Chain Macromolecules Research Articles

How specific ion effects influence the mechanical behaviors of amide macromolecules? A cross-scale study.

The mechanisms of specific ion effects on the properties of amide macromolecules is essential to understanding the evolution of life. Because most biological macromolecules contain both complex hydrophilic and hydrophobic structures, it is challenging to accurately identify the contributions of molecular structure to macroscopic behaviors. Herein, we investigated the influence of specific ion effects on the mechanical behaviors of poly(N-isopropylacrylamide) and neutral polyacrylamide (i.e., PNIPAM and NPAM), through a cross-scale study that includes single-molecule force spectroscopy, molecular dynamics simulation and macro mechanical method. The results indicate that the molecular conformation can be markedly influenced by the hydrophilicity (or hydrophobicity) of both macromolecule chain and ions. An extended chain conformation can be obtained when the side groups and ions are relatively hydrophilic, which can also increase the elasticity of a macromolecule chain and film materials. The relatively hydrophobic components promote the collapse of macromolecule chains and reduce the molecular elasticity. It is believed that the hydrogen bonding intensity between a macromolecule chain and aquated ions controls the chain conformation and the elasticity of molecules and films. This study is not only helpful for understanding the self-assembly mechanism of organisms but also provides a way to associate the molecular properties with the macroscopic performance of materials.

Aquasomes: A Promising Delivery Systems for Poorly Soluble Bioactives

Aquasomes are considered an excellent and efficient carrier system for the transport of drugs or biochemically active long chain macromolecules such as proteins and peptides, various hormones, antigens, enzymes, and genes in the recently burgeoning field of nanobiotechnology research. These are three-layer self-collecting structures composed of an oligomeric film covering a strong stage nanocrystalline centre to which biochemically dynamic particles adhere to, independent of changes in the environment and which self-assembles through non-covalent or ionic connections. Aquasomes are circular particles, 60–300 nm in size, that are used to deliver antigens and medications. The structural stability is provided by the solid core, while the active drug molecules are stabilized and protected from dehydration by the polyhydroxy oligomer covering. The most common way to distribute aquasome formulations is parenterally, however recent research indicates that there may be additional, oral, ways as well. A combination of targeted molecular shielding and prolonged release mechanism is used by aquasome to deliver their bioactive chemicals. The present paper offers an overview of the aquasome as a potentially useful medication delivery technique. It covers every facet of aquasome, such as their structure, the processes for preparing them, ways to characterize them, and medical uses as a drug delivery system.

Entanglements of Macromolecules and Their Influence on Rheological and Mechanical Properties of Polymers.

Flexible macromolecules easily become entangled with neighboring macromolecules. The resulting network determines many polymer properties, including rheological and mechanical properties. Therefore, a number of experimental and modeling studies were performed to describe the relationship between the degree of entanglement of macromolecules and polymer properties. The introduction presents general information about the entanglements of macromolecule chains, collected on the basis of studies of equilibrium entangled polymers. It is also shown how the density of entanglements can be reduced. The second chapter presents experiments and models leading to the description of the movement of a single macromolecule. The next part of the text discusses how the rheological properties change after partial disentangling of the polymer. The results on the influence of the degree of chain entanglement on mechanical properties are presented.

Investigation of the kinetics of heat treatment of epoxy polymers

The study examines the effect of the concentration of modifiers (BDI) on the annihilation characteristics of cured epoxy polymers using the positron annihilation method. The results show that both the concentration and size of microcavity defects decrease, which can be explained by the formation of densely sewn areas due to the production of additional bridges. The supramolecular structure of the formed epoxy polymer is discussed, with the identification of several distinct areas, including polymer globules formed by stacking chains of simple polyester macromolecules around polymerization centers, and the interglobular space consisting of the ends of macro chains and low molecular weight products. The end groups of polymerization-cured epoxy polymers, such as double bonds of the vinylidene type, hydroxyl and unreacted epoxy groups, create conditions for the splitting of BDI in the interglobular space. The study also demonstrates that at optimal concentrations of modifiers, there is a decrease in the radius and concentration of micropore defects, as well as a general decrease in the proportion of free volume. The curing processes of epoxy polymers and their heat treatment in the presence of modifiers are investigated, with BDI having a significant effect on the formation of the epoxy polymer structure.

