Nina Kotelnikova

Full text is available here: https://rdcu.be/d4rIM Objective: This study aimed to synthesize and characterize hybrid nanocomposites of powder celluloses (PCs) derived from waste newsprint and cardboard, incorporating silver nanoparticles. The focus was on the mechanism of nanoparticle formation and stabilization within the cellulose matrix during...

The full text is available https://rdcu.be/dusXY. A comparative study of the supramolecular structure, physicochemical properties, and morphology of the powder celluloses (PCs) obtained from the waste paper of newsprint and cardboard, plant celluloses, and nonconventional raw materials was conducted using the methods of FT-IR spectroscopy, high-re...

Two-phase hybrid hydrogels from powder cellulose (PC) and/or microcrystalline cellulose (MCC) and biologically active natural cyclic oligosaccharide β-cyclodextrin (β-CD) were obtained by combining them in the solvent N,N-dimethylacetamide/LiCl and regenerating the hydrogels from the solutions. Cellulose-cyclodextrin hybrid hydrogels were synthesiz...

Hybrid nanocomposites of powder celluloses (PCs) isolated from newsprint and cardboard waste containing silver nanoparticles (NPs) were synthesized using the diffusion-reduction method. The reduction of silver from solutions of its salt was carried out under heterogeneous conditions using trisodium citrate as a reducer. Molar ratio (MR) of PC/silve...

Cellulose is the most abundant natural polymer that is of particular interest for processing due to its unique properties: biodegradability, biocompatibility, and ubiquitous availability. New functional materials, including hydrogels, can be produced from cellulose. The hydrogels are super-swollen systems with a three-dimensional polymer framework....

A comparative study of the supramolecular structure, physico-chemical properties and morphology of powder celluloses (PCs) obtained from the waste paper of newsprint and cardboard, plant cellulose and unconventional raw materials was conducted using the methods of FTIR spectroscopy, high-resolution 13C NMR spectroscopy in the solid phase, wide-angl...

The morphology of hydrogels regenerated from solutions of waste paper and cardboard in DMAс/LiCl was studied for the first time in comparison with the morphology of pristine samples and powder celluloses isolated from waste paper. Two sets consisted every of them from 4 samples, pristine waste paper or cardboard, powder cellulose, swollen hydrogel...

An efficient process for recycling paper and cardboard wastes via dissolution in N,N-dimethylacetamide/lithium chloride (DMAc/LiCl) system and regeneration from solutions to obtain hydrogels has been developed. Pretreatment of waste paper has been carried out by thermal defibrillation of waste paper in water and homogenization to obtain fibre sampl...

Waste management is one of the major aspects of sustainable development. World paper and board manufacturing is rapidly raising. Waste paper and biomass residues are rich but low-cost sources of cellulose for further processing. Since the environmental impact of paper is very high worldwide, it has led to the development of modern technologies. The...

Hybrid composite hydrogels were synthesized by immobilization of 1,10-phenanthrocyanine zinc(II) complex in cellulose hydrogels. The hydrogels exhibited long-term stability, high water retaining capacity and porosity, which were determined using chemical methods. They were characterized with wide-angle X-ray scattering (WAXS), Fourier transform inf...

Utilization of paper wastes as renewable resource of lignocellulosic constituents has the opportunity to promote a cleaner environment and to prepare valuable materials. This paper describes our study on an isolation of low-fiber powder cellulose from two grades of wastes as feedstocks: waste newsprint paper and cardboard wrapper through recycling...

New composites are obtained in the diffusion-adsorption immobilization of electron-excess zinc(II) 1,10-phenanthrocyanine complexes [(phen)nZn(μ-phencyanine)Zn(phen)n(OAc)4∙HOAc] (n = 0-2) in a 3D structure of super-swelling cellulose hydrogels. A mechanism is proposed for the immobilization of the zinc complexes in the hydrogel structure. The func...

