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The process of frictional processing of a plasma coating made of R6M5 steel on a cylindrical substrate has been developed and studied. Friction processing was carried out for 10–70 s by cyclic application of pressure of 30 MPa of two tools made of R18M5 steel on a coating rotating at a speed of 900 rpm, including additional movement of tools along the generatrix of the cylindrical substrate. With an increase in the friction treatment time, the coating surface temperature rises to 1202°C, which is sufficient for plastic deformation of the coating material. The coating microhardness after plasma spraying is 3.13 GPa; after friction treatment, it increases to 7.64 GPa. The large degree of deformation of the upper layers of coating under the action of tools determines the increase in the microhardness of the coating from the substrate to the free surface from 5.85 to 7.64 GPa. [ABSTRACT FROM AUTHOR]

Surgical site infections (SSI) are major post‐operative complications following surgery. Reducing SSI is a global urgency as they account for huge pecuniary, physiological, and emotional burdens for patients. Antibiotic resistance is the main challenge for surgeons dealing with SSIs. Aggregation‐induced emission photosensitisers (AIE PS) with their distinct optical characteristics, biocompatibility, low toxicity, and target specificity, hold the potential for the treatment of SSI. Herein, a synergetic strategy combining plasma polymerization and AIE PS is adopted to develop coatings that can eradicate SSI‐causing bacteria. These coatings can preferentially kill Gram‐negative and Gram‐positive bacteria over mammalian cells after triggered by light irradiation. The cell viability and immunostaining studies confirmed their biocompatibility on mammalian cells. The antibacterial mechanistic studies explored their ability to generate reactive oxygen species (ROS), which is crucial for overcoming antibiotic resistance. Thus, this study opens an avenue toward antibacterial coatings to decrease the prevalence of SSI. [ABSTRACT FROM AUTHOR]

In the quest to curtail the spread of healthcare-associated infections, this work showcases the fabrication of a cutting-edge antibacterial textile coating armoured with aggregation-induced emission photosensitisers (AIE PS) to prevent bacterial colonisation on textiles. The adopted methodology includes a multi-step process using plasma polymerisation and subsequent integration of AIE PS on their surface. The antibacterial effectiveness of the coating was tested against Pseudomonas aeruginosa and Staphylococcus aureus after light irradiation for 1 h. Furthermore, antibacterial mechanistic studies revealed their ability to generate reactive oxygen species that can damage bacterial cell membrane integrity. The results of this investigation can be used to develop ground-breaking explanations for infection deterrence, principally in situations where hospital fabrics play a critical part in the transmission of diseases. The antibacterial coating for textiles developed in this study holds great promise as an efficient strategy to promote public health and reduce the danger of bacterial diseases through regular contact with fabrics. [ABSTRACT FROM AUTHOR]

The paper presents results of transmission electron microscopy of the plasma coating/substrate interface. Its elemental and phase compositions and defect substructure are investigated. The high-speed steel R18-Yu coating is deposited in argon medium onto the type 30HGSA steel substrate high-tempered for several times. It is shown that both the coating and substrate are mutually alloyed. Primarily the substrate demonstrates a multi-phase, multi-element sub-nanoclystalline structure with the lamellar morphology. It is shown that multiple high-temperature tempering leads to the formation of carbide nanoparticles both in the volume and at the boundaries of the martensite lath structure. [ABSTRACT FROM AUTHOR]

Abstract Surgical site infections (SSI) are major post‐operative complications following surgery. Reducing SSI is a global urgency as they account for huge pecuniary, physiological, and emotional burdens for patients. Antibiotic resistance is the main challenge for surgeons dealing with SSIs. Aggregation‐induced emission photosensitisers (AIE PS) with their distinct optical characteristics, biocompatibility, low toxicity, and target specificity, hold the potential for the treatment of SSI. Herein, a synergetic strategy combining plasma polymerization and AIE PS is adopted to develop coatings that can eradicate SSI‐causing bacteria. These coatings can preferentially kill Gram‐negative and Gram‐positive bacteria over mammalian cells after triggered by light irradiation. The cell viability and immunostaining studies confirmed their biocompatibility on mammalian cells. The antibacterial mechanistic studies explored their ability to generate reactive oxygen species (ROS), which is crucial for overcoming antibiotic resistance. Thus, this study opens an avenue toward antibacterial coatings to decrease the prevalence of SSI.

