Polymer Coatings Research Articles

Biofilm morphology and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) on poly-D,L-lactide-co-poly(ethylene glycol) (PDLLA-PEG) coated titanium

Biodegradable polymeric coatings are being explored as a preventive strategy for orthopaedic device-related infection. In this study, titanium surfaces (Ti) were coated with poly-D,L-lactide (PDLLA, (P)), polyethylene-glycol poly-D,L-lactide (PEGylated-PDLLA, (PP20)), or multi-layered PEGylated-PDLLA (M), with or without 1 % silver sulfadiazine. The aim was to evaluate their cytocompatibility, resistance to Staphylococcus aureus biofilm formation, and their potential to enhance the susceptibility of any biofilm formed to antibiotics. Using automated high-content screening confocal microscopy, biofilm formation of a clinical methicillin-resistant Staphylococcus aureus (MRSA) isolate expressing GFP was quantified, along with isogenic mutants that were unable to form polysaccharidic or proteinaceous biofilm matrices. The results showed that PEGylated-PDLLA coatings exhibited significant antibiofilm properties, with M showing the highest effect. This inhibitory effect was stronger in S. aureus biofilms with a matrix composed of proteins compared to those with an exopolysaccharide (PIA) biofilm matrix. Our data suggest that the antibiofilm effect may have been due to (i) inhibition of the initial attachment through microbial surface components recognising adhesive matrix molecules (MSCRAMMs), since PEG reduces protein surface adsorption via surface hydration layer and steric repulsion; and (ii) mechanical disaggregation and dispersal of microcolonies due to the bioresorbable/degradable nature of the polymers, which undergo hydration and hydrolysis over time. The disruption of biofilm morphology by the PDLLA-PEG co-polymers increased S. aureus susceptibility to antibiotics like rifampicin and fusidic acid. Adding 1 % AgSD provided additional early bactericidal effects on both biofilm and planktonic S. aureus. Additionally, the coatings were cytocompatible with immune cells, indicating their potential to enhance bacterial clearance and reduce bacterial colonisation of titanium-based orthopaedic biomaterials.

Icephobic Gradient Polymer Coatings Coupled with Electromechanical De‐icing Systems: A Promising Ice Repellent Hybrid System

Icephobic Gradient Polymer Coatings Coupled with Electromechanical De‐icing Systems: A Promising Ice Repellent Hybrid System

Safety and efficacy of coated flow diverters in the treatment of cerebral aneurysms during single antiplatelet therapy: A multicenter study.

This multicenter study evaluates the safety and efficacy of coated flow diverters (cFDs) for the treatment of cerebral aneurysms under single antiplatelet therapy (SAPT). This is a retrospective, observational study of 41 patients (median age: 58 years) with 41 aneurysms (median size: 7 mm, 29 [71%] saccular, 9 [22%] ruptured) treated with cFDs at four neurovascular centers between 2020 and 2023. Scheduled cases received continuous SAPT starting seven days before the procedure. Emergency cases were treated with tirofiban followed by SAPT loading. The safety endpoint was ischemic complications occurring during the procedure and within four months of clinical follow-up. The Pipeline Vantage or Flex Shield was used in 26 (63%) procedures, the FRED X in 12 (29%), the p48/64 Hydrophilic Polymer Coating in 2 (5%), and the Derivo Embolization Device 2heal in 1 (2%). Single antiplatelet therapy consisted of prasugrel in 27 (66%) patients, ticagrelor in 9 (22%), and ASA in 5 (12%). There were 2 (5%) early ischemic complications (one minor stroke and one transient ischemic attack). There were no late ischemic complications in the four-month follow-up of 35 patients. The six dropouts included four nontreatment-related deaths after subarachnoid hemorrhage and two patients with a poor outcome after subarachnoid hemorrhage. Complete and favorable occlusion rates (median: 7 months) were 75% (27/36) and 89% (32/36), respectively. Coated flow diverter implantation in the setting of SAPT was safe and effective and warrants confirmation in a prospective comparative trial.