Powder cellulose fibres and their hydrogels were used as matrices to synthesize hybrid biocomposites functionalized with zero-valent silver and gold nanoparticles. FTIR and X-ray spectroscopy, WAXS, and SEM were applied to study mechanism of metallization of these matrices and properties of the nanobiocomposites. Content of the embedded metals in t...

Cellulose powders from flax fiber and deciduous wood and hydrogels regenerated from DMA/LiCl solutions of them were studied using x-ray diffraction. Structural characteristics were calculated. Three-dimensional models of atomic positions in the short-range order of amorphous hydrogels were constructed. It was found that flax cellulose was character...

Super-swollen hydrogels were prepared in vitro from lignocelluloses of various origins via direct dissolving in N,N-dimethylacetamide/lithium chloride (DMAc/LiCl) followed by regeneration from solutions. The hydrogels retained a large amount of water (up to 2500 wt%) and had high porosity and specific surface areas. Superabsorbance of the hydrogels...

Получены образцы порошковых целлюлоз из макулатурной массы (ММ) отходов газетной бумаги и картона. Процесс переработки макулатуры состоял из предварительной обработки и кислотного гидролиза. Предварительную обработку проводили путем терморазволокнения ММ в воде, мацерации раствором NaOH и отбелки раствором Н2О2. В результате кислотного гидролиза пр...

The hybrid bionanocomposites of deciduous powder cellulose and hydrogels were prepared via reduction of silver ions with a trisodium citrate directly in the sample matrices. The materials containing silver nanoparticles were studied with a wide-angle X-ray scattering (WAXS). The maximum content of silver(0) reduced in the powder matrix was 4.8 mass...

The powder celluloses exposed to dissolving in DMAc/LiCl and subsequent regeneration from solutions as super-swollen hydrogels have changed their supramolecular structure from cellulose I to cellulose II.

Cellulose-based hydrogels have been prepared from solutions of hardwood and flax lignocelluloses and cotton cellulose in an N,N-dimethylacetamide–lithium chloride (DMAc/LiCl) mixture by regeneration and subsequent self-assembly of cellulose chains. The main physicochemical characteristics of the hydrogels have been investigated. It has been shown t...

Hydrogels of flax and hardwood pulp powders were prepared by regeneration from solutions in N,Ndimethylacetamide—LiCl. Silver (Ag) nanoparticles were intercalated into the pulp hydrogel matrices by reducing a solution of AgNO3 using trisodium citrate. The resulting samples were studied by wide-angle x-ray scattering, x-ray photoelectron spectroscop...

A comparative study on two methods for dissolving of powder lignocelluloses, derived from wood lignocelluloses and from short-length flax fibers, in DMAc/LiCl was carried out. It was shown that DPv values of the samples and lignin content significantly affected their solubility. The lower these values were, the better the solubility of the samples...

A component, chemical and morphological composition of wood of the Howea fosteriana palm and the Cereus peruvians cactus and the wood stem of the Dracaena sanderiana was studied. The supramolecular structure and the physicochemical properties of cellulose samples which were extracted from the wood species were examined by wide-angle X-ray scatterin...

Comparative study of two methods to dissolve powder lignocelluloses obtained from wood lignocelluloses and short flax fibres in DMAA LiCl was performed. DP values and lignin content in the samples significantly affect the solubility. The lower these values, the higher solubility of the samples. Solubility of the powder samples from wood lignocellul...

The solubility of powder lignocelluloses from flax wastes and wood pulps in the N, N-dimethylacetamide/lithium chloride (DMAc/LiCl) system was studied. The chemical "purity" and the degree of polymerization of the lignocelluloses mainly affected their dissolving capacity. Regenerated cellulose samples prepared by precipitating cellulose solutions w...

Methods of wide-angle X-ray scattering (WAXS), high resolution solid-state 13C NMR, and Fourier transform IR-spectroscopy are applied to study supermolecular structures and functional compositions of lignocellulose samples of wood and grass origins and powdered celluloses (PC) obtained from them under identical hydrolysis conditions. It was shown b...