Progress in Studies of Disentangled Polymers and Composites

Macromolecule entanglements are common in polymers. The first part of this review describes their influence on the properties of entangled polymers. Then, methods for reducing the entanglement density of macromolecule chains are discussed. It has been shown that research on partially disentangled polymers has provided a lot of new information about the relationship between the entangled state and properties of polymers. This research concerns, among others, mechanical and thermal properties and the crystallization process. A special disentangled polymer case, ultra-high-molecular-weight polyethylene, is also discussed. The results of research on polymer composites in which macromolecules were disentangled via processing and composites were produced using already disentangled polymers are presented in particular detail. It has been indicated that such composites and blends of disentangled polymers are promising and will probably be intensively researched in the near future.

Crystallizing Self-Standing Covalent Organic Framework Membranes for Ultrafast Proton Transport in Flow Batteries.

Covalent organic frameworks (COFs) display great potential to be assembled into proton conductive membranes for their uniform and controllable pore structure, yet constructing self-standing COF membrane with high crystallinity to fully exploit their ordered crystalline channels for efficient ionic conduction remains a great challenge. Here, a macromolecular-mediated crystallization strategy is designed to manipulate the crystallization of self-standing COF membrane, where the -SO3 H groups in introduced sulfonated macromolecule chains function as the sites to interact with the precursors of COF and thus offer long-range ordered template for membrane crystallization. The optimized self-standing COF membrane composed of highly-ordered nanopores exhibits high proton conductivity (75 mS cm-1 at 100 % relative humidity and 20 °C) and excellent flow battery performance, outperforming Nafion 212 and reported membranes. Meanwhile, the long-term run of membrane is achieved with the help of the anchoring effect of flexible macromolecule chains. Our work provides inspiration to design self-standing COF membranes with ordered channels for permselective application.

Crystallizing Self‐Standing Covalent Organic Framework Membranes for Ultrafast Proton Transport in Flow Batteries

AbstractCovalent organic frameworks (COFs) display great potential to be assembled into proton conductive membranes for their uniform and controllable pore structure, yet constructing self‐standing COF membrane with high crystallinity to fully exploit their ordered crystalline channels for efficient ionic conduction remains a great challenge. Here, a macromolecular‐mediated crystallization strategy is designed to manipulate the crystallization of self‐standing COF membrane, where the −SO3H groups in introduced sulfonated macromolecule chains function as the sites to interact with the precursors of COF and thus offer long‐range ordered template for membrane crystallization. The optimized self‐standing COF membrane composed of highly‐ordered nanopores exhibits high proton conductivity (75 mS cm−1 at 100 % relative humidity and 20 °C) and excellent flow battery performance, outperforming Nafion 212 and reported membranes. Meanwhile, the long‐term run of membrane is achieved with the help of the anchoring effect of flexible macromolecule chains. Our work provides inspiration to design self‐standing COF membranes with ordered channels for permselective application.

Chemorheology of a Si/Al > 3 Alkali Activated Metakaolin Paste through Parallel Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA).

Although geopolymers, as structural materials, should have superior engineering properties than traditional cementitious materials, they often need to improve their final characteristics' reproducibility due to the need for more control of the complex silico-aluminate decomposition and polymerisation stages. Thermosetting of a reactive geopolymeric paste involves tetrahedral Silicate and Aluminate precursor condensation into polyfunctional oligomers of progressively higher molecular weight, transforming the initial liquid into a gel and a structural solid. Viscosity and gelation control become particularly critical when the geopolymer is processed with 3D printing additive technology. Its physical state modification kinetics should match the flow and setting characteristics required by the deposition process. The reaction kinetics and the elastic and viscous characteristics preceding gelation and hardening have been investigated for an alkali-activated Metakaolin/Sodium Silicate-Sodium Hydroxide paste with a Si/Al ratio > 3. A chemoreological approach has been extended to these inorganic polymerisable systems, as already utilised for organic thermosetting polymers. Differential scanning calorimetry and Oscillatory DMA were carried out to monitor the advancement of the polymerisation reaction and the associated variations of the rheological viscoelastic properties. Dynamic thermal scans were run at 1 °C/min and a frequency of 10 Hz for the dynamic mechanical tests. The observed kinetics of polymerisation and variations of the elastic and viscous components of the complex viscosities and shear moduli are described in terms of polycondensation of linear and branched chains of oligomeric macromolecules of increasing complexity and molecular weight up to gelation (Gel1) and cross-linking of the gelled macrostructure (Gel2) and final glassy state. Geopolymerization can be allocated into two main behavioural zones: a viscoelastic liquid paste below 32.5% of reaction advancement and a viscoelastic solid above. Initial complex viscosities range from 2.3 ± 0.9 × 10-5 MPa*s to 6.8 ± 0.9 × 10-2 in the liquid-like state and from 1.9 ± 0.1 MPa to 9.6 ± 2.1 × 102 MPa in the solid-like state.