The structure and properties of plasma coatings sprayed with a composite material based on a self-fluxing NiCrBSi alloy (PG-10N-01 alloy) modified with a composite material obtained by self-propagating high-temperature synthesis were studied. Titanium powders, carbon black, aluminum, iron oxide, PT-NA-01 thermosetting powder and PGOSA-0 refractory clay were used as the initial components of modified with a composite material. Mixing and mechanical activation of the initial powders was carried out in a BM-1 ball mill for 15 minutes at 130 rpm in a ratio of 1 to 40 of the mass of the charge to the mass of the falling bodies (steel balls with a diameter of 6 mm). Initiation of the self-propagating high-temperature synthesis was carried out using a special device by introducing a heated nichrome spiral. The process of coatings spraying was performed on the MPN-004 microplasma spraying unit at a current of 45 A, a voltage of 30 V with a distance of 100 mm on samples made of 65G steel with a thickness of 3 mm. Argon was used as a plasma-forming and shielding gas. In order to substantiate the feasibility of the self-propagating high-temperature synthesis, a part of the samples was sprayed with a self-fluxing alloy PG-10N-01 with the addition of a mechanical mixture of starting powders. It was established that as a result of plasma spraying of the PG-10N-01 alloy and the composite material of the modified with a composite material + PG-10N-01 composition, coatings with a dense and multiphase structure are formed. The microstructure of the PG-10N-01 alloy coating consists of a solid solution based on nickel (γ-Ni) with inclusions of nickel borides Ni3B and chromium carbides Cr3C2. When adding modified with a composite material in a nickel-based solid solution, in addition to the phases indicated above, borides of titanium TiB2, carbides of titanium TiC and silicon SiC were detected. Their presence leads to an increase in the microhardness of such coatings and their greater wear resistance under conditions of abrasive wear in comparison with the spraying coating of the PG-10H-01 alloy.

Cold plasma coating technology for surface functionalization of pharmaceutical powder particles is a promising approach to introduce new characteristics such as controlled release layers, improved powder flow properties, stability coatings, and binding of active components to the surface. This is typically achieved in a fluidized bed reactor, where a jet containing the chemical precursor and the plasma afterglow is introduced through a nozzle while extra fluidization gas is injected from the bottom plate. However, the process requires proper mixing of the particles and precursor inside the plasma active zone to ensure a homogeneous coating of all particles. Therefore, such coating processes are challenging to optimize, given the complex phenomena involved in fluidization, plasma species reactions, and surface reactions. In this study, we use the CFD-DEM approach as implemented in the CFDEM®coupling package to model the process. The functionalization rate is modeled as mass transfer from the surrounding gas onto the particles, using a plasma coating zone where this transfer may happen. Mass transfer is switched off outside this zone. The DEM contact parameters and drag force are calibrated to our cellulose beads model powder using experimental tests composed by the FT4 rheometer and spouting tests. We show that while the chemistry can make or break the process, the equipment design and process conditions have a non-negligible effect on the coating metrics and thus must be considered. Cases where the fluidization flow is not high enough to produce good mixing have a high coefficient of variation of the coating mass, and therefore, they must be avoided. In addition, we also proposed an extrapolation procedure to provide results at longer coating times, showing that it is possible to predict coating performance even when simulations of the process for more than a minute are not computationally efficient.

In photovoltaic (PV) modules, resistive solder bond (RSB) hotspots are the primary cause for a reduction in output power of over 25%. They may be the result of inadequate soldering between the busbars and/or between the busbars and the interconnector ribbon during the circuit assembly procedure for the PV module. This study proposes a straightforward, dependable, and rapid method for reducing RSB hotspots in PV modules using additional solder flux during the circuit soldering process. The soldering of PV modules is examined in accordance with actual conditions present in PV module manufacturers during the manufacture of circuits. Using the tab pull test and the damp heat test, respectively, the bonding strength and dependability of the soldered connectors are evaluated. Connectors soldered with flux have a void ratio of 10% that is five times lower than connectors soldered without flux. In addition, connectors with flux decrease soldering strength by a range of −1.54% to −7.69%, whereas connectors without flux decrease soldering strength by a range of −17.39% to −29.31%. During long‐term reliability evaluations on repaired 370A and 370B samples, the RSB hotspots are substantially reduced by incorporating additional flux into the circuit process. In addition, the application of additional solder at the busbar to interconnetor ribbon soldering site prevents RSB hotspots effectively. The results are anticipated to provide comprehensive and straightforward solutions for significantly reducing RSB hotspot failures in commercial PV modules. [ABSTRACT FROM AUTHOR]

In the quest to curtail the spread of healthcare-associated infections, this work showcases the fabrication of a cutting-edge antibacterial textile coating armoured with aggregation-induced emission photosensitisers (AIE PS) to prevent bacterial colonisation on textiles. The adopted methodology includes a multi-step process using plasma polymerisation and subsequent integration of AIE PS on their surface. The antibacterial effectiveness of the coating was tested against Pseudomonas aeruginosa and Staphylococcus aureus after light irradiation for 1 h. Furthermore, antibacterial mechanistic studies revealed their ability to generate reactive oxygen species that can damage bacterial cell membrane integrity. The results of this investigation can be used to develop ground-breaking explanations for infection deterrence, principally in situations where hospital fabrics play a critical part in the transmission of diseases. The antibacterial coating for textiles developed in this study holds great promise as an efficient strategy to promote public health and reduce the danger of bacterial diseases through regular contact with fabrics.