B-037 Zeon original coating technology COP microplates for cell imaging

Abstract Background Zeon has developed high quality microplate made of Cyclo Olefin Polymer (COP) and special coat reagent for cell culture for Aurora microplates. The new 96 well-microplates have best-in-class properties for analysis of cultured cells can reduce the background of fluorescence images absolutely and excellent bottom flatness for observation of target. This enables to obtain high-precision data for cell analysis. Also, we developed Zeon original coating (ZOC) reagent specialized for COP surface. It is suitable for various cells including neurons derived from human induced pluripotent stem cells (iPSC), primary cells, general cell lines, and so on. ZOC coated COP microplates (ZOC plates) are fully-precoated and ready-to-use. Methods We evaluated the following points regarding ZOC plates. The cells used were derived from human iPSC. [1. Storage stability] ZOC plates were stored at room temperature for a long time. After that, cardiomyocyte cells were cultured for 3 days on the plates. The cell adhesion and beat rate were evaluated. [2. Neurite extension] Dopaminergic neurons were cultured for 14 days, then the neurite extension was evaluated. For comparison, a conventional poly-D-lysine* (PDL) coating was used. [3. Lot-to-lot variation] COP microplates coated with different lots of ZOC reagents were prepared. Glutamatergic neurons were cultured for 14 days on those plates, then the neurite extension and cell morphology were evaluated. *The typical coating reagent applied for neuronal culture. Results [1.] ZOC plates stored over 12 months at room temperature showed excellent cell adhesion, and the beat rate was equivalent to prepared just before use. [2.] ZOC plates tended to extend neurites more than PDL coated plates. [3.] No variation between lots was observed on ZOC plates regarding the neurite extension and cell morphology. Conclusions We suggest applying the combination of high accuracy for cell imaging using COP microplates and high performance for cell culture using ZOC can provide high precision data at bioassay research. This would be a significant value for development of drug screening processes at pharmaceutical company.

Recent development in polymer coating to prevent corrosion in metals: A review

Corrosion in metals is a pervasive and costly issue across various industries, from infrastructure to manufacturing. Corrosion is a complex electrochemical process, and mitigating it is paramount to extend the lifespan and maintain the integrity of metal structures and components. This review study provides a thorough overview of the state-of-the-art use of polymer coatings to stop metal corrosion. It then delves into polymer coatings’ essential properties and advantages, highlighting their role in corrosion inhibition. The paper surveys recent advancements in polymer coating techniques and their compatibility with different metal substrates. The case studies and real-world applications where polymer coatings have been successfully employed to prevent corrosion in diverse settings, including marine environments, automotive components, and aerospace structures, are explored. Case studies illuminate the efficacy of these coatings, showcasing their role in safeguarding assets, reducing maintenance costs, and promoting sustainability. By analyzing these cases, the paper elucidates the practical effectiveness of polymer coatings in corrosion prevention. This review article addresses numerous ways of shielding metals from corrosion, focusing on nanomaterials, conducting polymers, nano-composites, and carbon-based materials for corrosion resistance. This literature review stands out for its thorough analysis of the most recent developments in this field and the ways in which various polymer coatings are being used to prevent corrosion.

Unique polymer‐based composite coating with high anti‐corrosion characteristics and functional fillers

AbstractThe objective of this research is to develop a composite polymer coating with increased thermal conductivity and corrosion resistance for protecting structural materials in heat exchange apparatuses. Chemically pure compounds such as graphene, boron nitride, tyrosine, sodium hydroxide, zinc pyrophosphate, ethyl acetate, and epoxy resin with the addition of secondary polypropylene were utilized as raw materials. The obtained coatings were evaluated using an emission scanning microscope equipped with an energy‐dispersive spectroscopy (EDS) detector. Electrochemical activity was measured using standard equipment within a frequency range of 0.1–0.01 Hz. Thermal conductivity and corrosion resistance were measured at 0.24 W/m K and 9.70 Ω/cm2 when using only epoxy resin with the addition of secondary polypropylene. When employing a composite consisting of epoxy resin with the addition of secondary polypropylene, boron nitride, graphene, tyrosine, and zinc pyrophosphate, the thermal conductivity and corrosion resistance values were 1.65 W/m K and 11.10 Ω/cm2, respectively. Polymer coatings containing 30% composite demonstrated the highest thermal conductivity (1.65 W/m K) and corrosion resistance (11.20 Ω/cm2). The research findings can be utilized to create polymer coatings with enhanced thermal conductivity and corrosion resistance values. This polymer coatings could serve as structural materials for heat exchange devices.Highlights Corrosion resistance increase with complexing of composite coating. Thermal conductivity increase with complexing of composite coating. Use of epoxy resin with secondary polypropylene make thermal conductivity value.