Изучен компонентный, химический и морфологический составы древесины пальмы Howea fosteriana, кактуса Cereus Peruvians и стволовой части драцены Dracaena Sanderiana. С помощью методов широкоуглового рентгеновского рассеяния, ИК-Фурье спектроскопии, 13С ЯМР спектроскопии высокого разрешения в твердой фазе и сканирующей электронной микроскопии исследо...

Dissolution of powder cellulose samples from flax wastes and wood pulps in the dimethylacetamide-LiCl solvent was studied. The decisive factors of cellulose dissolution are the degree of chemical “purity” of cellulose and the degree of polymerization. The cellulose I supramolecular structure of the initial samples transforms into a mixture of polym...

This project studies the dependence of the physical and chemical properties of powdered cellulose on their natural origin and conditions of preparation. We studied the effect of chemical composition and properties of the original native cellulose on the general characteristics of the powdered and microcrystalline cellulose obtained from arboreal an...

Nanocomposite materials containing stabilized nickel nano- and microparticles in the matrix of the hydrate cellulose film (HCF) have been prepared. Ni nanoparticles were synthesized directly in the film, by the diffusion-reduction method. The efficiency of reducers on the chemical reduction of nickel ions has been compared. The crystalline structur...

Materials containing micro- and nanodisperse nickel particles in hydrated cellulose film have been obtained by diffusion reduction. The effect of various NaOH concentrations on the film structure, functional composition, and morphology; nickel ion reduction; and nanocomposite material formation has been studied by Fourier transform infrared spectro...

The properties and structure of a hydrate cellulose film have been studied by WAXS, FTIR spectroscopy, X-ray photoelectron spectroscopy, high-resolution 13C NMR spectroscopy in solid state, and scanning electron microscopy.

A detailed physico-chemical characterisation of potential new cellulose sources (rice husk, hemp stalk, and coniferous needles), and microcrystalline cellulose (MCC) manufactured from them, was made in this work. The length and the width of the cellulose crystallites were determined by wide-angle X-ray scattering (WAXS), crystallinities were studie...

The effects of different solvents on the structure of microcrystalline and nanofibrillated cellulose (MCC, NFC) were studied using small-angle x-ray scattering (SAXS). MCC was immersed in water, ethanol, and acetone, and NFC was immersed only in water and ethanol, but studied also in the form of foam-like water-NFC-gel in wet, air-dried and re-wet...

The formation of cellulose-nickel nanocomposites has been studied by WAXS, X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and scanning electron spectroscopy. Changes in the experimental conditions make it possible to widely vary the size of nickel and its oxide nanoparticles in the bulk and on the surface of cellulose fibers and t...

The structure of microcrystalline cellulose (MCC) made by mild acid hydrolysis from cotton linter, flax fibres and sulphite or kraft cooked wood pulp was studied and compared with the structure of the starting materials. Crystallinities and the length and the width of the cellulose crystallites were determined by wide-angle X-ray scattering and the...

In this study we used hydrate cellulose films for research of morphological and structural characteristics and as a matrix for intercalation of nickel particles. A method of nickel ion reduction from its salt and direct sedimentation of metal in the film was applied. A sodium tetraboronhydride (NaBH4) and potassium hypophosphite (КH2PO2•H2O) was us...

Polymeric matrices with stabilized metallic nanoparticles constitute an important class of nanostructured materials, because polymer technology allows fabrication of components with various electronic, magnetic and mechanical properties. The porous cellulose matrix has been shown to be a useful support material for platinum, palladium, silver, copp...

In last decade embedding of metallic phase to matrices of native polymers have been systematically studied in the Institute of Macromolecular Compounds of the Russian Academy of Sciences. Application of polymer matrices renewable in nature such as cellulose of various origins in solid state and its derivatives in solutions opens capacities to creat...

Copper and nickel nanoparticles were synthesized in the insoluble microcrystalline cellulose support by reduction of metal ions with several reducers in various media resulting in cellulose-metal nanocomposites. Wide-angle X-ray scattering results showed that supramolecular structure of cellulose did not change. Crystalline Cu2O and Cu0 nanoparticl...

