Coating Technique Research Articles

Cell Membrane-Coated Nanoparticles for Precision Medicine: A Comprehensive Review of Coating Techniques for Tissue-Specific Therapeutics.

Nanoencapsulation has become a recent advancement in drug delivery, enhancing stability, bioavailability, and enabling controlled, targeted substance delivery to specific cells or tissues. However, traditional nanoparticle delivery faces challenges such as a short circulation time and immune recognition. To tackle these issues, cell membrane-coated nanoparticles have been suggested as a practical alternative. The production process involves three main stages: cell lysis and membrane fragmentation, membrane isolation, and nanoparticle coating. Cell membranes are typically fragmented using hypotonic lysis with homogenization or sonication. Subsequent membrane fragments are isolated through multiple centrifugation steps. Coating nanoparticles can be achieved through extrusion, sonication, or a combination of both methods. Notably, this analysis reveals the absence of a universally applicable method for nanoparticle coating, as the three stages differ significantly in their procedures. This review explores current developments and approaches to cell membrane-coated nanoparticles, highlighting their potential as an effective alternative for targeted drug delivery and various therapeutic applications.

Deposition and characterization of high velocity oxy‐fuel sprayed nickel chrome boron silicium based coatings on stainless steel substrates

AbstractAfter plasma spraying, high‐velocity‐oxy‐fuel (HVOF) spraying is fast emerging as the most versatile deposition technique for thermal sprayed protective coatings. In this context, the present work aims at the deposition of a class of inter‐metallic/cermet coatings of nickel chrome boron silicium (NiCrBSi) and nickel chrome boron silicium+titanium diboride (TiB2) on 304 stainless steel substrates using high‐velocity oxy‐fuel spraying route. The cermet powder is prepared as the feedstock by mechanical mixing of the powders prior to spraying. Different coating samples are obtained by varying the flame‐to‐substrate spray distance (40 mm, 80 mm, 120 mm, 160 mm and 200 mm). These coatings are characterized in terms of their adhesion strength, deposition efficiency, thickness, and micro‐hardness by conducting tests as per the ASTM standards. The surface and interface morphologies of the deposited coatings are studied using scanning electron microscopy. The possible phases present in the coatings, and the transformation of phases during deposition have been explored by x‐ray diffraction analysis. It is found that the coatings exhibit fairly good interfacial adhesion, micro‐hardness, and thickness values that varied significantly with the spray‐distance. Further, the premixing of titanium diboride in nickel chrome boron silicium improved the mechanical and microstructural/compositional properties of the coatings.

LiFePO4-coated carbon fibers as positive electrodes in structural batteries: Insights from spray coating technique

This study presents the fabrication of LiFePO4 (LFP)-coated carbon fibers (CFs) as a positive electrode component for structural batteries, utilizing a spray coating technique. The successful coating of CFs through this method demonstrated their usefulness as efficient current collectors. The electrodes obtained using this method underwent electrochemical evaluations. Throughout the extended cycling tests at C/7, the maximum specific discharge capacity reached 146 mAh/g, maintaining a 77% capacity retention after 100 cycles. In rate performance assessments at the faster C-rate of 1.5C, the capacity measured 123 mAh/g, with a retention of 96%. The application of spray coating emerges as a promising technique for electrode production in structural batteries, showcasing its potential for optimizing performance in multifunctional energy storage systems.

Femtosecond laser ablation (fs-LA) XPS – A novel XPS depth profiling technique for thin films, coatings and multi-layered structures

Sputter depth profiling has been employed for XPS/AESdepth profilingsincethe late 1960s. However, for many materials, ion beam induced damage distorts the chemical state information and chemical composition, limiting the value of the analysis. A novelmethodology is presented in which XPS depth profiles are generated using a 160 fs pulse length, 1030 nm peak wavelength femtosecond laser in place of the traditional ion gun. Femtosecond laser ablation (fs-LA) XPS depth profiles are compared with argon monatomic and cluster ion beam depth profilesfor different classes of materials, including ceramics, semiconductors, polymers and metals. In all cases, the XPS spectra recorded following femtosecond laser ablation are fully representative of the original chemical composition and chemical state, with no ablation induced damage. The technique is also shown to be very versatile with ablation rates of <20 nm per pulse being achieved for thin films but profiles to depths of >30 μm are also realisable in practical time scales.fs-LA XPS depth profiling promises to be a very exciting new methodology for the XPS community, complementing sputter depth profiling but avoiding the chemical damage induced by ion beams and offering valuable new depth profiling capabilities.