Constructing ZSM-5 loaded with 2-mercaptobenzimidazole on glass fiber for enhancing the anti-corrosion and erosion resistance properties of epoxy coating

Glass fiber reinforced polymer coatings (GFRPC) are used to protect steel structures in harsh Marine environments due to high mechanical strength and chemical stability. The composite coating not only suffers from impact damage by seawater and sediment but also experiences corrosion damage in the splash zone. However, the GF has weak interfacial adhesion with polymer resins due to the chemical inertia and smooth surface, which limits the service lifespan of GFPRC. Hence, ZSM-5 zeolites were in situ prepared on the surface of glass fibers by hydrothermal synthesis, and 2-mercaptobenzimidazole (MBI) was further adsorbed to obtain difunctional hybrid glass fibers (ZGFM) to enhance the interfacial adhesion strength of glass fiber/resin and also the erosion resistance and anti-corrosion ability of composite coatings. Compared to GF/EP, the interfacial shear strength of ZGFM/EP was increased by 104.39 %. After immersion under an alternating hydrostatic pressure of 20 MPa for 12 days, the impedance value of the ZGFM/EP composite coating remained at 6.40 × 109 Ω•cm2, demonstrating outstanding deep-sea anti-corrosion performance. Following the erosion test, the ZGFM/EP exhibited a reduction in mass loss and volume loss by 10.65 % and 12.55 %, respectively, in comparison to the pure EP coating. The excellent interfacial strength between ZGFM and EP ensured effective stress transfer, which prevented crack propagation, thus enhancing the mechanical properties and erosion resistance of the composite coating. Meanwhile, electrochemical experiment proves glass fiber with MBI loaded obviously inhibited the corrosion reaction.

Protective graphene-based coatings for Zamak: Physical and electrochemical analysis

Concerns surrounding the widespread use of hazardous materials have increased over time and have led numerous states to implement regulations aimed at preserving human and environmental health. In response, industries like metallurgy have gradually transitioned from traditional, hazardous technologies to safer alternatives, such as using polymeric coatings to protect metals from corrosion. This study focuses on evaluating the protective properties of non-functionalized graphene oxide-based coating (GC) and functionalized graphene oxide-based coating (FGC) on the zamak samples. First, the powders were analyzed from structural, morphological, and spectroscopic perspectives. The formation of amino-silica groups on the graphene oxide sheets was confirmed through SEM-EDS, XRD, and FTIR analyses, validating the success of the functionalization process. Granulometric analysis demonstrated a good dispersion of fillers in the mixtures. Cross's theoretical model was applied to the rheological experiments to find the optimum way of coating application on metallic substrates. The corrosion resistance of the coatings was evaluated using OCP, LSV, PS, EIS, and salt spray experiments. The results revealed that the functionalized graphene oxide coating provided superior corrosion protection compared to other coatings on Zamak samples. AFM topographic images, along with roughness measurements, indicated a significantly less corroded surface when using the functionalized graphene oxide coating. Additionally, Raman spectroscopy confirmed the protective effectiveness of the FGC coating against corrosion.

TCT-430 Sirolimus-Eluting Stent With Abluminal-Only Biodegradable Polymeric Coating in the Treatment of Native Coronary Artery Lesions: Results of the Prospective Multicenter Inspiron Real Life II and Latitude Trials

TCT-430 Sirolimus-Eluting Stent With Abluminal-Only Biodegradable Polymeric Coating in the Treatment of Native Coronary Artery Lesions: Results of the Prospective Multicenter Inspiron Real Life II and Latitude Trials

Realizing Ultrahigh Cycle Life Anode for Sodium-Ion Batteries through Heterostructure Design and Introducing Electro Active Polymer Coating.

