Film Coatings Research Articles

Дослідження оптичних та електрофізичних властивостей покриттів Mn4Si7 різної товщини

Studies of Mn4Si7 coatings of different thicknesses have shown that magnetron deposition practically does not change the composition of the coating in comparison with the composition of the target. The technology and basic modes of creating the necessary targets for a magnetron sputtering device are presented. Targets were created by adding silicon and manganese powders in the required amount and heating them under vacuum conditions at high temperature and pressure. Thin silicide films (coatings) of different thicknesses were formed on the surface of silicon dioxide from the produced targets using the method of magnetron sputtering. Studies of the transmission, absorption, and reflection coefficients of coatings in the visible region of the spectrum have shown that for the Mn4Si7 coating, the reflection coefficient is practically the same at all wavelengths. It was found that the Seebeck coefficient varies from 16 µV/K to 22 µV/K, and the resistance decreases from 77 Ω to 20 Ω with increasing thickness of the thin Mn4Si7 coating.

INVESTIGATION OF VARIATION OF SPRAYING CONDITIONS ON VARIATION OF STRENGTH CHARACTERISTICS OF MoCrN COATINGS

Interest in thin-film protective coatings based on nitride compounds of molybdenum and chromium is due to the great prospects for their use as wear-resistant anti-corrosion coatings with high resistance to both external effects in the form of mechanical friction, pressure, and corrosion processes, when exposed to aggressive media, hydrogenation or high temperatures. However, the stability of nitride coatings are primarily determined by the conditions of their obtaining, which not least depend on the power of magnetron sputtering, the variation of which allows you to change the ratio of elements in the composition of coatings. The key objective of this research is to measure the strength characteristics measured by indentation method depending on the conditions of obtaining coatings under variation of sputtering power, as well as to establish the influence of variation of conditions of obtaining thin film coatings on the change of hardness and hardening factors. According to the presented data, changing the conditions of magnetron sputtering by varying the power leads to the formation of stronger stable coatings with high resistance to cracking under changing external load. In the course of research it was determined that changing the conditions of magnetron sputtering coatings, leading to an increase in the concentration of molybdenum in the composition of coatings leads to more than 60–80% hardening, as well as an increase in resistance to cracking under external influences.

Improved mechanical and fire-retardant properties of fiber-reinforced composites manufactured via modified resins and metallic thin films

Fiber-reinforced polymeric composites have been extensively used in different industrial applications because of their excellent mechanical and other properties but have lower tolerance levels for fire and lightning damage. The thermal, mechanical, and electrical conductivity of these composites can be substantially increased using some thin metallic films for higher fire resistance. The objective of this study was to develop fire-retardant fiber-reinforced composites using modified resins and metallic copper (Cu) thin films and test and characterize the mechanical and thermal properties of these prepared composites. Standard hand wet layup process was used to manufacture composite panels, and then the flame retardant and other physical and chemical properties were determined before and after resin modification and surface metal film coatings. These modified resins and the conductive metallic films of the composite provided superior flame retardancy and higher mechanical strength. The prepared composite panels made from modified epoxy via 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO) inclusion and with metallic surface coatings passed the UL-94 vertical flame testing with a V-0 rating. This composite achieved an average flexural strength of 344.2 MPa, a mean tensile strength of 400.82 MPa, and a shear strength of 6.54 MPa for single lap shear joint studies. Fractography results also show better bonding of the matrix and fiber with no significant damage. This study may open new opportunities in various composite industries.

High‐Detectivity UV–Visible–NIR Broadband Polymer Photodetector with Polymer Charge Blocking Layer Cross‐Linked by Organic Photocrosslinker