Correction: Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Correction: Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

HVOF THERMAL SPRAYING METHOD-PROPERTIES, CHALLENGES, AND OPPORTUNITIES IN BOILER/TURBINE APPLICATIONS: A REVIEW

The technique of thermal spray proves invaluable in helping to enhance the surface of solid materials. This specially and versatile process finds application in coating various materials and components, endowing them with increased resistance against wear, erosion, corrosion, abrasion, or heat. Highvelocity oxygen fuel (HVOF) coating is included in the category of most rapidly utilized coating techniques and is very good for making dense coatings at moderate temperatures, boasting reduced porosity (typically &amp;#60; 1&amp;#37;). Industries worldwide have broadly implemented HVOF because of its numerous benefits. This research article offers a comprehensive overview of numerous thermal spray coating techniques, and characteristics are outlined, showcasing the purpose of HVOF deposition in safeguarding materials from deterioration at elevated heat levels in extremely diverse environments. The article also focuses on previous research efforts in the surrounding context of HVOF-sprayed coatings techniques, challenges, advancements, and opportunities in boiler/turbine applications.

Trypanosome Infection in Cattle and Associated Vectors in Etang District of Gambella, Ethiopia.

Bovine trypanosomosis produces significant economic losses due to anemia, loss of body condition, and emaciation. The disease is transmitted biologically by tsetse flies and mechanically by biting flies such as Tabanus and Stomoxys. Therefore, this research is aimed at estimating the prevalence of bovine trypanosomosis and the apparent density of its vectors in the Etang Special District. A cross-sectional study was employed from November 2016 to April 2017 for the prevalence and entomological survey. Trypanosoma species were identified using buffy coat and Giemsa staining techniques. Besides, the entomological surveys were conducted using NGU, pyramidal, biconical, and monoconical traps. The vectors were identified to their genus level based on their morphological features like size, color, wing venation, and proboscis. A total of 457 bovine blood samples were collected and tested, of these 16 (3.50%) animals were positive for trypanosomosis. Similarly, 13 T. vivax (81.25%) and 3 T. congolense (18.75%) were the trypanosome species detected. The prevalence in the young (2.56%) and adult (3.99%) age groups was not statistically significant (P > 0.05). However, there were significant (P < 0.05) differences in prevalence between body condition scores, where poor is 6.31%, medium is 1.30%, and good is 0%. Moreover, the difference in mean PCV values between the parasitemic (20.97) and aparasitemic (28.58) groups was statistically significant (P < 0.05). Glossina flies were not found, although 1756 Tabanus and 52 Stomoxys biting flies were gathered. Accordingly, the overall apparent density of Glossina flies was zero (0), with biting flies (20.54) recorded per trap per day. Moreover, the apparent density of Tabanus and 52 Stomoxys was 39.01 and 1.18, respectively. This study confirmed that trypanosomosis and abundant mechanical vectors continue to be problems in the study area, resulting in cattle productivity losses. As a result, strategic management and prevention methods for trypanosomosis and associated vectors should be prioritized. Further investigation of vector needs to be conducted to clear out tsetse presence.

Animal trypanosomosis eliminated in a major livestock production region in Senegal following the eradication of a tsetse population.