The problems associated with erosion have emerged during the transportation of oil and gas. Piping industries have tried a variety of methods to comprehend the solid particle erosion. One such method is to perform coating on the substrate for effective erosion prevention. This novel work focuses on nichrome coating on duplex stainless steel (DSS2205) by atmospheric plasma spray method (APS) and detonation gun method (DGun), to minimize the erosion behavior. The velocities (150, 175 and 200 m/s), impact angles (30°, 60°, and 90°), and discharge rates (2.5, 3.75, and 5 g/min) were varied to carry out the experiments. Further, the Taguchi method is used for enhancing the performance, process, and reducing experimental cost and time. This method can optimize process parameters by combining the analysis of variance, response surface methodology, and desirability function analysis. It is evident that the coating has a significant influence on erosion behavior. Scanning electron microscope was used to examine at the degraded regions structure. The erosion resistance of the APS and DGun coatings over the uncoated specimens was increased by 29% and 52%, respectively. DGun coated specimens with a discharge rate of 2.56 g/s, flow velocity of 186.09 m/s, and impact angle of 90° were determined to have the optimum erosion rate. The DGun coating outperformed the APS coating due to its lower porosity, higher hardness, better density, and greater micro hardness. [ABSTRACT FROM AUTHOR]

Biomass corrosion is a serious problem that affects the reliability and efficiency of biomass boilers. Ni-based coatings are a potential choice to combat biomass corrosion. In this study, the Ni-clad Al coatings were prepared by air plasma spraying, and the coatings were pre-oxidized in an air atmosphere at 700 °C for 6 h. The corrosion resistance of the as-sprayed and pre-oxidized Ni-clad Al coating exposed to KCl was studied at 600 °C for 168 h. The as-sprayed Ni-clad Al coating showed a much higher corrosion rate due to the porous nature of the coating and faster penetration of corrosion products. The pre-oxidation treatment significantly reduced the corrosion rate of the Ni-clad Al coating. The maximum weight gain of the pre-oxidized Ni-clad Al coating was reduced by 23.5% compared to the as-sprayed Ni-clad coating. After pre-oxidation, multiple NiO layers were formed, and voids were significantly reduced. The corrosion products on the surface of the coating changed from nickel-rich oxides to aluminum-rich oxides after the pre-oxidation treatment. [ABSTRACT FROM AUTHOR]

The problem of the article is designed to reveal the proposed, developed and researched new method of improving the adhesion strength of plasma wear-resistant coatings on the outer surfaces of weapons made of high-alloy, heat-resistant steels, using additional cyclic (3–4) times their heating by laser radiation to temperatures of 0.6–0.8 Tpl for a few milliseconds. The purpose of increasing the resource of use and the quality of the appearance of the weapon by applying wear-resistant coatings with increased adhesion strength to the base using plasma gas-thermal spraying followed by laser thermal cycling. Determination of the main factors and parameters of the process of laser thermocycling of plasma coatings, their interrelationships, development of an algorithm for determining the conditions of laser thermocycling, establishment of the rational range of their values by mathematical modeling and experimental research. The results of mathematical modeling of laser cyclic heating of plasma coatings of HTN of different thicknesses are presented, which allows determining the irradiation parameters that ensure their heating to temperatures at the ‘coating-substrate’ boundary ≤ 1000 °С, on the surface – to Т < Тpl, at maximum cooling rates. It has been proven that laser thermocycling provides an increase in the adhesion strength of coatings to the base from 14–18 to 90–110 MPa, a decrease in porosity from 10–12 % to 7–8 %, which is due to the redistribution of alloying components at the “coating–base” interface, with the formation of elements of the metallurgical connection, contributes to a significant increase in wear resistance and a decrease in the coefficient of friction due to the formation of secondary ultradispersed film structures. We consider laser thermocycling of plasma coatings is an effective method of improving their quality and strength of adhesion to the base. [ABSTRACT FROM AUTHOR]

For the generation of tailor-made polymer coatings on nanofibrous nonwovens plasma enhanced chemical vapor (PECVD) is a promising process, even for complex geometries. The plasma coatings can greatly improve their suitability for biomedical applications by optimising biocompatibility to the local needs, especially for cardiovascular disease treatments. Therein, wound healing and endothelialisation are important steps which are connected by a complex interaction. The monomers allylamine and hexamethyldisiloxane, as well as different process conditions were studied for the coating of nanofibrous thermoplastic silicone polycarbonate polyurethane (TSPCU) nonwovens. Aim of this study was to investigate the feasibility of plasma polymer coating under preservation of the nanofibrous morphological structure. Beside characterization of the nonwoven, biological evaluation with endothelial and fibroblast cells was performed. The prepared nonwoven samples support the feasibility of plasma coating under preservation of the nanofibrous structure. Also, different effects of the surfaces in contact with fibroblasts and endothelial cells could be observed.