AbstractUltraviolet (UV), visible, and near‐infrared (NIR) broadband organic photodetectors are fabricated by sequential solution‐based thin film coatings of a polymer electron blocking layer (EBL) and a polymer photoactive layer. To avoid damage to a preceding polymer EBL during a subsequent solution‐based film coating of a polymer photoactive layer due to lack of solvent orthogonality, 2‐(((4‐azido‐2,3,5,6‐tetrafluorobenzoyl)oxy)methyl)−2‐ethylpropane‐1,3‐diyl bis(4‐azido‐2,3,5,6‐tetrafluorobenzoate) (FPA‐3F) is used as a novel organic cross‐linking agent activated by UV irradiation with a wavelength of 254 nm. Solution‐processed poly[N,N′‐bis(4‐butylphenyl)‐N,N′‐bis(phenyl)‐benzidine] (poly‐TPD) films, which are cross‐linked with a FPA‐3F photocrosslinker, are used for a preceding polymer EBL. A ternary blend film composed of PTB7‐Th, COi8DFIC, and PC71BM is used as a NIR‐sensitive organic photoactive layer with strong photosensitivity in multispectral (UV–visible–NIR) wavelengths of 300–1,050 nm. Poly‐TPD films are successfully cross‐linked even with a very small amount of 1 wt% FPA‐3F. Small amounts of FPA‐3F have little detrimental effect on the electrical and optoelectronic properties of the cross‐linked poly‐TPD EBL. Finally, organic NIR photodetectors with a poly‐TPD EBL cross‐linked by the small addition of FPA‐3F (1 wt%) show the detectivity values higher than 1 × 1012 Jones for the entire UV–visible–NIR wavelengths from 300 nm to 1050 nm, and the maximum detectivity values of 1.41 × 1013 Jones and 8.90 × 1012 Jones at the NIR wavelengths of 900 and 1000 nm, respectively.

Application of Spray Coating in the Fabrication of Free Standing Nanocellulose Films and Barrier Coating on the Paper Substrates

Spray coating is a novel concept for fabricating free-standing film and producing barrier coating on paper substrates. The spraying gives comparable efficacy with vacuum filtration in terms of operation time, film quality, and process intensification approach. The smooth films created by spraying nanocellulose onto the polished impermeable surface could serve as a platform for a variety of sustainable functional devices. Finally, the application of spray-coating barriers and nanocellulose films on paper substrates is the focus of the spray-coating concept designed to create smooth nanocellulose films. One of the most important factors that affect the performance of different cellulose-based functional materials is the smoothness of nanocellulose film coated with sprays in the production of flexible and printed electronics. The uses of nanocellulose film as a high-performance barrier material and the possible replacement of synthetic plastic packaging are expanded by spray coatings. The process of creating a nanocellulose film using spray coating takes less than a minute. Compared to vacuum filtering, this method offers excellent speed potential for nanocellulose films. The wet layer of spray coating takes more than 24 hours to dry in a controlled laboratory environment, using air drying. Future research projects will improve the drying process of wet films. The film spray process serves as a proof of concept, and the quality of the film produced by this method contrasts with vacuum filtration. Studying spray coating wet film drying outside the scope of this research is not part of the scope of this study, and additional research is needed in this area. The shiny film that is created by spraying nanocellulose on the impermeable polished surface can serve as a platform for various sustainable functional devices.

Modeling Analysis of Complex Deformation of Woven Coating Film during the Cyclic Tensile Process.

It is difficult for the existing Burgers model to accurately depict the off-axis cyclic drawing process of woven coatings. In this paper, the mechanical deformation of woven PVC (polyvinyl chloride)-coated film at different temperatures is investigated. One-dimensional (1D) and two-dimensional (2D) constitutive models were established to characterize cyclic deformation processes. The 1D model is an improved Burgers model. The effects of the time dependence of the viscosity coefficient and the ratio of elastic to viscous deformation are considered simultaneously. The accuracy of the 1D model for predicting the cyclic nonlinear deformation at different temperatures and loading rates is improved. The 2D model is a nonlinear orthotropic model using polynomials. On the basis of the single-objective genetic algorithm, the inverse algorithm is used to obtain the shear polynomial coefficients in the tension phase and the shear modulus in the unloading phase, which circumvents performing the difficult shear test. UMAT subroutines of off-axis stretching and off-axis cyclic stretching are written separately. The intelligent inverse algorithm program consists of a single-objective genetic algorithm program, a finite element parametric modelling program, and a UMAT subroutine. The simulation results are compared with the off-axis cyclic tensile test data to validate the effectiveness and accuracy of the proposed 2D model for the analysis of the woven PVC-coated films in the tension-shear coupling state.