Nickel nanoparticles were synthesized by adding aqueous nickel salt into a microcrystalline cellulose matrix. The Ni-II ions were reduced with either sodium borohydride, NaBH4, or potassium hypophosphite, KH2PO2, in water or aqueous NH3 medium. The mass fraction of Ni in the samples was between 3.7 and 8.9%. X-ray absorption spectra at the Ni K-edg...

Microcrystalline cellulose is a porous natural material which can be used both as a support for nanoparticles and as a reducer of metal ions. Cellulose supported nanoparticles can act as catalysts in many reactions. Cu, CuO, and Cu 2O particles were prepared in microcrystalline cellulose by adding a solution of copper salt to the insoluble cellulos...

Trypsin and α-chymotrypsin were immobilized on a microcrystalline cellulose matrix by their adsorption interaction with cellulose. Enzymes' adsorption has been determined as a function of enzymes' concentration and pH of their solutions. Enzymes' adsorption onto cellulose is a combination of physical adsorption and chemisorption. Desorption, FTIR a...

A matrix of microcrystalline cellulose was used as a nanoreactor for the reduction of Ni(II) ions with hydrazine dihydrochloride.

Trypsin and alpha-chymotrypsin were immobilized on a microcrystalline cellulose matrix by their adsorption interaction with cellulose. Enzymes' adsorption has been determined as a function of enzymes' concentration and pH of their solutions. Enzymes' adsorption onto cellulose is a combination of physical adsorption and chemisorption. Desorption, FT...

Comparison of some characteristics of microcrystalline cellulose samples and of those subjected to intercalation of silver (0) clusters using Raman spectroscopy and SEM combined with EDXA has been carried out. It has been shown that Raman spectroscopy is one of the most sensitive spectral methods to characterize the changes occurring in diffusion-r...

A novel path for the preparation of biologically active compounds (BAC) on the basis of natural polymer cellulose has been developed. Various types of cellulose, microcrystalline cellulose (MCC) included, have been used as matrices for the biologically active substances. Adsorption-desorption interaction of cellulose with surfactant antiseptics of...

Adsorption of trypsin to microcrystalline cellulose has been determined as functions of protein concentration and pH of the aqueous medium. The study of adsorption at several pH values indicates that interaction of trypsin to the microcrystalline cellulose interface is controlled by the electrostatic effect. The FTIR, desorption, and SEM data revea...

Preparation of microcrystalline cellulose-Ag n systems consists of two main stages: preliminary diffusion of Ag + ions from aqueous AgNO 3 solutions into the cellulose matrix and subsequent reduction of Ag + ions bound to the molecules of microcrystalline cellulose, with the formation of Ag n clusters intercalated into MCC. Different mechanisms in...

Diffusion of silver ions into a cellulose matrix and their subsequent reduction both with the matrix itself and with specific reducers lead to preparation of cellulose materials containing silver(0). Most silver metal is intercalated into the cellulose matrix when glycerol is used as solvent and potassium hypophosphite or sodium boron hydrate are u...

The preparation of microcrystalline cellulose samples containing intercalated silver(0) particles includes two main stages: diffusion of silver ions from aqueous AgNO3 into the microcrystalline cellulose matrix, followed by reduction of the silver ions bound to cellulose macromolecules to Ag(0) and growth of Ag(0) particles inside the cellulose mat...

Diffusion-reduction interaction between microcrystalline cellulose and aqueous solution of AgNO3 was studied in the absence (taking into account the reducing properties of cellulose) and in the presence of specific reductants. The resulting intercalates of cellulose and zero-valent silver were examined by raster and transmission electron microscopy...

Fibre morphological structure of microcrystalline cellulose samples and of those subjected to chemical treatments, in order to intercalate silver clusters into the cellulose matrix, was observed with raster and transmission electron microscopes. Samples' morphological parameters were characterised, permitting a comparative study of the examined spe...

Silver ions' diffusion into the microcrystalline cellulose matrix and its subsequent reduction by means of both reducing properties of the matrix itself and specific reducers gives cellulose materials containing silver with a degree of oxidation 0. The highest quantity of silver intercalation into the cellulose matrix is attained by using glycerol...