Bi2S3 has attracted increasing attention in sodium-ion batteries (SIBs) for its high theoretical capacity and low discharge platform. However, the sodium storage performance of Bi2S3 is limited by poor electrical conductivity and volume expansion during cycling. Herein, we report a special polypyrrole (PPy)-coated MoS2/Bi2S3 (MBS@PPy) heterostructure composite obtained by hydrothermal reaction as an anode material for SIB. As a result, the MBS@PPy composites demonstrate exceptional electrochemical performance in SIB, exhibiting a high capacity of 361.1 mA h g-1 at 10 A g-1 and showcasing remarkable rate performance. Even under a high current density of 35 A g-1, the specific capacity remains stable at 280 mA h g-1 after 2,000 cycles. Furthermore, a successfully assembled Na3V2(PO4)3//MBS@PPy sodium-ion full cell can achieve an impressive specific capacity of approximately 400 mA h g-1 after 300 cycles at 0.5 A g-1. In MBS@PPy composites, the polypyridine coating not only improves the interfacial conductivity of nanorods but also effectively inhibits the agglomeration between nanorods due to large volume changes. The MoS2 heterostructure further inhibits the coarsening of the internal structure, improves electron transport and reaction kinetics, and increases the rate capability of the material. This work provides an effective strategy to develop energy storage materials with superior electrochemical properties.

Antibacterial cationic porous organic polymer coatings via an adsorption-contact-photodynamic inactivation strategy for treatment of drug-resistant bacteria

Although photodynamic therapy (PDT) has great potential for treating severely infected wounds, it is restricted by the short lifetime, limited diffusion distance of reactive oxygen species (ROS), and incomplete contact with bacteria. Herein, we report a novel nanosized ionic porous organic polymer (TPAPy-IPOP) based on the triphenylamine (TPA) moiety. Strong electron-deficient cationic groups were introduced into TPA to construct the donor–acceptor (D–A) system, in which the photoelectric effect of TPAPy-IPOP was greatly enhanced, and it was easily excited to produce ROS under irradiation with visible light. The introduction of cations not only facilitated bacterial adsorption by TPAPy-IPOP via electrostatic attraction, which was more conducive to killing bacteria by ROS, but also inactivated bacteria by the cations directly. The nanosized TPAPy-IPOP remained suspended in water for several months and could be sprayed onto various substrates to form a durable coating with excellent antibacterial properties. The in vivo results proved that the silk fibroin/polyvinyl alcohol non-woven fabric (SF/PVA) coated with TPAPy-IPOP could create and maintain a sterile microenvironment at a wound site. The rapid reduction in inflammation resulting from its bactericidal action accelerated the wound healing rate. Collectively, this design is expected to offer a generalizable approach for developing novel antibacterial therapeutic photosensitizers, especially for infected wound treatment.

Swelling and Degrafting of Poly(3-sulfopropyl methacrylate) Brushes.

Upon exposure to a good solvent, polymer brushes prepared via surface-initiated polymerization can undergo degrafting via cleavage of bonds that anchor the polymer tethers to the underlying substrate. As polymer brushes are often used in a solvent swollen state, this has implications for the longevity of these polymer coatings. Improving the fundamental understanding of this process is thus also of practical importance. It is believed that degrafting is the consequence of tension amplification at the bonds that anchor the polymer grafts, which is driven by swelling of the polymer brush film. Taking advantage of the sensitivity of the swelling behavior of poly(3-sulfopropyl methacrylate) (PSPMA) brushes toward changes in ionic strength, this study has investigated the degrafting behavior of these brushes in aqueous media at different LiCl and NaCl concentrations. The aim of these experiments was to investigate whether the rate constant of the degrafting process was correlated with the swelling ratio of the PSPMA brushes. The experiments show that in aqueous LiCl solutions, the initial rate constant of the degrafting process is correlated with the swelling ratio of the PSPMA brush. This observation represents a first example of the correlation between these two parameters for hydrophilic polymer brushes in aqueous media and supports the idea that degrafting is a mechanochemical process driven by a swelling-induced tension at the polymer-substrate interface.