졸-젤 공정에 의해 제조된 가시광선 반응형 Cr/WO₃ 도핑 이산화티타늄 광촉매 투명 코팅막

졸-젤 공정에 의해 제조된 가시광선 반응형 Cr/WO₃ 도핑 이산화티타늄 광촉매 투명 코팅막

Effect of Ag content on the friction and wear properties of electrodeposited self-lubricating Ni–Ag coating

Thin film coatings are required to improve the performance of components to resist harsh environments as the modern industry grows. In this study, Ni–Ag coatings with various Ag content were deposited on the Cu surface using an electrodeposition technique. The Ni–Ag coatings were deposited to enhance the tribological properties of the coatings and increase the service life of the friction-sliding components. Ni–6wt%Ag, Ni–8wt%Ag, and Ni–10wt%Ag coatings were deposited. A solid solution of Ni–Ag was formed in the coatings. As the concentration of NiSO4 decreased in the electrolyte, the content of Ag in the coatings increased with the granular morphological characteristics. The increase in Ag content reduces the coefficient of friction (CoF) on comparing the initial running-in period and is stable after some time. The initial decrease was due to the surface roughness. The CoF and wear rate were low for all Ag contents compared to the copper substrate due to the effect of Ag solid lubricant material in prepared coatings.

Исследование структуры и свойств пищевых биоактивных пленок на основе пектина

The purpose of the study is to establish the structure and properties of bioactive films based on pectin. The objects of study are films obtained on the basis of the structure-forming agent pectin with the addition of protein hydrolyzate as an active component. The microstructure of the produced films was determined using scanning electron microscopy; physicochemical properties (biodegradability, solubility, thickness, moisture content); bioactive properties (antioxidant capacity, ability to absorb DPPH radicals, content of polyphenols and flavonoids) spectrophotometrically. The addition of protein hydrolyzate to the composition of the pectin film changed its structural properties: a dense cellular network was formed, due to which the film became less susceptible to water and took longer to biodegrade in compost, and its thickness became smaller compared to the control. Moreover, both film samples completely turned into vermicompost after 2 weeks, which shows the high biodegradability of pectin films. The antioxidant properties of the films also improved: antiradical activity increased by 11 %, and antioxidant capacity by 49 % compared to the control sample. The introduction of protein hydrolyzate into the composition of a pectin film can solve a number of problems in the monocomponent composition of a pectin-based film, improve the structural characteristics and moisture resistance. The peptides included in the hydrolyzate, forming stable chemical bonds with pectin molecules, not only have a positive effect on the structure, but also increase antioxidant properties, which is promising for the production of bioactive food film coatings that can increase the shelf life of food products.

Insights into the Physical Characteristics of Spin Coating Films of Organometallic Materials Based on Phthalocyanine with Nickel, Copper, Manganese and Silicon

Insights into the Physical Characteristics of Spin Coating Films of Organometallic Materials Based on Phthalocyanine with Nickel, Copper, Manganese and Silicon

High voltage electrostatic field and composite coating impact on the quality of Sichuan pepper

The effects of coated film (CF), high voltage electrostatic field (HVEF), and high voltage electrostatic field combined with coated film (HVEFCF) treatment on the quality of Sichuan pepper during storage at room temperature (temperature: 25 ± 2 °C, humidity: 20 ± 2%) were investigated. The pectin (1%), sodium carboxymethyl cellulose (0.5%), and ascorbic acid (0.04%) were used to prepare the CF solution. The influence of different treatments on the colour, antioxidant activity, flavor components, OH-α-sanshool content, total phenolic content (TPC), and total flavonoid content (TFC) of Sichuan pepper during storage was evaluated. The results showed that HVEFCF treatment significantly reduced the colour change and loss of antioxidant activity of Sichuan pepper during storage. Meanwhile, HVEFCF-treated Sichuan pepper reduced the loss of flavor compounds during storage. Moreover, HVEF-treated Sichuan pepper reduced the loss of TPC and TFC by 106.16% and 44.02%, respectively, after 60 days of storage compared with the control check (CK) group. Furthermore, after 60 days of storage, the amount of OH-α-sanshool in the Sichuan pepper treated with HVEFCF was 9.72 mg/g, significantly preserving the loss of numbing compounds as compared to the CK group. To summarise, HVEFCF is a simple, cheap and efficient way to reduce the quality loss of Sichuan pepper during storage, which has a wide range of application scope in the future.