Fiber-reinforced polymer composites have a dominating position place in a variety of applications due to the increased specific strength and modulus. C-FRP composite is the most appealing choice for fabricating massive structural bodies like airplanes, automobiles, blades of wind power generation, and so on. SiC-FRP is used in a range of different applications from water pipes or drains coverings to electronic enclosures. Natural fiber derived from plants is gradually replacing synthetic fiber as a reinforcement for polymer composites. One of the key issues with these components is their metallic and electrical properties. Therefore, in this study, atmospheric plasma spray is used to fabricate thick Tungsten Carbide and Chromium Carbide onto C-FRP, SiC-FRP, and natural Bamboo-FRP substrate. Coated specimens were examined for Micro-hardness and Micro-structure. Results showed that the coating has sufficient adhesion strength with drastically improved properties. [ABSTRACT FROM AUTHOR]

Tribological investigations had been carried out on the plasma coating (Al2O3+ ZrO2) below dry and moist abrasion stipulations according to ASTM G134. Commercial motor oil 20W40 was used as a lubricant. At a rotational speed of 200 rpm, all experiments were carried out with ordinary loads of 10, 15 and 20 Nm. Electron microscopy for scanning and AFM was used to study of the layer sprayed with paint. The outcomes of the SEM and AFM evaluation confirmed that abrasive wear is normally decided by abrasive wear in dry abrasive conditions. The lubrication and moisture check confirmed a major reduce in wear from 10 to 15 N below regular loading, and a corrosion fee larger than 15 N was once discovered below regular loading. No impact of lubrication on wear used to discovered at high loading. No impact of lubrication on wear used to be discovered at high loads. It was also cited that the plasma coating manner to improve wear resistance. The experimental statistics acquired in this study are tremendous engineering functions such as reducing equipment and internal combustion engines.

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To determine whether the adaption of neophytes to rigid gas permeable lenses (GPs) could be accelerated by changing their diameter or surface lubricity.Methods: This was a 2 part prospective double-masked randomised wear study. An GP lens (Roflufocon D material, 9.6 mm diameter) with and without a Hydrapeg plasma coating surface was worn by 119 neophytes (21.1 ± 3.5 years; 77% female) on separate occasions. A further 114 neophytes (average age 20.1 ± 1.0 years; 72% female) wore the uncoated lens with a 9.6 mm diameter lens in one randomly allocated eye and 10.1 mm (n = 51) or 10.6 mm (n = 63) in the other with a basecurve compensation keeping the fit equivalent. Lens fit and corneal staining was assessed after 20 min, and comfort and bulbar redness were assessed at the time of lens application and after 5, 10, 15, and 20 min. Participants also reported their ease of application and removal on a 5 point scale.Results: Plasma coated GP lenses or increasing diameter did not improve comfort (p = 0.673, p > 0.05) or bulbar redness (p = 0.805, p > 0.05) during a 20 min adaptation period in neophytes. In both cohorts, comfort improved and bulbar redness reduced with time (p < 0.001). Corneal staining, ease of insertion application and ease of removal did not differ with GP coating application or GP diameter (p > 0.05).Conclusion: Changing GP diameter or surface lubricity is not beneficial to the adaption of healthy neophytes. [ABSTRACT FROM AUTHOR]

This study aims to minimize the mechanical, chemical and thermal damages on the blades of a compressor used in aerospace engines by developing a superhydrophobic coating on the blade surface. In the absence of any information in open literature for the fabrication of such coatings, an one-step plasma spray process was implemented. For this, a well mixed powder of Ni and Ti was used as feedstock material. The superhydrophobicity characteristic of the coating was confirmed by the measurement of the contact (165°) and sliding angles (8 ± 1°) by the sessile drop technique. The adhesion test of the coating showed the high force of adhesion at the interface with a failure limit of 40.85 MPa. Furthermore, the abrasion test depicted an excellent abrasion resistance of the coating. These two investigations indicated that the coatings had a very high mechanical durability. The coatings also showed an excellent thermal stability up to 400 °C. Beyond this temperature (at 600 and 900 °C), the superhydrophobic characteristic changed for hydrophobic. The pH and corrosion tests were also performed to assess the chemical stability of coatings. They showed that the coatings retained the superhydrophobic property for pH ranging between 9.5 and 2.4. Beyond this range, at pH = 10 and pH = 2, the contact angles were 138° and 143°, respectively. In addition, the coatings exhibited a better corrosion resistance than the substrate and coatings developed by using other deposition techniques. [ABSTRACT FROM AUTHOR]

This work is a comprehensive study of the structure and properties of plasma eutectic coatings after thermal cyclization. This kind of treatment significantly increases the adhesive-cohesive strength of coatings. According to the results of the conducted research, the resistance against the operation of two-layer coatings in the whole temperature range is higher than for single-layer ones. This effect is achieved by the increase in adhesion properties, a decrease in the hardness gradient along the depth of the coating, and the increase in the coating's thermal stability due to the barrier properties of the doped boride layer. By controlling the size of the dispersed crystals of the penetration phases and at the same time the state of the metal matrix, it is possible to select the TCO modes in which the coatings receive optimal tribotechnical properties. [ABSTRACT FROM AUTHOR]