On the Influence of Counter-Ion Nature on Properties of Perfluorosulfonic Acid Membranes with Long and Short Side Chain

In this work, the study of water uptake, ionic conductivity, and Donnan potential in systems with perfluorosulfonic acid membranes in H+, Li+, Na+, and K+ forms and solutions of inorganic electrolytes is presented. The properties of the commercial Aquivion E87-05S and Nafion 212 membranes, as well as the membranes prepared from the dispersions of Nafion 212 in the solvents of different nature (N,N-dimethylformamide, 1‑methyl-2-pyrrolidone, isopropyl alcohol–water mixtures in volume ratio of 80–20) were investigated. The influence of the number of functional groups, the length of the side chains of the polymer macromolecules, and the polymer morphology in the membranes on their equilibrium and transport properties depending on the counter-ion nature was revealed. The effect of the relaxation and electrophoretic factors on the alkali metal ion transfer through the system of pores and channels of the perfluorosulfonic acid membranes was discussed. The slope of the concentration dependencies of the Donnan potential for all highly hydrated membranes in the H+ form was close to the Nernstian one, while the selectivity to the alkali metal ions increased for the membranes with the highest ion-exchange capacity or the lowest amount of sorbed water and diffusion permeability due to the exclusion of the co-ions from the membrane phase.

Crosslinking two-dimensional metalloporphyrin (Me-TCPP) nanosheet with poly(ethylene) glycol semi-interpenetrating polymer network for ultrahigh CO2/N2 separation selectivity via “rubber-band” straightening effect

To efficient separate carbon dioxide from power plant flue gas, three two-dimensional (2D) metalloporphyrin (Me-TCPP) nanosheets, Zn-TCPP, Cu-TCPP, and Ni-TCPP are crosslinked with poly(ethylene) glycol (PEO) semi-interpenetrating polymer via “rubber-band” straightening effect. Dispersion-corrected periodic density functional (DFT-D2) calculation reveals that the lowest N4-Metalδ+···Oδ− distance (2.81 Å) and the highest binding energy (19.9 kJ mol−1) are obtained between CO2 molecule and metalloporphyrin center (Zn–N4), as well as the lowest O4-Metalδ+···Oδ− distance (4.68 Å) and the highest binding energy (18.8 kJ mol−1) on metal cluster (Zn–O4). The 2D Zn-TCPP nanosheet with the strongest affinity toward CO2 molecule generates Zn2+-CO2 complex to remarkably boost CO2 solubility in mixed matrix membrane (MMMs). Thus, 2.5 wt% Zn-TCPP nanosheet incorporated PEO-based MMMs dramatically promotes CO2 permeability to 198 Barrers and ultrahigh CO2/N2 selectivity to 81. A novel “rubber-band” straightening effect is found and verified, which is induced by abundant interfacial coordination bonds between metal ions in nanosheets and ester groups (O–CO) in PEO polymer chains, the strong Me–O–CO interaction sites hold polymer chains and lead to their regular rearrangement. Owing to the abundant PEG groups in PEGMEA macromolecule chains, incorporating 1 wt% Zn-TCPP nanosheet into crosslinked XLPEGDAcoPEGMEA polymer achieves the highest CO2 permeability of 398 Barrers.

Screening of carboxylated nanodiamonds interactions with porcine gastric mucin and its methacryloyl derivative

The present study aims at screening the interactions of carboxylated nanodiamonds with porcine gastric mucin and its methacryloyl derivative, respectively. As resulted from QCM-D analyses, stable interactions took place between nanodiamonds and both glycoproteins. The increasing dissipation curves recorded when nanodiamonds are perfused onto the protein layer suggest a possible rearrangement of macromolecule chains into a looser network. Nanodiamonds do not lead to protein denaturation but induce a slight rearrangement of the polypeptide chains in terms of folding. Results suggest that stronger interaction took place between nanodiamonds and the pristine protein, when compared to the modified protein probably due to the larger number of available sites for H bonds.