Natural weathering effects on the surface morphological and physicochemical properties of radiation curable coatings in tropical climate

The purpose of this research is to discover the effects of natural weathering on palm oil-based and petrochemical-based film coatings. The film coatings were prepared using the radiation curing approach via cross-linking. Three palm oil-based resins with TiO2 nanoparticle loading were developed: EPOLA, EPOLA-OPV, and POBUA. The petrochemical-based coatings were also developed to compare the performance of natural and synthetic coatings. The coatings were exposed to natural weathering for up to 60 days at varied angles of 0°, 45°, and 90°. The effect of natural weathering conditions on the surface morphological, physiochemical, and also flexural characteristics of coatings, as well as the discoloration visual inspection and the growth of mould or fungus on the tested specimen, was studied. The results showed that natural weathering exposure induced severe discoloration and deterioration of the polymer network structure of the coatings due to photo-oxidation reaction and the presence of fungi. Overall, palm oil-based coatings deteriorate slower than petroleum-based coatings, especially at a 90° angle. This study indicated that bioresources-based palm oil has a significant potential for interior wood varnish applications due to its superior qualities over synthetic-based coatings.

Impacts of Catalyst Ink Composition and Wet Film Thickness on Fuel Cell Catalyst Layers Fabricated by Direct Film Coating Method

Utilizing a direct film coating method (DFCM), such as doctor blade coating, offers a promising approach for efficient and scalable catalyst layer (CL) production for fuel cells. To further widen the understanding of lab-scale DFCM, the present research investigates how different Pt-based catalyst ink formulations coated via doctor blade coating with varying blade gap thickness (BGT) affect the CL quality and catalyst loading. In total, 120 CL samples were prepared by coating 20 different catalyst ink formulations with varying solids content, ionomer-to-carbon (I/C) ratio, and water-to-isopropanol solvent ratio with BGTs of 75, 125, and 200 μm. Inspection of these samples showed that the solvent ratio affects the coating uniformity, with the most uniform films achieved with a ratio of 1.67 or greater. Furthermore, increasing the I/C ratio for a given solids content ink formulation decreases the Pt loading, whereas an I/C ratio above or below 1.0 reduces cell performance due to mass transport or proton conductivity impacts, respectively. In addition, a relationship factor and equations are presented to estimate the solid weight and catalyst loading of the fabricated CL based on the ink formulation and BGT. Overall, this work provides important guidance for lab-scale DFCM fabrication of industrially relevant CLs.

Metal oxide-dispersed PDMS nanocomposite films with enhanced heat-shielding ability and optical transparency

Coatings that transmit visible light and shield near-infrared (NIR) rays of sunlight have potential applications in smart windows, thermal camouflage, and heat shielding encapsulations. Here, we report metal oxide-dispersed polymer nanocomposites as potential coating materials that possess a combination of NIR reflection and visible light transmission. Film coatings (∼600 μm) comprising nanocrystalline zinc oxide (ZnO), titanium dioxide (TiO2), and cupric oxide (CuO) in the range of 0–2 wt% in polydimethylsiloxane (PDMS) matrix are fabricated. At optimal compositions, these coatings provided up to 52 % reduction in the interior air temperature, measured at distances ∼3 cm beneath the surface, while, at the same time, retaining up to 70 % of visible light transparency. The NIR reflection may be attributed to a combination of the band gap of the pigment material and the difference between the refractive indices of the pigments and the polymer matrix. We present a design map that highlights different regimes of heat-shielding and light transmission space for PDMS nanocomposite films. The performance, when compared with existing reports, suggests that films fabricated in this work outperform previously reported polymeric coatings in providing a combination of heat shielding and optical transparency.

Enhancing wear and corrosion resistance of TiO2–Al2O3 hybrid coatings by the development of TiO2–Al2O3 bilayer film coatings

Sol-gel fabricated TiO2–Al2O3 bilayer coatings were deposited on 316L surfaces with several combinations of layers. Microstructural, corrosion, and wear features of the fabricated film coatings were examined compared to the TiO2–Al2O3 hybrid coating containing 65 % TiO2, which achieved the highest protection against corrosion and wear in the previous study. The electrochemical properties were determined through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests, whereas dry sliding tests were performed using an Al2O3 ball under 1 N. Regardless of the production parameters, rutile and α-Al2O3 phases were produced in all manufactured coatings with similar thicknesses. The coatings consisting of TiO2 at the top layers showed better anti-corrosive performance due to a dense, low-porosity, and continuous morphology of TiO2 nanoparticles, while the coatings containing Al2O3 at their top layers were determined to exhibit higher wear resistance. All bilayer film coatings increased the anti-corrosion and anti-wear performance of the hybrid coating.