Mechanistic elucidation of the molecular weight dependence of corrosion inhibition afforded by polyetherimide coatings

Corrosion of critical metal components exacts a heavy toll in terms of maintenance and replacement costs and damage to ecosystems upon failure. Polymeric barrier coatings protect against corrosion; however, design principles for modulating polymer structure to improve corrosion inhibition remain contested and elusive. Here, we examine molecular-weight-dependent differences in the efficacy of corrosion inhibition on aluminum substrates afforded by polyetherimide (PEI) coatings. Analyses of coated substrates evidence a clear trend denoting improved corrosion inhibition for higher weighted-average molecular weight (MW) PEI. The more rigid and entangled macromolecular network of higher-MW variants exhibit stable impedance values, |Z|0.01 Hz ca. 1010 Ω/cm2, upon extended immersion in brine media, whereas lower-MW variants are readily hydrated and disentangled resulting in a significant reduction in impedance values. Results illuminate mechanistic understanding of molecular-weight-dependence in corrosion inhibition, advance a framework for considering the dynamical evolution of secondary structure, and exemplify generalizable design principles for corrosion inhibition.

2D-nanostructures as flame retardant additives: Recent progress in hybrid polymeric coatings

The use of polymers in day-to-day life is undeniable; nevertheless, applicability of these polymers in the fire risk sector poses serious limitations as most of the polymeric materials/coatings employed are prone to fire. Hence to improve the fire retardant (FR) properties of polymers, researchers recommend the use of FR materials/additives, either physically blended or incorporated chemically via suitable modifications. However, to achieve sufficient FR property, usually higher amounts of traditional FRs are required which understandably deteriorates the mechanical and other important properties of the polymers. Moreover, use of halogenated FRs are under immense scrutiny due to the possible release of carcinogenic and organic pollutants. As a result development of halogen-free FRs is an emerging field of research. In this context, incorporation of nanostructured two-dimensional (2-D) materials to form polymer composites that can not only reinforce the mechanical, thermal and other important properties but also improve flame retardancy has opened up new prospects. The 2-D nanostructured materials, particularly, layered double hydroxide (LDH), MXenes, Graphene and its derivatives, Boron Nitride (BN) and molybdenum disulphide (MoS2) have demonstrated capabilities to enhance the FR properties as a green and environmentally benign material. Incorporation of these 2-D materials into polymers to form nanohybrids can be achieved either as conventional filler or as surface modified systems chemically bonded to the parent matrix. In the present review, the recent development strategies of surface modifications employed on 2-D nanostructured materials (LDH, MXenes, GO, BN and/or MoS2) to form polymeric nanocomposites and the FR properties achieved are discussed. The significant outcomes reported by various research groups, the key insights gained and viewpoints are deliberated. A plausible underlying mechanism for flame retardancy offered by 2-D nanostructured materials (LDH, MXenes, GO, BN and/or MoS2) based polymer nanocomposites as extended by several research groups is discussed.

Surface Damage by Physical Cleans during Semiconductors Manufacturing

This paper investigates surface damage caused by physical cleaning processes during semiconductor manufacturing. The study focuses on various materials, including FDSOI wafers and polymer films, subjected to high-velocity sprays and cryogenic cleans. Thanks to the supplier process performances and quality control, FDSOI films do not present any specific concern linked with this failure mode. This latter can be observed on whatever films exposed to aggressive physical cleans and the wafers are cleverly used as a test vehicle to evidence surface defects with a revelation method using a wet etchant. It enables the detection of nano-cracks and other damages. Same defects are observed in bulk silicon wafers, and solutions exist to avoid these damages. Different spray types are compared, highlighting the impact of droplet energy distribution on surface integrity. Additionally, a direct characterization method using polymer films is developed to assess physical cleaning damage. The findings emphasize the importance of optimizing cleaning processes to balance defect removal efficiency and surface preservation. Emerging cleaning solutions like polymer coat and peel methods are also discussed for their potential to offer high cleaning performance with minimal surface damage.