African animal trypanosomosis (AAT) was one of the main disease-related constraints to the development of intensive livestock production systems in the Niayes region of Senegal, a 30km wide strip of land along the coast between Dakar and Saint-Louis. To overcome this constraint, the Government of Senegal initiated an area-wide integrated pest management programme combining chemical control tactics with the sterile insect technique to eradicate a population of the tsetse fly Glossina palpalis gambiensis Vanderplank, 1949 (Diptera, Glossinidae) in this area. The project was implemented following a phased conditional approach, and the target area was divided into three blocks treated sequentially. This study aims to assess the temporal dynamics of the prevalence of Trypanosoma spp. during the implementation of this programme. Between 2009 and 2022, 4,359 blood samples were collected from cattle and screened for trypanosomes using both the buffy coat and ELISA techniques, and PCR tests since 2020. The seroprevalence decreased from 18.9% (95%CI: 11.2-26.5) in 2009 to 0% in 2017-2022 in block 1, and from 92.9% (95%CI: 88.2-97) in 2010 to 0% in 2021 in block 2. The parasitological and serological data confirm the entomological monitoring results, i.e., that there is a high probability that the population of G. p. gambiensis has been eradicated from the Niayes and that the transmission of AAT has been interrupted in the treated area. These results indicate the effectiveness of the adopted approach and show that AAT can be sustainably removed through the creation of a zone free of G. p. gambiensis.

Formation of Quaternary Czt(S,Se) Compounds Using Hydrothermal Synthesis and Spin Coating Technique

Formation of Quaternary Czt(S,Se) Compounds Using Hydrothermal Synthesis and Spin Coating Technique

Sensitive and Repeatable Optical Fiber Hydrogen Sensors Using Plasma-induced Oxygen Vacancies Magnetron Sputtering Coating Technique

Sensitive and Repeatable Optical Fiber Hydrogen Sensors Using Plasma-induced Oxygen Vacancies Magnetron Sputtering Coating Technique

Towards Conformally Grafted Thin Film Ionomers for High Performance Polymer Electrolyte Fuel Cells

The development of the next generation of polymer electrolyte fuel cells has become a major focus in the decarbonization of heavy-duty transportation, such as public transport, land, aviation, and maritime freight1. Specifically, there is a need for improved catalyst layers with lower amounts of expensive platinum group metals2, as well as improved mass transport characteristics at high current densities, fluorine-free ionomers, and increased durability3. Achieving an optimal electrode microstructure is crucial in this process, as it influences the mass transport of reactant gases and products2. The chemistry and morphology of the ionomer film determine proton availability and affect oxygen transport and overall catalyst utilization. Thus, it is critical to maintain a delicate balance between the transport of reactants, products, protons, and electrons to ensure optimal cell performance. Traditional catalyst layers are fabricated using catalyst ink dispersions which limits the control over the triple-phase boundary microstructure4. This is problematic as poor distribution of the ionomer has been shown to have a negative impact on fuel cell performance5. It has been observed that some catalytic sites are inundated with ionomer, leading to a high oxygen transport resistance, while other uncoated sites may experience a lack of protons. Moreover, research has shown that the catalyst's active sites can be poisoned by the adsorption of sulfonic acid moieties present in commonly used ionomers. Motivated by these challenges, and the negative environmental impact of conventional fluorinated ionomers, it is essential to develop alternative ionomer chemistries and coating techniques6.To address these challenges, our research focuses on developing innovative synthetic methods that leverage both electrochemical and chemical principles to enable local control of ionomer coating in the catalyst layer. Our interest in these methods originates from their scalability and ability to control the morphology of coatings (e.g. thickness, conformality, porosity and polymer length). We employ grafting techniques based on radical mechanisms to covalently graft conformal ionomer thin films onto conventional Pt/C catalysts to produce improved triple phase boundaries. A vast array of monomers with different kinds of functionalities (e.g. amines, vinylics, diazo-compounds, carboxylates) can be used for grafting, including fluorine-free systems7. In this presentation, I will first describe the synthetic procedure to produce ionomer thin films. Second, we perform ex-situ characterization including electron microscopy, porosimetry and wettability measurements. Furthermore, we study the ionomeric nature of the films by its ion exchange capacity. Subsequently, we screen the most promising samples in single cell tests and compare them against a state-of-the-art benchmark. By combining potentiostatic and impedance-based techniques, we seek to gain insight into the in-operando characteristics of these new electrode materials. Through this comprehensive set of experiments, we aim to elucidate morphology – property – performance relationships for these ionomer thin films to further guide optimization of catalyst microstructures. Acknowledgement: This publication is part of the project 3D-FCoat (3-Dimensional structures for Fuel Cells through advanced Coating techniques) of the research program LIFT which is (partly) financed by the Dutch Research Council (NWO) and Nedstack Fuel Cell Technology B.V.