Preparation of new metallic derivatives of cellulose was discussed. Lithium and sodium derivatives of cellulose were prepared by treating microcrystalline cellulose with complexes of lithium or sodium with ethylenediamine (EDA) or with hexamethylphosphoramide (HMPT). The resulting compounds containing nitrogen (in the case of EDA) or nitrogen and p...

Adsorption of human serum albumin to microcrystalline cellulose interface has been determined as functions of protein concentration and pH of the aqueous solutions. The maximum adsorption value is reached at the protein isoelectric point. The study of adsorption at several values of pH indicates that its interaction with the MCC interface is not co...

Mechanism of diffusion-reduction interaction of silver(I) complexes containing biologically active heterocyclic ligand 1,10-phenanthroline with microcrystalline cellulose at cellulose/solvent interface in thermally activated reaction conditions was developed. The resulting compounds are of considerable interest for medical application.

A series of composites based on segmented polyurethanes (PU) as polymer matrices and natural polysaccharides – cellulose and starch – as fillers have been synthesized. Using IR method and Differential Scanning Calorimetry the peculiarities of the structure of composites and their behavior in the buffer solutions in conditions imitating natural soil...

Electrosurface characteristics (the exchange capacity and the electrokinetic potential) of the samples of cotton and wood microcrystalline celluloses (MCC) were studied as functions of the pH and the concentration of background electrolyte (10–3–1M NaCl). It was found that the MCC samples are negatively charged over the studied pH range (3.5–10.0)....

Crosslinked polymers containing starch have been used for the recovery of various pollutants from aqueous solutions. These polymers have been prepared by reticulation of starch-enriched flour using epichlorohydrin as crosslinking agent. Several studies (kinetics, time, concentration, role of crosslinking agent) are presented here. The results show...

Flax and cotton fibres were used as matrices for surfactant antiseptics with a wide spectrum of antimicrobial effect. These antiseptics are a complex of the copolymer of N-vinylpyrrolidone and crotonic acid with dimethylbenzylalkylammonium chloride and its low molecular weight analogue, dimethylbenzylalkylammonium chloride. Kinetic dependencies of...

Polyaniline (PANI) doped with different dopants (HCI, dodecyl benzene sulfonic acid, (+)-Camphor-10 sulfonic acid, dinonyl naphthalene disulfonic acid) was synthesized by chemical oxidation method. The FTIR studies indicated that the back bone structure of doped PANI was similar. Thermal stability was evaluated in nitrogen atmosphere by dynamic the...

Two types of standard flax fibres were analysed by chemical methods. Specific features of their supramolecular structure were studied by WAXS, IR and ¹³C NMR spectroscopy in solid state. Morphological structure of flax fibres was examined by SEM. One of the flax fibres has great natural pores and cavities that can lead to its high reactivity.

Dressing cellulose materials (CM) and bleached cotton cloth (cc) modified by surfactant antiseptics (CA) have been prepared by the method of adsorption interaction between CM and CA. Antiseptics release was studied by the method of desorption in solutions at different pH values. Maximum release of surfactants is achieved in solutions at pH = 7.0. M...

In order to obtain multicomponent polymer systems exhibiting biological activity, microcrystalline cellulose was used as a matrix for biologically active compounds, such as dimethylbenzylalkylammonium chloride, poly-N-vinylpyrrolidone, copolymer of N-vinylpyrrolidone and crotonic acid, and polymer complex of dimethylbenzylalkylammonium chloride wit...

In order to obtain multicomponent polymer systems exhibiting biological activity microcrystalline cellulose was used as a matrix for biologically active compounds, such as dimethylbenzylalkylammonium chloride, poly-N-vinylpyrrolidone, copolymer of N-vinylpyrrolidone and crotonic acid, and complex of dimethylbenzylalkylammonium chloride with copolym...