Developing novel antibacterial strategies has become an urgent requisite to overcome the increasing pervasiveness of antimicrobial-resistant bacteria and the advent of biofilms. Aggregation-induced emission-based photosensitizers (AIE PSs) are promising candidates due to their unique photodynamic and photothermal properties. Bioengineering structure-inherent AIE PSs for developing thin film coatings is still an unexplored area in the field of nanoscience. We have adopted a synergistic approach combining plasma technology and AIE PS-based photodynamic therapy to develop coatings that can eradicate bacterial infections. Here, we loaded AIE PSs within biomimetic bacterium-like particles derived from a probiotic strain, Lactobacillus fermentum . These hybrid conjugates are then immobilized on polyoxazoline-coated substrates to develop a bioinspired coating to fight against implant-associated infections. These coatings could selectively kill Gram-positive and Gram-negative bacteria, but not damage mammalian cells. The mechanistic studies revealed that the coatings can generate reactive oxygen species that can rupture the bacterial cell membranes. The mRNA gene expression of proinflammatory cytokines confirmed that they can modulate infection-related immune responses. Thus, this nature-inspired design has opened a new avenue for the fabrication of a next-generation antibacterial coating to reduce infections and associated burdens.

Purpose: To compare the effect of silica (Si)-based nano-coating deposited by reactive magnetron sputtering (RMP) with that of conventional surface conditioning using metal/zirconia primer alone or after air-particle abrasion on the adhesion of resin cements to zirconia ceramic. Materials and Methods: Two hundred forty zirconia ceramic blocks (Cercon) were sintered, finished with 1200grit SiC paper under water cooling, and cleaned ultrasonically in distilled water for 10 min. The blocks (4.5 mm x 3.5 mm x 4.5 mm) were randomly divided into 24 groups (n = 10) according to 3 testing parameters: a) resin cements (Multilink, Panavia F, RelyX U100), b) surface conditioning (no conditioning as control group; Metal/Zirconia Primer; air abrasion + Metal/Zirconia Primer; Si-based nanofilm + Monobond s); c) aging (no aging vs thermo cycling at 5°C to 55°C, 6000 cycles). The nanofilm was deposited by direct current using argon/oxygen plasma (8:1 in flux) on the zirconia surface. Resin cements were bonded to zirconia surfaces using polyethylene molds. The shear bond strength (SBS) test was performed using a universal testing machine (1 mm/min), and after debonding, the substrate and adherent surfaces were analyzed using optical and scanning electron microscopes to categorize the failure types. The data were statistically evaluated using 3-way ANOVA and Tukey's test (5%). Results: Resin cement type (p < 0.05), surface conditioning method (p < 0.05), and aging condition (p < 0.05) had a significant effect on the bond strength results. Interactions were also significant (p < 0.05). In the nonaged condition, while control groups presented the lowest results with all cements (0 to 5.2 MPa), the airabraded group in combination with RelyX U100 resulted in the highest SBS (21.8 ± 6.7 MPa). After aging, the SBS results decreased in the air-abraded groups for all cements (4.54 to 9.44 MPa) and showed no statistical significance compared to the Si-based nanocoated groups (4.24 to 6.44 MPa). After air-abrasion and primer application, only Panavia F and RelyX U100 cements showed exclusively mixed failures, but after nanofilm coating and silanization, all cements showed exclusively mixed failures with and without aging. Conclusion: Chemical adhesion of the resin cements tested to zirconia was similar after silica-based nanofilm deposition and air abrasion followed by primer application. [ABSTRACT FROM AUTHOR]

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Magnesium (Mg) alloys have unique properties. However, their applications are limited in working environments due to their poor corrosion resistance. Plasma electrolytic oxidation (PEO) is one of the most environmentally friendly and cost-effective ways that has been promoted to treat Mg alloys. In this study, we investigated the effect of electrical parameters on the microstructure, as well as the mechanical and corrosion resistance of AM60 alloy coated with PEO. The electrical parameters studied were current mode (unipolar and bipolar), frequency and duty ratio. The microstructure evolution of the coated AM60 substrates was studied using X-ray diffraction and scanning electron microscopy. Subsequently, the mechanical properties were determined using compression tests and microhardness measurements. The potentiodynamic polarization curves indicated that the PEO-coated samples experienced a significant decrease of 99.9% in the corrosion rate compared to the base metal. The electrochemical impedance spectroscopy findings showed that PEO coating increased the corrosion resistance of the AM60 magnesium alloy by 1071870% compared to the base metal. On the other hand, the PEO coated samples showed superior adhesion to the substrate. Moreover, the PEO coating led to an improvement in the hardness value by 114% compared to base metal, coupled with insignificant change in the compressive properties.