Experimental Study on Improving the Impermeability of Concrete under High-Pressure Water Environments Using a Polymer Coating

The concrete lining of high-pressure water conveyance tunnels permeates under high-pressure water. Dense and hydrophobic coating can effectively improve the impermeability of concrete. However, the coating exhibits varying impermeability in different high-pressure environments, which can even lead to coating detachment or damage. The objectives of this study are to improve the high-pressure impermeability of concrete by using a polymer coating, and to study the varying impermeability through experiments. This study applied a polymer coating called SCU-SD-SP-II (SSS) to concrete surfaces, and it formed a composite protective layer with an epoxy-modified silicone (EMS) coating. A series of high-pressure impermeability tests were conducted to study the seepage regulation of the coated concrete and the failure mechanism of the SSS coating under cracks in the concrete. The results indicate that the SSS coating has excellent impermeability. Pressurized water of 3 MPa could not permeate the SSS coating with a thickness of 0.5 mm within 24 h. Under both external and internal water pressure conditions, the SSS coatings improved concrete impermeability. Additionally, the average seepage height and relative permeability coefficient of the latter decreased by 49.6% and 71.2%, respectively, compared with the former. After concrete cracking, the SSS coating could withstand 3 MPa pressure on crack surfaces smaller than 1 mm. When the crack width was greater than 2 mm, the SSS coating deformed under 1 MPa pressure. As the pressure increased to 2 MPa or even 3 MPa, the SSS coating was punctured or torn due to stress concentration. This study provides new insights into the impermeability of concrete under high water pressure.

Investigation of tribology and life prediction of polymer coatings on 7N21 aluminum alloy under dry sliding wear

To improve the tribological properties of the 7N21 aluminum alloy under dry sliding wear conditions, three E44-PI-PAI composite coatings filled with varying contents of MoS2, h-BN and VN were designed. The mechanical and tribological performances of these coatings were evaluated using scratch experiments, nanoindentation, and sliding wear experiments. After identifying the optimal coating, the engineering constants of the coating were determined using tensile experiments. Finally, a simulation analysis of the reciprocating wear life was performed using ABAQUS and a custom-developed UMESHMOTION subroutine. The results indicate that the optimal ratio of MoS2, h-BN and VN in the designed polymer coating is 4:3:4. The coefficient of friction (CoF) and wear rate of the optimal coating are 0.189 and 0.444×10−14 m3/Nm, representing a 67 % reduction in CoF compared to the 7N21 aluminum alloy. The L2 coating demonstrates excellent compatibility, featuring a surface roughness (Ra) of 0.630 μm, a uniform thickness of 10±2 μm, an optimal bonding strength at level 0, and a nanohardness of 0.391 GPa, meeting the requirements for engine bearings. The maximum deviation between the simulated wear life prediction and experimental results is only 8.11 %.

Low-frequency EIS interpretation with the potential to predict the durability of protective coatings

Obtaining impedance response with predictive value for coating durability is central to meeting today's protective coatings end-user requirements. Here we present a novel approach to interpreting the low-frequency impedance of industrial coatings that takes into account the relevance of the coating properties that determine their barrier and adhesion durability. Modern, high adhesion, low VOC polymer coatings utilize cross-linking chemistry with polar or hydrogen bonding materials, leading to the apparent paradox that coatings exhibit corrosion creep values that are very low and inversely related to the barrier effect derived from the EIS response. In practice, once the corrosion creep rate is negligible, the ability of a coating to act as a long-term effective barrier, especially at edges and welds, becomes a major concern, and the improvement in durability relies on the improvement of the barrier. In the present study, we investigated the barrier effect of conventional partial and full offshore coating systems with epoxy and epoxy mastic layers applied without and with zinc-rich or zinc phosphate primers and polyurethane topcoats. The panels were aged for two years in an atmospheric offshore-like conditions and subsequently exhibited defects due to inadequate coating thickness, number of layers, surface preparation and inadequate application practice. EIS measurements were performed on the panels in the laboratory in dry and wet state. EIS provided a quantitative rating of the barrier effect that can serve as a basis for informed upgrading of coating solutions, application practices or workmanship quality, particularly in structures with limited access where high durability is an imperative.