Polluted Water Sensor Based on Carbon Quantum Dots/Alq3 Using Drop Casting and Spin Coating Techniques

Water quality sensors have recently received a lot of attention due to their impact on human health. Due to their distinct features, environmental sensors are based on carbon quantum dots (CQDs). In this study, CQDs were prepared using the electro-chemical method, where the structural and optical properties were studied. These quantum dots were used in the environmental sensor application after mixing them with three different materials: CQDs, Alq3 polymer and CQDs and Alq3 solutions using two different methods: drop casting and spin coating, and depositing them on silicon. The sensitivity of the water pollutants was studied for each case of the prepared samples after measuring the change in resistance of the samples at a temperature of 30 oC. Through the results, it was found that the highest sensitivity of sample 3 to the carbon continuous dot was in the case of the contaminant fructose and was 99.55%, while the highest sensitivity of sample 4 was for the one sensitive to the contaminant (mercury chloride) and was 81. As for sample 1, the highest sensitivity was in the case of detecting the contaminant lead chloride and was 80. The results showed that the best sensor was obtained using a spin-coating technique when the solution sample of CQDs+Alq3 was placed on a silicon slide in fructose and the sensitivity was 200%. This demonstrates the importance of quantum dots in measuring the sensitivity of water pollutants. The thin film thickness was measured to be 500 nm.

Advances in Corrosion Mitigation for Waste-to-Energy Systems: Evaluating Coatings and Application Techniques

Waste-to-Energy (WTE) systems, utilizing post-recycled municipal solid waste (MSW) and other biomass materials, are proven alternatives to landfilling for sustainable waste management. These processes offer benefits such as reduced landfill space, decreased methane emissions, and minimized waste volume. However, operational challenges, specifically high-temperature corrosion (HTC) of superheater tubes, hinder their efficiency due to the presence of chlorine, alkaline salts, and sulfates. To address this issue, a range of coating techniques have been developed, with thermal spray techniques, particularly high velocity oxy-fuel (HVOF) spray, proving the most effective for protecting superheater tubes. A comparative analysis of experimental data from multiple studies indicates that coatings with Alloy 625, Alloy C-276, Colmonoy 88, FeCr, IN625, NiCr, NiCrTi, and A625 offer high corrosion resistance at relatively low material costs, with corrosion rates below 1 mm/year. High chromium, nickel, and molybdenum content coatings perform exceptionally well under high-temperature and high-chlorine conditions. Notably, T92 and P91, due to their low cost and high corrosion resistance, are strong candidates for superheater tubes operating at 550°C. While A625 demonstrates excellent corrosion resistance, its high cost limits its practicality. Ultimately, the selection of suitable coatings depends on the specific WTE plant design and operating experience. The additional cost of applying these coatings is a minor fraction of the overall financial gains, as it extends the superheater tubes' lifetime and reduces plant downtime for tube repair or replacement.

Paper Coatings Based on Polyvinyl Alcohol and Cellulose Nanocrystals Using Various Coating Techniques and Determination of Their Barrier Properties

The goal of this work was to improve the barrier properties of selected papers against water, grease and oil or gases (water vapor and oxygen) by covering them with biodegradable commercial coating carriers based on cellulose nanocrystals (CNCs) and polyvinyl alcohol (PVOH). The aim was also to obtain cellulose recyclable packaging materials with improved barrier characteristics. The properties of paper coatings based on CNCs and PVOH were characterized. Various paper coating techniques (flexographic printing, rotogravure printing and blade printing) were evaluated with respect to the final properties of the surface-modified paper with different starting grammages (40 g/m2, 70 g/m2, 100 g/m2). Functional properties, such as the barrier against oxygen, water vapor, water and grease; mechanical properties; and seal characterization of coated paper were examined. The results of this study demonstrated that the covering of the paper may improve the water, grease and oil barrier and that the best results were obtained for Gerstar 70 g/m2 coated with J12 coatings using the flexographic technique.