A common problem with most polymers is their crude oil-based production and hence their negative environmental impact. Therefore, changing to bio-based and biodegradable polymers like polylactide acide (PLA) as promising candidate could be a reasonable alternative. PLA is characterized by very good mechanical properties, but rather poor surface properties for functional applications. A material-friendly and frequently used technique for surface modification is the deposition of hydrogenated amorphous carbon (a-C:H) by plasma-enhanced chemical vapor deposition (PECVD) using acetylene. Here, a 50 μm thick PLA foil was coated with a-C:H layers of various thickness (50 nm up to 500 nm). Surface topography is analyzed with scanning electron microscopy (SEM), chemical composition by diffuse reflectance infrared Fourier transform (DRIFT), and wettability by contact angle. Additionally, layers were investigated by X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS) at the synchrotron facility BESSYII resulting in thickness dependent changes of the sp2-/sp3-binding ratio. As the layer thickness increases, the topography also changes, showing internal stress-induced cord buckling and delamination phenomena for the carbon layers. Present results provide an improved understanding for the coating of the organic biopolymer PLA with the predominantly inorganic a-C:H via in situ growth. Unlabelled Image • Plasma generated, thickness dependent a-C:H coatings on biopolymer PLA • Layer failures (cord buckling, delamination) occurred with increasing deposits. • sp3/sp2 content and chemical environment revealed thickness depended layer failures. • sp3 binding dominance shifts to sp2 with increasing thickness and causes failures. • Stable a-C:H layers resp. thicknesses on PLA were found in both regimes. [ABSTRACT FROM AUTHOR]

Abstract Hard coatings are usually applied to improve high speed steel (HSS) tools performance. However, to achieve this aim, a good adhesion between coating film and substrate is necessary. The coating failure, associated to the lack of adhesion to the substrate, can lead to tool premature wear, reducing its efficiency. The surface modification can improve the coating film adhesion levels by modifying substrates surface roughness, and then, ensuring better anchorage of the deposited layer. In this research two techniques of superficial modification, planar sputtering and chemical polishing, were compared. The sputtering uses plasma application, where cations formed in the reactor collide with samples surface, removing material from it. For chemical polishing, it was used acid and alkaline solutions. After surface treatments, all roughness levels were measured using a roughness tester. The Cathodic Cage Plasma Nitriding (CCPN) technique was used to deposit a TiN film on tools surface. Then, X-ray diffraction, Vickers microhardness and SEM tests were carried out to verify the presence of deposited film, as well as its thickness and mechanical properties, and then, machining tests with SAE 1045 steel where performed, applying the coated tools. Optical microscopy was carried out to track average flank wear up to 0.3 mm, characterizing the end of tool life. It can be observed that all the coated tools obtained an increase in its life, registering the variances according to the different roughness profiles. The best results were verified for chemical polishing with acid solution treatment condition, as it allowed longer machining time with less flank wear. Highlights • Surface texturization increased film adhesion on TiN coated HSS tools • All coated tools presented an increment in its tool life. • Amount of analysis to validate the search [ABSTRACT FROM AUTHOR]

Abstract Silver nanoparticles (NPs) are known to provide antimicrobial properties for surfaces. However, there are environmental concerns due to reports of toxicity after exposure to the environment during or after end-use. Immobilizing silver NPs to the surface of substrates could ensure that particles are readily available for antibacterial activity with limited environmental exposure. A plasma coating on top of silver NPs could improve the adhesion of NPs to a substrate, but it could also impede the release of silver NPs completely. Furthermore, silver has been shown to require direct contact to demonstrate antibacterial activity. This study demonstrates immobilization of silver NPs with plasma coating onto a surface while maintaining its antibacterial properties. Silver NPs are simultaneously synthesized and deposited onto a surface with liquid flame spray aerosol technique followed by hexamethyldisiloxane plasma coating to immobilize the NPs. Atomic force microscope scratch testing is used to demonstrate improved nanoparticle adhesion. Antibacterial activity against gram-negative Escherichia coli is maintained even for plasma coating thicknesses of 195 nm. NP adhesion to the surface is significantly improved. Gram-positive Staphylococcus aureus was found be resistant to all the plasma-coated samples. The results show promise of using plasma coating technology for limiting NP exposure to environment. Highlights • Roll-to-roll synthesis of silver nanoparticles using Liquid flame spray • Plasma coating for improved nanoparticle adhesion to substrate • Antibacterial properties of silver nanoparticles across plasma layer • Limited environmental exposure of silver nanoparticle [ABSTRACT FROM AUTHOR]