Magnetic Nanoparticles with On-Site Azide and Alkyne Functionalized Polymer Coating in a Single Step through a Solvothermal Process.

Background/Objectives: Magnetic Fe3O4 nanoparticles (MNPs) are becoming more important every day. We prepared MNPs in a simple one-step reaction by following the solvothermal method, assisted by azide and alkyne functionalized polyethylene glycol (PEG400) polymers, as well as by PEG6000 and the polyol β-cyclodextrin (βCD), which played a crucial role as electrostatic stabilizers, providing polymeric/polyol coatings around the magnetic cores. Methods: The composition, morphology, and magnetic properties of the nanospheres were analyzed using Transmission Electron and Atomic Force Microscopies (TEM, AFM), Nuclear Magnetic Resonance (NMR), X-ray Diffraction Diffractometry (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), Matrix-Assisted Laser Desorption/Ionization (MALDI) and Vibrating Sample Magnetometry (VSM). Results: The obtained nanoparticles (@Fe3O4-PEGs and @Fe3O4-βCD) showed diameters between 90 and 250 nm, depending on the polymer used and the Fe3O4·6H2O precursor concentration, typically, 0.13 M at 200 °C and 24 h of reaction. MNPs exhibited superparamagnetism with high saturation mass magnetization at room temperature, reaching values of 59.9 emu/g (@Fe3O4-PEG6000), and no ferromagnetism. Likewise, they showed temperature elevation after applying an alternating magnetic field (AMF), obtaining Specific Absorption Rate (SAR) values of up to 51.87 ± 2.23 W/g for @Fe3O4-PEG6000. Additionally, the formed systems are susceptible to click chemistry, as was demonstrated in the case of the cannabidiol-propargyl derivative (CBD-Pro), which was synthesized and covalently attached to the azide functionalized surface of @Fe3O4-PEG400-N3. Prepared MNPs are highly dispersible in water, PBS, and citrate buffer, remaining in suspension for over 2 weeks, and non-toxic in the T84 human colon cancer cell line, Conclusions: indicating that they are ideal candidates for biomedical applications.

FEATURES OF WASHING WATER-SOLUBLE PHOSPHORUS-AMMONIUM SALTS OF FIREPROOF WOOD COATING

The article analyzes fire-resistant materials for wooden building structures and establishes the need to develop reliable methods of researching the process of washing out flame retardants from the surface of the building structure, which are necessary for the creation of new types of fire-resistant materials. Therefore, there is a need to determine the conditions for the formation of a barrier for leaching and to establish a mechanism for inhibiting the transfer of moisture to the material. In this regard, a mathematical model of flame retardant leaching has been developed, when a polymer shell made of organic material is used as a coating, which allows evaluating the effectiveness of the polymer shell based on the amount of flame retardant washed out. According to experimental data and theoretical dependences, the dynamics of release of flame retardants from the fire-resistant layer of the coating, which does not exceed 1.0%, is calculated, and accordingly provides fire protection of wood. The results of determining the loss of mass of the sample during exposure to water indicate an ambiguous effect of the nature of the protection on leaching. In particular, this assumes the availability of data sufficient for qualitatively carrying out the process of inhibiting moisture diffusion and identifying, on its basis, the moment in time when the decline in coating efficiency begins. Experimental studies have confirmed that a sample of fire-resistant wood after exposure to water for 30 days withstood the influence of heat flow. In particular, the loss of wood mass after temperature exposure was less than 6%, and the temperature of flue gases did not exceed 185 ºС. Thus, there are reasons to assert the possibility of targeted regulation of wood fire protection processes through the use of polymer coatings capable of forming a protective layer on the surface of the fire retardant material, which inhibits the rate of flame retardant leaching.