Poly(β-aminoester) Physicochemical Properties Govern the Delivery of siRNA from Electrostatically Assembled Coatings.

Localized short interfering RNA (siRNA) therapy has the potential to drive high-specificity molecular-level treatment of a variety of disease states. Unfortunately, effective siRNA therapy suffers from several barriers to its intracellular delivery. Thus, drug delivery systems that package and control the release of therapeutic siRNAs are necessary to overcome these obstacles to clinical translation. Layer-by-layer (LbL) electrostatic assembly of thin film coatings containing siRNA and protonatable, hydrolyzable poly(β-aminoester) (PBAE) polymers is one such drug delivery strategy. However, the impact of PBAE physicochemical properties on the transfection efficacy of siRNA released from LbL thin film coatings has not been systematically characterized. In this study, we investigate the siRNA transfection efficacy of four structurally similar PBAEs in vitro. We demonstrate that small changes in structure yield large changes in physicochemical properties, such as hydrophobicity, pKa, and amine chemical structure, driving differences in the interactions between PBAEs and siRNA in polyplexes and in LbL thin film coatings for wound dressings. In our polymer set, Poly3 forms the most stable interactions with siRNA (Keff,w/w = 0.298) to slow release kinetics and enhance transfection of reporter cells in both colloidal and thin film coating approaches. This is due to its unique physiochemical properties: high hydrophobicity (clog P = 7.86), effective pKa closest to endosomal pH (pKa = 6.21), and high cooperativity in buffering (nhill = 7.2). These properties bestow Poly3 with enhanced endosomal buffering and escape properties. Taken together, this work elucidates the connections between small changes in polymer structure, emergent properties, and polyelectrolyte theory to better understand PBAE transfection efficacy.

Investigation of Residual Stress Behavior of TiN Coating Film on Automotive Spring Steel using Multi-arc PVD Method

Investigation of Residual Stress Behavior of TiN Coating Film on Automotive Spring Steel using Multi-arc PVD Method

Microbiological and Physicochemical Evaluation of Hydroxypropyl Methylcellulose (HPMC) and Propolis Film Coatings for Cheese Preservation.

Dairy products are highly susceptible to contamination from microorganisms. This study aimed to evaluate the efficacy of hydroxypropyl methylcellulose (HPMC) and propolis film as protective coatings for cheese. For this, microbiological analyses were carried out over the cheese' ripening period, focusing on total mesophilic bacteria, yeasts and moulds, lactic acid bacteria, total coliforms, Escherichia coli, and Enterobacteriaceae. Physicochemical parameters (pH, water activity, colour, phenolic compounds content) were also evaluated. The statistical analysis (conducted using ANOVA and PERMANOVA) showed a significant interaction term between the HPMC film and propolis (factor 1) and storage days (factor 2) with regard to the dependent variables: microbiological and physicochemical parameters. A high level of microbial contamination was identified at the baseline. However, the propolis films were able to reduce the microbial count. Physicochemical parameters also varied with storage time, with no significant differences found for propolis-containing films. Overall, the addition of propolis to the film influenced the cheeses' colour and the quantification of phenolic compounds. Regarding phenolic compounds, their loss was verified during storage, and was more pronounced in films with a higher percentage of propolis. The study also showed that, of the three groups of phenolic compounds (hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids), hydroxycinnamic acids showed the most significant losses. Overall, this study reveals the potential of using HPMC/propolis films as a coating for cheese in terms of microbiological control and the preservation of physicochemical properties.