The oxidation behaviors of γ-TiAl and Mo-Si-Ti coating at 750 °C were investigated through controlling oxidation duration. Growth of Al 2 O 3 and TiO 2 divided the oxidation process of substrate into four stages with increasing duration. (i) Al 2 O 3 oxide film caused low initial oxidation weight gain. (ii) TiO 2 rod-like oxide particles destroyed the oxide film, causing increase of oxidation weight gain. (iii) Plate-like oxide particles caused by preferred orientation growth of Al 2 O 3 , hindered the rapid increase of oxidation weight gain. (ⅳ) Growth of TiO 2 rod-like oxide particles and flaking of oxide film led to rapid increase of oxidation weight gain. Mo-Si-Ti coating mainly composed of (Ti, Mo) 5 Si 3 showed a gradient structure. A diffusion layer allowed the coating to show a compositional gradient. Grain size gradually decreased from substrate to coating, with equiaxed grains near substrate and columnar grains near coating surface. Columnar grains accelerated initial oxidation as well as the production and volatilization of MoO 3 , causing holes in TiO 2 /SiO 2 oxide film and higher initial oxidation weight gain than substrate. As the duration increased, oxide film became dense and fine grains and gradient structure prevented its flaking, accompanied by low oxidation weight gain. Mo-Si-Ti coating could enhance the oxidation resistance of substrate effectively. • Isothermal oxidation behaviors of γ-TiAl and Mo-Si-Ti coating at 750 °C are studied through controlling oxidation duration. • Growth of Al 2 O 3 and TiO 2 divides the oxidation process of γ-TiAl into four stages. • The Mo-Si-Ti coating with small grain size exhibits a gradient structure. • The fine grain and gradient structure prevent the flaking of oxide film and coating, ensuring high oxidation resistance. [ABSTRACT FROM AUTHOR]

The paper presents results of research for influence of plasma jet parameters (current, spraying distance, plasmasupporting nitrogen gas consumption), fractional composition of an initial powder and cooling degree by compressed air on characteristics of anti-meteorite coatings, subsequent processing modes by pulsed plasma. Properties of the obtained coatings and results of ballistic tests have been given in the paper. The proposed methodology has been based on complex metallographic, X-ray diffraction and electron microscopic investigations of anti-meteorite aluminum oxide coating. Optimization of air plasma spraying parameters for NiAl and Al2O3 materials has been carried out in the paper. The spraying parameters optimization has been executed on the basis of obtaining maximum materials utilization factor. Surface treatment of model screen elements with a double-layer composite coating (adhesive metal NiAl layer and hard ceramic oxide Al2O3 layer) has been fulfilled while using compression plasma stream. Nitrogen has been used as working gas. Composite hard ceramic oxide Al2O3 coating is represented by porous structure consisting of 10–15 µm-size fused Al2O3 particles. Metallic inclusions formed due to erosion of plasmatron electrodes have been observed in the space between the particles. Surface of bilayer composite coatings has been processed by a compression plasma stream and due to nonsteady processes of melting and recrystallization high strength polycrystalline layer has been formed on their surface. In this context, those areas of the polycrystalline layer which had metal inclusions have appeared to be painted in various colors depending on chemical composition of the inclusions.

Corrosion is the deterioration of materials by chemical interaction with their environment. In the oil and gas industry, corrosion of the pipelines and other equipment is one of the leading causes of failure and the corrosion-related costs are very high. Hence, corrosion protection is an essential requirement. In this study, the objective is to analysis of the corrosion protection behavior of spray Alumina-Titania (Al 2 O 3 -TiO 2 ) oxide ceramic coating on carbon steel pipes C45 using two different thermal spray coatings processes. These two different thermal spraying coating, High velocity oxy-fuel (HVOF) and plasma thermal spraying techniques can be used instead of extensive treatment by expensive chemical formation of coatings on pipelines and equipment to improve or restore a component's surface properties or dimensions and to protect them from corrosion. Molten or semi-molten ceramic composite powders are sprayed on the surface in order to produce a dense coating layer. FESEM of coated samples showed that a high temperature of plasma coating method end in melting the ceramic powders and creation of completely melted regions on the coated samples’ surface compared to HVOF coating techniques. Corrosion testing of coated samples in seawater (3.5% NaCl) was conducted within 30 days. Electrochemical impedance spectroscopy (EIS) as well as potentiodynamic polarization outcomes represented that the corrosion resistivity of plasma coating technique for this type of ceramic composite is better than HVOF coating technique. However, both types of coating techniques are protecting the substrate against seawater. [ABSTRACT FROM AUTHOR]

The running-in behavior and the associated transient friction characteristics of a piston ring with different surface treatments are experimentally evaluated using a custom-made engine testing apparatus. Results are reported for a series of running-in and steady-state experiments on piston rings with different combinations of coated and textured surfaces. Comparisons are provided between five different types of piston rings: (1) with no textures; (2) with textures only; (3) with coating only; (4) first textured and then coated; and (5) first coated and then textured. A combination of the texturing and coating showed 12.5% improvement in the frictional behavior and up to 50% improvement in break-in time compared to cases when only one surface treatment was applied. [ABSTRACT FROM AUTHOR]

Nowadays, silver (Ag) coatings find widespread use in medical textiles, e.g. wound bandages, mainly due to their antibacterial properties related to the Ag ion release in aqueous media. Moreover, Ag-coated fibers offer excellent electrical properties, allowing their use for sensing applications such as electrocardiography (ECG) belts. Due to the potential cytotoxicity of Ag, electrically conductive coating systems need to be developed with reduced and time-controlled Ag release. In this study, pure silver was continuously deposited onto a polyester (PET) fiber to optimize electrical conductivity for ECG application. The pure silver coated fibers, however, showed the typical initial burst release of Ag ions when immersed in an aqueous environment locally yielding cytotoxic conditions, i.e. high Ag ion concentrations. While the ion release can be favourable for antibacterial properties, it needs to be limited for medical devices. A diffusion barrier is thus required, while maintaining the electrical conductivity. Thus, different plasma polymer top coatings were applied onto the Ag-coated fibers using a continuous deposition process. The functional plasma polymerized films (a-C:H and a-C:H:O) were compared with an ultrathin titanium oxide layer (as recently investigated) regarding electrical properties and silver release. Ag release measurements demonstrated that an efficient control over the release properties (initial burst and long-term release) was achieved depending on the hydrophobicity and thickness of the plasma polymer films. [ABSTRACT FROM AUTHOR]

