Ω cm is studied by IR Fourier spectroscopy at a wavelength of 10.6 μm in the temperature range from 25 to 60°C. It is found that the introduction of silicon into antimony-doped germanium improves the temperature stability of the optical properties of the crystals.

The Production of Fluorine-Containing Composite Materials Based on Polydieneurethane and Montmorillonite

The effect of organomineral complexes of 1,1,3-trihydroperfluoropropanol-1 (modifier) with layered aluminosilicate montmorillonite (LAM) as filler on the structure and properties of fluorine-containing polydieneurethane (FPU) was investigated. The modifier and the LAM were introduced into the FPU at the stage of its production. Using a combination of methods – X-ray diffraction analysis (DRON-3), electron microscopy (Versa 3D DualBeam, USA), and Fourier IR spectroscopy (Nicolet-6700, USA) – we studied features of the layer separation of LAM in the elastomer matrix as a function of the modifier concentration. It was shown that FPU specimens filled with LAM containing 5.0% polyfluorinated alcohol disintegrate better and possess a higher resistance to thermooxidative ageing.

Interaction of Copper, Zinc, and Manganese Cations with Lignite and Humic Acids

By IR Fourier spectroscopy, EPR, and 13C NMR analysis in solids, the sorption of copper, zinc, and manganese cations by various materials from aqueous solutions is studied. The materials considered are Tyul’gansk lignite, Tisul’sk lignite in unoxidized and oxidized forms, humic acids, and the coal residues remaining after separation of the humic acids. The zinc cations are sorbed by ion exchange; copper and manganese cations are sorbed by a mixed mechanism: ion exchange and complex formation. All the samples are selective in terms of sorption of the cations: Cu2+ > Zn2+ > Mn2+.

Peculiarities of the composition of solid phases formed in aqueous calcium–silicate systems with a medium of variable acidity

The effect of a medium’s acidity on the composition of the solid phase formed in aqueous calcium-silicate systems is investigated. Solutions of Са(NO3)2 and Na2SiO3 are used for the synthesis; the pH values were varied in the range 7.00–12.00. Freshly precipitated solid phases and products of their annealing at 1000°C were studied by the methods of Fourier IR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM).

Antiturbulent properties of sulfomethylated polyacrylamide under the conditions of thermal, salt, and acid aggressions

Nonionic polyacrylamide with the weight-average molecular mass of 7 MDa was modified by sulfomethylation. The composition of sulfomethylated polyacrylamides was determined by iodometric titration, Fourier IR spectroscopy, thermal gravimetric analysis, and elemental analysis. The sulfomethylated acrylate polymers containing ≥19.9 mol % sulfo groups are resistant to brines containing up to 70 g L–1 CaCl2 at temperatures of up to 140°С and to hydrothermal treatment at 180°С. As shown by capillary turbulent rheometry under the conditions of thermal, salt, and acid aggressions, at the optimum concentrations of sulfomethylated polyacrylamide in the medium, с opt = 0.025–0.085%, the maximal extent of a decrease in the hydrodynamic resistance, DRmax, remains on the level of 71–80%, and the flow rate increment, ΔQ, is on the level of (22.01–28.85) × 10–6 m3 s–1.

Relationship between the morphology and combustibility of fluorinated polyamide composites

The effect that polyfluorinated alcohols immobilized on montmorillonite support exert on structuralmorphological characteristics and combustibility of polymer composites was studied with 1,1,9-trihydroperfluoro- 1-nonanol as example. The relationship between the flame resistance of this heterochain polymer and its morphology was revealed by X-ray diffraction analysis, electron microscopy, DSC, and Fourier IR spectroscopy. This relationship is associated with the reorganization of the crystal and molecular structure under the influence of fluorinated organoclay, ensuring increased degree of crystallinity and redistribution of the fractions of α- and γ-crystalline forms in the polymorphic composition of polycaprolactam, making its supramolecular structure more perfect, and favoring preparation of a fluorinated material of decreased combustibility.

Separating excess surfactant from silver and gold nanoparticles in micellar concentrates by means of nonaqueous electrophoresis

It is shown by physicochemical means (IR Fourier spectroscopy, CHN-analysis with preliminary sorption of surfactant on SiO2) that the content of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in an electrophoretic concentrate remains unchanged during the electrophoretic concentration of silver and gold nanoparticles. Diluting the concentrate and carrying out the second stage of electrophoresis reduces the concentration of surfactant from 0.25 to 0.015 M while maintaining the mass concentration of nanoparticles. Nanoparticles in organosols before and after electrophoresis are characterized by means of photon correlation spectroscopy, phase analysis light scattering, and spectrophotometry. Conducting films on glass substrates are obtained from concentrates with a different contents of surfactant via water–alcohol treatment and thermolysis.