Research of the properties of protein hydrolysates obtained from the broiler chicken gizzards as a potential component of bioactive film coatings

Protein hydrolysates are a promising active component in the production of bioactive film coatings for food products. Some biopolymers can exert the biological activity. More often, however, it is necessary to select biologically active substances to impart these properties to films. On the other hand, not all components allow forming films with the required properties, and therefore there is a need to study the individual technological characteristics of the components used. The purpose of the research is to establish the antioxidant and technological properties of protein hydrolysates obtained by microbial fermenta- tion of poultry by-products in whey with bifidobacteria, propionic acid bacteria and acidophilic bacteria as a potential basis for bioactive film coatings of food products. The hydrolysate obtained by fermentation without the addition of the specified bacterial species was used as a control sample. The functional properties of protein hydrolysates were assessed: antioxidant capacity by coulometric titration on an Expert-006 coulometer using ascorbic acid as a standard, antiradical activity by the DPPH method on a Jenway 6405 UV/Vis spectrophotometer with determination of the IC50 value. The technological proper- ties, solubility, water-holding, fat-holding and fat-emulsifying capacities were also determined by the gravimetric method. In addition, the average hydrodynamic diameter of particles in protein hydrolysates was determined using a Microtrac FLEX particle size analyzer. The results of studies of the antioxidant properties showed that the DPPH antiradical activity was 14.7% higher in the experimental samples of hydrolysates obtained by fermentation with bifidobacteria compared to the control; samples of hydrolysates obtained by fermentation with propionic acid bacteria showed an antioxidant capacity 29.6% higher than that of the control sample. The IC50 value turned out to be the highest in the control hydrolysate sample (2.994 mg/ml), which was 45.5–53.3% higher than that in the experimental hydrolysate samples. The results of determining the technologi- cal properties showed that they differ significantly for protein hydrolysates obtained by fermentation with different types of bacteria. For example, the highest values of fat-holding and fat-emulsifying capacities were found in the hydrolysate obtained by fermentation with bifidobacteria (351.1% and 61%, respectively), which shows its potential for incorporation into the bio- composite in the form of a protein-oil emulsion. The high solubility of the experimental samples of hydrolysates (from 90.1 to 91.4%) suggests their uniform distribution in the aqueous phase when composing the biocomposite of the film. Thus, the research results have shown the prospects of using protein hydrolysates from the gizzards of broiler chickens in whey as an active component of bioactive film coatings. The antioxidant properties of protein hydrolysates allow slowing down oxidative processes in the main food nutrients, which will contribute to an increase in the shelf life of food products packaged in bioac- tive films with this component.

Nanomechanical and Microstructural Characterization of Biocompatible Ti3Au Thin Films Grown on Glass and Ti6Al4V Substrates.

Ti-Au intermetallic-based material systems are being extensively studied as next-generation thin film coatings to extend the lifetime of implant devices. These coatings are being developed for application to the articulating surfaces of total joint implants and, therefore, must have excellent biocompatibility combined with superior mechanical hardness and wear resistance. However, these key characteristics of Ti-Au coatings are heavily dependent upon factors such as the surface properties and temperature of the underlying substrate during thin film deposition. In this work, Ti3Au thin films were deposited by magnetron sputtering on both glass and Ti6Al4V substrates at an ambient and elevated substrate temperature of 275 °C. These films were studied for their mechanical properties by the nanoindentation technique in both variable load and fixed load mode using a Berkovich tip. XRD patterns and cross-sectional SEM images detail the microstructure, while AFM images present the surface morphologies of these Ti3Au thin films. The biocompatibility potential of the films is assessed by cytotoxicity tests in L929 mouse fibroblast cells using Alamar blue assay, while leached ion concentrations in the film extracts are quantified using ICPOEMS. The standard deviation for hardness of films deposited on glass substrates is ∼4 times lower than that on Ti6Al4V substrates and is correlated with a corresponding increase in surface roughness from 2 nm for glass to 40 nm for Ti6Al4V substrates. Elevating substrate temperature leads to an increase in film hardness from 5.1 to 8.9 GPa and is related to the development of a superhard β phase of the Ti3Au intermetallic. The standard deviation of this peak mechanical hardness value is reduced by ∼3 times when measured in fixed load mode compared to the variable load mode due to the effect of nanoindentation tip penetration depth. All tested Ti-Au thin films also exhibit excellent biocompatibility against L929 fibroblast cells, as viability levels are above 95% and leached Ti, Al, V, and Au ion concentrations are below 0.1 ppm. Overall, this work demonstrates a novel Ti3Au thin film system with a unique combination of high hardness and excellent biocompatibility with potential to be developed into a new wear-resistant coating to extend the lifetime of articulating total joint implants.