Study of radical polymerization of diallyl monomer based on allyl bromide and piperidine

In this article, kinetic feature of N, N-diallylpiperidine bromide radical polymerization is investigated. Orders of reaction are determined by the monomer and by the initiator. Essential value in this regard acquire investigation of implementation mechanism on elementary acts of radical polymerization N-alkyl - N, N-diallylamines and their proton salts at initial extents of transformation in water and water-organic solutions. Specific cyclolinear polymerization of diallyl monomers salt allows excluding the act degraded transfer of the chain on monomer and gives the chance of receiving polymers with high molecular weight. Data of kinetic researches testify the lack of degradation inherent chain transfer. It is noted that polymerization rate decreases while adding monomer ethanol to water solution. NMR 13C-spectroscopic researches of the polymers received by radical polymerization of N, N-diallylpiperidine bromide testifies the existence in chains of macromolecules as to five - (48%), and six-membered cycles (52%) which are calculated from a ratio of intensity of signals of the corresponding carbon atoms. The combination of polymeric, surface active and electrolytic properties of the synthesized polymer leads to the new qualitative state possessing a number of specific features shown in conformational and electrochemical behavior of polymer solution. Finding these properties will cause assessment opportunities of synthesized polymer usage as cationic flocculants, coagulants, precipitators and other purposes. Therefore, as distinct from anion and nonionic flocculants, cationic flocculants show high efficiency on application of them for extraction of organic and colloidal pollution and sedimentation of the weighed particles. Besides big advantage of cationic flocculants is the absence of their corrosion action on metals.

Multifunctional modifier for regulating the properties of concrete mixtures

The purpose of this work is the synthesis of new highmolecular surfactants polyalkylacrylates and the establishment of correlations between their colloidal chemical properties. Well-known methods for the synthesis and determination of the properties of surfactants were used. New high molecular surface-active substances (HMSAS) were obtained based on the reaction of polymer-analogous transformations. The resulting copolymers contain side hydrocarbon radicals of various lengths. Polyalkylacrylates were obtained by esterification with aliphatic alcohols (butyl, octyl, decyl) in a mixture of organic solvents and the presence of a catalyst, sulfuric acid. The surface activity and foaming ability of the obtained new HMSAS in aqueous solutions have been studied. The results obtained showed that with an increase in the length of the aliphatic hydrocarbon radical in the chain of macromolecules, the surface activity of polyalkylacrylates increases. An analysis of the results showed a good correlation between foaming and surface activity of the investigated HMSAS. Based on research, it was found that the stability of the foams is largely determined by the interaction of the HMSAS molecules in the monolayer.

Физико-химические и термические превращения газонаполненной полимерной теплоизоляции естественного старения

Introduction. In the process of operation, various materials are subjected to prolonged exposure to environmental factors, which can lead to irreversible physical and chemical changes that affect not only their service life, but also fire safety. In this regard, the study of the influence of natural ageing on the features of the combustion process, fire hazard characteristics of thermal insulation materials is relevant. Aims and objectives. The aim of the work is to evaluate the physicochemical and thermal transformations of polymer gas-filled thermal insulation (expanded polystyrene foam) of long-term natural ageing. Methods. A set of physicochemical methods, namely X-ray phase analysis, infrared spectroscopy and thermal analysis methods (TG, DTG, DSC) were used to study the physicochemical nature and thermal stability of naturally aged polystyrene foam. Results and discussion. In the work the technical condition of polymer thermal insulation was assessed on the objects: cinema "Udarnik" (Russia, Moscow), 1927-1930 year of construction and a residential building (Tajikistan, Vahdat), 2014 year of construction. The method of X-ray phase analysis for polystyrene foam of natural ageing revealed a decrease in crystallinity. The change in the phase state of polymer thermal insulation indicates the thermal fluctuation nature of the processes associated with its natural aging and leading to a change in the ordering of the arrangement of individual macromolecular sites of aromatic hydrocarbon. At the same time, under the conditions of natural ageing there is a decrease in the apparent density of polystyrene foam by 20-41 %. By method of infrared spectroscopy the greatest changes are established in areas of characteristic absorption bands 3057...2846 cm-1, and also 1500...1450 cm-1, that testifies to destabilisation of hydrocarbon chains of macromolecules of polystyrene foam of natural ageing. The character of thermo-destructive transformations is established for the investigated samples, the tendency of expansion of the main section (335...470 °С) in comparison with the samples without natural ageing (360...450 °С) is revealed. The identified features of physicochemical and thermal transformations of naturally aged polystyrene foam can lead to changes in the intensity of the combustion process and heat release. Conclusion. According to the results of the study it is established that in the process of natural ageing in gas-filled polymers irreversible physical and chemical changes occur under the influence of environmental factors. Deterioration of the technical condition of polymer thermal insulation during its operation can lead to changes in the characteristics of fire hazard, features of its combustion and heat release when exposed to fire. Keywords: thermal insulation; polymers; polystyrene foam; fire hazard; service life; natural ageing.