Performance of diagnostic tests for Trypanosoma brucei brucei in experimentally infected pigs.

Animal African trypanosomosis is an important vector-borne disease of livestock in sub-Saharan Africa. Pigs seem relatively tolerant to trypanosome infection and could act as a reservoir of trypanosomes affecting animals and humans. Our ability to reliably detect trypanosome infection in pigs depends on the performance of diagnostic tools, which is not well known. In pigs experimentally infected with Trypanosoma brucei brucei, we evaluated the performance of parasitological Buffy Coat Technique (BCT), two molecular (TBR and 5.8S PCR) and four serological tests (CATT, HAT Sero-K-Set rapid diagnostic test-RDT, indirect ELISA, immune trypanolysis). Most diagnostic tests showed high specificity, estimated at 100% (95% CI = 74-100%) with the exception of CATT and RDT whose specificity varied between 100% (95% CI = 74-100%) to 50% (95% CI = 7-93%) during the experiment. The sensitivity of each test fluctuated over the course of the infection. The percentage of positive BCT over the infection (30%) was lower than of positive PCR (56% and 62%, depending on primers). Among the serological tests, the percentage of positive tests was 97%, 96%, 86% and 84% for RDT, ELISA, immune trypanolysis and CATT, respectively. Fair agreement was observed between both molecular tests (κ = 0.36). Among the serological tests, the agreement between the ELISA and the RDT was substantial (κ = 0.65). Our results on the T.b. brucei infection model suggest that serological techniques are efficient in detecting the chronic phase of infection, PCR is able to detect positive samples several months after parasites inoculation while BCT becomes negative. BCT examination and RDT are useful to get a quick information in the field, and BCT can be used for treatment decision. ELISA appears most suited for epidemiological studies. The selection of diagnostic tests for trypanosomosis in pigs depends on the context, the objectives and the available resources.

Solid Lubrication System and Its Plasma Surface Engineering: A Review

In aerospace, aviation, nuclear power, and other high-tech fields, some essential moving parts must operate under high vacuum, high load, intense radiation, and other conditions. Under such extreme conditions, only solid lubricating materials can meet the lubrication requirements. Traditional material modification methods have problems such as high energy consumption, severe pollution, and narrow scope of application. Plasma modification technology can overcome these shortcomings. This paper focuses on several commonly used plasma preparation techniques for solid lubricating coatings, including plasma chemical heat treatment, physical vapor deposition, plasma immersion ion implantation and deposition, plasma spraying, and plasma electrolytic oxidation. Subsequently, the material systems of metal-based solid lubrication coatings are reviewed: soft metals, oxides, sulfides, nitrides, and carbon-based materials. Finally, found that the development of new solid lubricants, the improvement of existing preparation technology, and the development of new processes are the key development directions in the future.

Ca-Doped Copper (I) Oxide Deposited via the Spray Coating Technique for Heterojunction Solar Cell Application

In this report, the morphological, optical, electrical, and photovoltaic properties of copper oxide and calcium-doped copper oxide thin films produced via the spray coating method were studied. The thermal post treatment at 300 °C in an inert atmosphere allowed us to obtain a single phase of Cu2O with 21 Ωcm of resistivity (ρ). In this study, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, and 10 wt% Ca admixtures with copper oxide were investigated. The determined optimal calcium dopant concentration was 4 wt%. XRD analysis was used to reveal the chemical composition of the produced layers. It was found that a calcium dopant does not change the layer composition but improves its electrical parameters. Based on UV-Vis spectra, the band gap energy and Urbach energy were calculated. The morphology of produced thin films was described as smooth and nanocrystalline, corresponding to a grain size calculated based on the Scherrer equation. Finally, it was shown that the developed protocol of low-resistivity copper oxide deposition via the spray coating technique can be successfully implemented in heterojunction solar cell production. The I–V parameters of Ag/n-type CzSi/REF:CuOx and 4Ca:CuOx/Carbon were collected, and the achieved efficiency was 2.38%.