The purpose of the presented paper is to optimize technological parameters of hardening high-energy processing used for sprayed coatings made of materials based on oxide ceramics with inclusions of solid lubricant. The paper presents results of the investigations on influence of power density and total number of laser irradiation impulses in a spot treatment on thickness of treated coating layers made of materials based on oxide ceramics. The considered wear-resistant coatings require increased cohesive and adhesive strength. Therefore, the total number of impulses should ensure melting and sealing of the coatings along the whole thickness that will fully contribute to obtain hardened nano-crystalline and amorphous structures.The work is based on complex metallography, X-ray diffraction and electron-microscopic investigations on modified structural elements of composite coatings being treated with highly concentrated energy sources. The following main processes of hardened plasma coating formations have been revealed in the paper: com paction of sprayed materials due to thermal and shock-wave impacts of laser irradiation impulses. In this case material porosity is decreasing, cohesive and adhesive strength of coatings is increasing, grain structure is crushed, amorphous and nano-crystalline phases of higher strength are formed all these facts are evidenced by an increase in average micro-hardness of deposited compositions. Duration of thermal laser irradiation impulse impact on the material is sufficient to activate chemical processes in the boundaries of main phases of the composite coating. This leads to formation of finely dispersed (including nanoparticle size) compounds that strengthen boundaries of the main phases and the coating as a whole. This is confirmed by the results of an X-ray diffraction analysis.

Aircraft structures are redesigned by fibre-reinforced composites mainly due to their high specific stiffness and strength. However, while using the semi-conducting composites in an aircraft it may be failed due to lightning strike damage. The existing protection techniques will increase the weight and hence negatively impacts the fuel efficiency. This paper addresses an overview of the lightning damages that occur due to the usage of composites and existing protection techniques. The Plasma coating of copper and titanium nitride on the epoxy laminate was carried out to increase the electrical conductivity on polymeric composite coatings. The surface conductance of the coated and uncoated laminate was analytically determined. And the lightning strike test was experimentally carried out and finally the tensile strength of damaged and undamaged laminates were measured. Due to the titanium nitride coating, electrical conductance of epoxy laminates was increased. Further, it was observed that the weight can be reduced up to 85% with less damage on exposure to high current and temperature when compared to the uncoated laminate. [ABSTRACT FROM AUTHOR]

These ways оf improving the quality of such coatings by melting coating and thin surface layer or base their repeated cyclic heating continuous laser radiation in the range of temperatures (T (As1) PL). In the first case the bonding strength of coating base reaches 400 - 430MPa, the second - in 4-5 times increases to 90-120MPa, while the original-15-20MPa. Laser thermal cycling are high performance, does not require the subsequent machining. [ABSTRACT FROM AUTHOR]

Introduction: Mesh-related complications especially after vaginal implantation have raised awareness lately because of severe adverse reactions and legal aspects. About 20% of patients suffer from complications after mesh insertion in the anterior vaginal wall. Autologous plasma coating of meshes prior to implantation has shown potential to improve the biocompatibility of meshes in vivo and in vitro. This innovative approach has been developed according to the IDEAL recommendations for surgical innovations. The method has still to be assessed at stage 3 accordingly.Methods: A protocol is developed for a prospective single-blinded randomized controlled phase II trial for biocompatibility optimization of anterior vaginal meshes for prolapse repair by autologous plasma coating versus non-coated meshes.Results: The protocol aims at fulfilling the requirements for stage 3 (assessment) according to IDEAL. Eligible for inclusion are women with primary cystocele, requiring a surgical procedure, suitable for randomization, and willing to be randomized. Participants will be followed up by postal questionnaires (6 months post surgery and 12 months post randomization) and will also be reviewed in clinic 12 and 24 months post surgery. Primary endpoint is the assessment of mesh-related complications following the Clavien-Dindo classifications. QoL, sexual function assessment, efficacy, and validation of an already developed long-term register are considered secondary endpoints. To afford a calculated 10% reduction of postoperative complications through plasma-coated meshes vs. non-coated meshes at 1-year follow-up, a total 214 women in each arm will be necessary to achieve 80% power at a significance level of 5%.Conclusion: The protocol for this randomized clinical trial represents the conditions to assess the surgical innovation of plasma coating of meshes in order to improve the meshes' biocompatibility at stage 3 according to the IDEAL recommendations. [ABSTRACT FROM AUTHOR]