Формування глютинових біокомпозитних матеріалів, наповнених подрібненими стеблами зернових культур

The article presents an analysis of the influence of temperature-time parameters of heat treatment on the compressive strength of biocomposite materials, the compositions of which was dried to regulate the moisture content. The samples formed by pressing the prepared composition, based on an aqueous solution of glutin and chopped stalks of cereal crops with a fixed moisture content. Excess moisture content in the composition was reduced by processing in a thermal field at a temperature of 50…60 °C for 20…30 minutes. The main heat treatment was performed for the pressed composition in a press form with fixed fastening of punches to avoid elastic aftereffect. The heat treatment temperature was 150 °C, the exposure time was 2 hours. After 1 hour, the biocomposite material additionally compressed to seal the porous structure formed as a result of water evaporation under the influence of a thermal field. Biocomposite materials with additional heat treatment at a temperature of 50 °C for 4 hours have the highest compressive strength. Under this mode of heat treatment, water molecules slowly evaporate and a rigid framework of the biopolymer matrix with the maximum number of physical and chemical bonds between the components is formed. Increasing the temperature of additional heat treatment to 100 °C and reducing the exposure time to 3 hours reduces the compressive strength of biocomposites due to the deformation of macromolecule chains of the biopolymer matrix and the partial destruction of physicochemical bonds. It is expedient to use the developed biocomposite materials for the manufacture of packaging elements and containers.

Construction of multiresponsive supramacromolecular hydrogels with a novel azobenzene derivative as crosslinkers

Supramacromolecular hydrogels (SMHGs) are attractive materials in various areas. Due to their excellent reversible photoisomerization ability, azobenzene derivatives have been widely applied to construct SMHGs. But the majority of these systems were realized only by transplanting azobenzene function groups into macromolecule chains, while low-molecular-weight (LMW) azobenzene derivatives are fairly rare. Therefore, it is highly desirable to develop facile and effective strategies for the construction of SMHG. Here, a new ABA-typed azobenzene derivative (AD) has been designed and synthesized, which can be applied as LMW crosslinkers to construct SMHGs through electrostatic interactions between AD and sodium alginate (SA). When AD is mixed with SA solution in acidic conditions, SMHGs can form at various concentrations of SA. In addition, the concentration of AD also has a large impact on the moduli values. Profiting from electrostatic interactions between AD and SA, as well as interchain hydrogen bonds of SA, SMHGs can experience sol-gel transitions under pH-, photo- or thermo-stimuli. This work contributes a simple but effective strategy for the construction of SMHGs using azobenzene derivatives as LMW crosslinkers.

Electrospun Lignin-Based Phase-Change Nanofiber Films for Solar Energy Storage

Functional materials for solar energy collection, conversion, and storage need to be developed to address the global energy crisis. In this study, phase-change nanofiber films [PCNFs, sodium lignosulfonate (SLS)/polyvinyl alcohol (PVA)/polyethylene glycol (PEG)], which maintain their shape, were developed for solar-to-thermal energy conversion and storage. The films were constructed by electrospinning with PEG as the phase-change material, SLS/PVA mixture as the supporting matrix, and SLS as the photothermal material. SLS effectively improved the supporting property of the PCNFs owing to sturdy hydrogen bonds and electrostatic entanglement between its macromolecule chains and PVA/PEG, which prevented the leakage and transfer issue for PEG. Moreover, the PCNFs showed excellent solar-to-thermal energy conversion and storage ability, attributed to the π–π stacking of SLS molecules and the phase-change process, respectively. The SLS/PVA/PEG film with a PEG content of 32.43% exhibited a diameter of 465 ± 109 nm and a latent heat of fusion of 42.16 J·g–1, with a phase-change temperature of 45.20 °C. The film showed favorable stability over 50 heating–cooling cycles, thermal stability below 220 °C, good shape stability, and a solar-thermal energy conversion and storage efficiency of 18.03%. This study demonstrates a potential route to improve the utilization of lignin and solar energy and promotes the development of sustainable energy.