The WAXS, SAXS, SEM, TEM, XPS were used to study methods of platinum and palladium aggregates intercalation into the cellulose matrix and changes of cellulose structure after this intercalation. As a result new microcrystalline cellulose - metal compounds containing aggregates of platinum, and palladium were synthesised for the first time using the...

Adsorption interaction between Catapol, an antiseptic with a broad-spectrum activity, and samples of microcrystalline cellulose of various natural origins was studied. Similarities and differences in the kinetics of adsorption and desorption processes on samples obtained from cotton and wood cellulose as well as from bagasse and reed celluloses wer...

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Adsorption properties of dressing cellulose materials with respect to surfactant antiseptics were studied. These antiseptics are a complex of the copolymer of N-vinylpyrrolidone and crotonic acid with dimethylbenzylalkylammonium chloride (a synthetic polymer with a wide spectrum of antimicrobial effect) and its low molecular weight analogue (dimeth...

Cellulose substrates are increasingly used as supports and fillers in medicine, as membranes and components of organic sensors. In the present paper the WAXS as well as SEM, TEM, XRF, EDXA, ESCA, FTIR, Raman, and 13C NMR were used to study methods of metal clusters intercalation (taking as an example silver clusters) into the cellulose matrix and c...

Adsorption of polyvinylpyrrolidone on microcrystalline cellulose as influenced by the molecular mass of the former and concentration of aqueous solutions was studied. The adsorption of polyvinylpyrrolidone on the cellulose matrix is physical. It is determined by cooperative effects and is strongly influenced by the molecular mass of polyvinylpyrrol...

Potassium derivatives of cellulose were prepared by treating of microcrystalline cellulose (MCC) with complexes of potassium (K) with ethylenediamine (EDA) and K with hexamethylphosphoric triamide (HMPT). The reaction products were characterized by X-ray diffraction,13C-NMR and FTIR spectroscopy, SEM, and EDXA.

Lignincarbohydrate complexes (LCC) of poplar wood obtained by sulfate pulping and containing lignin in amounts of 0.9–8.3% have been studied by X-ray diffractometry. Heterogeneous hydrolysis methods have been used to determine their reactivity. The content of the crystalline fraction in LCC depends on the lignin removal and increases with the decre...

The influence of amorphous zones in cotton cellulose on its structural conversions in monoamine and diamine solutions was established using X-ray diffractometry. - Abstract Bulletin of the Institute of Paper Chemistry, 59(11), 1989, abstract 10813

The experiments on 45 inbred male and female rats with alloxan diabetes have shown that microcrystalline cellulose at a dose of 3 g/day received per os beginning from day 15 to day 42 after alloxan administration stabilizes the animals' body mass, reduces the level of glycemia and glycosylated hemoglobin. A parallel reduction of triglyceride and to...

The purpose of this work was to study interaction of cellulose with heterogeneous systems consisting of water, an acid, and an organic liquid insoluble in water, using the method of determination of the retention of the liquids by cellulose after centrifuging. Experiments show that the method of adsorption followed by forced desorption (in a centri...

Investigations of the heterogeneous and homogeneous degradation, reactivity and other properties of cellulose are generalized, and the properties of elements appearing after the degradation of native cellulose fibres are described in detail. On the basis of this generalization a model for the fine structure of native cellulose is proposed which agr...

The temperature-frequency dependence of the dielectric loss factor have been studied on wood and cotton cellulose samples in their original, micro-crystalline and amorphous states. Three dielectrically active relaxation processes can be observed on these samples and one structural-type transition; a molecular interpretation is given. A connection b...

Radiation-chemical processess involving cellulose are the subject of a considerable number of publications. However, this is still a subject of great interest both from the theoretical standpoint, e.g., for interpretation of solid-phase conversions and structure of cellulose, and for practical purposes, such as production of soluble degraded cellul...

The mechanical and chemical degradation of cotton and wood cellulose in organic swelling agents and hydrochloric acid was studied in an apparatus creating shear stress. The degree of cellulose degradation was greater in non-miscible solvents than in water-miscible solvents. The cellulose became more amorphous in the alcohols but not in the other so...