Effect of fique fibers and its processing by-products on morphology, thermal and mechanical properties of epoxy based biocomposites

This work examines the morphology, mechanical and thermal properties of biocomposites based on epoxy resin-EP and fique (Furcraea andina), a native crop of South America. The EP-fique biocomposites were prepared using fique powder-FP an industrial waste generated during fique processing, nonwoven fique fiber mats-NWF and unidirectional fique fiber mats-UF oriented at 0° and 90°. The addition of fique into EP matrix restricts EP macromolecule chains movement and enhance the thermal stability of EP. SEM images showed that fique form used (powder or fiber) and mat arrangement can generate changes in the biocomposites morphology. Mechanical characterization show that fique powder and fique fibers oriented at 90° acts as fillers for the epoxy matrix while the fique fibers oriented at 0° reinforce EP matrix increasing the tensile and flexural modulus up to 5700 and 1100% respectively and tensile and flexural strength up to 277% and 820% in comparison with neat EP. The obtained results can increase the interest in researching and developing products from fique Powders and other natural fibers processing byproducts thus reducing the abundance of waste in soil and landfills and environmental concerns and suggest that the EP-fique biocomposites are promising to be used in the automotive sector.

AN OVERVIEW ON AQUASOMES : A NOVEL APPROACH FOR DELIVERING MACROMOLECULES

In recent blossoming era of research in nanobiotechnology, aquasomes are viewed as an effective and efficient carrier system for drug delivery or biochemically active long chain macromolecules like protein and peptide, different hormones, antigens, enzymes and gene delivery. Aquatones are spherical in shape and having particle size within 60- 300nm. Self-assembled structure of aquasome (due to its natural property) it generates a focus on nanobiotechnology research as a carrier system. Mainly, aquasomes contain three-layers, that is core material, coating material, drug layer attached by ionic or non-covalent bond. Aquasomes include mainly the core materials like , hydroxyapatite, solid phase nanocrystalline ceramic diamond (carbon) and calcium phosphate dihydrate(brushite) . The coating of core material is done with glassy polyhydroxyl oligomeric film such as cellobiose and trehalose, on which modification of biochemically active molecules are attached. Whereas, calcium phosphate used as a core material, because of it is naturally present in the body. Whether calcium phosphate is unstable in nature, due to prolong storage it converts into hydroxyapatite which is a better core than calcium phosphate to develop the aquasomes. The solid core material renders stability of structures, while the coating material stabilizes the biochemically active molecules and protects against dehydration. In this review, we tried to an overview of aquasomes, and about its advantages over conventional drug delivery system, shielding effect of aquasomes on desired drug and how its self-assembled structures, makes them an attractive carrier to deliver biochemically active molecules.

Study of the fibrinogen structure by the method of small-angle synchrotron scattering

Fibrinogen is synthesized by human liver cells and is constantly present in the blood. Protein is the main factor of blood clotting and largely determines the blood viscosity. Any damage to a blood vessel or tissue in the body triggers hemostasis (blood clotting). Fibrinogen under the action of thrombin is converted into fibrin, an insoluble biopolymer, which is the basis of a blood clot that provides hemostasis. Apart of wound healing, fibrinogen is involved in the pathogenesis of malignant neoplasms. Fibrinogen labeled with 125I is used to diagnose thrombosis because it penetrates blood clots. We present the results of studying the structure of fibrinogen in human blood plasma using small-angle X-ray scattering (SAX). The SAX method, widely used in analysis of supra-atomic structures of substances, provides determination of the size of domains present in proteins, their shape, as well as the conformation of segments of chain macromolecules in the form of Gaussian and persistent chains. An important feature of the method is the possibility of studying biological objects in their natural state, without any special pretreatment. It is shown that globular domains of two sizes (diameters — 8.4 and 4 nm, respectively) are present in the structure of fibrinogen. The domains are coupled by polypeptide chains (α, β, γ) twisted in the form of spiral coils. The stiffness of the chains estimated as a persistent length was 3.1. The results obtained can be used in surgical practice and replacement therapy when creating fibrin glue as a hemostatic drug that stops bleeding with minimal invasiveness of intervention, and drugs that eliminate fibrinogen deficiency in the blood.