Synthesis of Copper Nanosheets Coatings onto Glass and Glass/CrSe2 Substrates Using Ion Coating Technique for Terahertz Technology

AbstractIn this study, copper (Cu) nanosheets are utilized as semitransparent conducting optical windows for the fabrication of terahertz band filters based on chromium selenide (CrSe2). The deposition of CrSe2 thin films onto glass substrates is performed via the thermal evaporation technique followed by the application of Cu nanosheets using the ion coating technique. The interaction between Cu windows and CrSe2 films resulted in a slight widening of the energy bandgap and a remarkable reduction in the Urbach tail states from 2.24 to 1.23 eV. Furthermore, the coating of CrSe2 with Cu optical windows led to a decrease in the dielectric constant values of more than 35% and an increase in the terahertz cutoff frequency by more than 70%. The application of Cu windows increased the cutoff frequency to 23 THz. The correlation between electrical and optical conduction in the terahertz band filters is investigated through the utilization of Drude–Lorentz models, revealing that although Cu windows reduced the free carrier density and conductivity, they enhanced drift mobility, resulting in more efficient terahertz filter properties. The calculated optical constants and optical conductivity parameters provided evidence of the suitability of Cu‐coated CrSe2 films for applications in terahertz technology.

Prevalence of Bovine Trypanosomosis and Density of Tsetse Fly in Duguna Fango District, Wolaita Zone, Southern Ethiopia

A cross-sectional study was conducted from December 2017 to April 2018 in Diguna Fango district in Wolaita zone, Southern Ethiopia, with the objectives to determine the prevalence of bovine trypanosomosis and to assess the distribution and apparent densities of vectors of the trypanosomosis. A parasitological study using buffy coat technique was employed for the determination of prevalence of trypanosomosis while monoconical traps were used for the vector studies. A total of 192 cattle randomly selected from the study population were examined for the parasitological study. The result of parasitological study revealed that the overall prevalence of trypanosomosis was found to be 7.3% in Duguna Fango district. The prevalence showed no significant difference in susceptibility between sex categories and in age groups (P&gt;0.05). From the infected animals the prevalence for trypanosome species was 14.3% and 85.7% for T. vivax and T. congolense, respectively. The mean PCV values of parasitaemic and aparasitaemic animals were 19.7% and 25.7, respectively. About 20 monoconical traps in two kebele (Bilate and Anka) of Duguna Fango districts were deployed for 72 hours with odour attractants for the vector studies. There were 22 G. pallidipes and 43 tabanus had been collected from the study site with the respective density of 1.1 and 2.15 fly/trap/day. Therefore, implementing control of trypanosomosis with an integrated approach was paramount importance in areas of the study site.

3,4-Dihydroxiphenylacetic Acid-Based Universal Coating Technique for Magnetic Nanoparticles Stabilization for Biomedical Applications.

Magnetic nanoparticles based on iron oxide attract researchers' attention due to a wide range of possible applications in biomedicine. As synthesized, most of the magnetic nanoparticles do not form the stable colloidal solutions that are required for the evaluation of their interactions with cells or their efficacy on animal models. For further application in biomedicine, magnetic nanoparticles must be further modified with biocompatible coating. Both the size and shape of magnetic nanoparticles and the chemical composition of the coating have an effect on magnetic nanoparticles' interactions with living objects. Thus, a universal method for magnetic nanoparticles' stabilization in water solutions is needed, regardless of how magnetic nanoparticles were initially synthesized. In this paper, we propose the versatile and highly reproducible ligand exchange technique of coating with 3,4-dihydroxiphenylacetic acid (DOPAC), based on the formation of Fe-O bonds with hydroxyl groups of DOPAC leading to the hydrophilization of the magnetic nanoparticles' surfaces following phase transfer from organic solutions to water. The proposed technique allows for obtaining stable water-colloidal solutions of magnetic nanoparticles with sizes from 21 to 307 nm synthesized by thermal decomposition or coprecipitation techniques. Those stabilized by DOPAC nanoparticles were shown to be efficient in the magnetomechanical actuation of DNA duplexes, drug delivery of doxorubicin to cancer cells, and targeted delivery by conjugation with antibodies. Moreover, the diversity of possible biomedical applications of the resulting nanoparticles was presented. This finding is important in terms of nanoparticle design for various biomedical applications and will reduce nanomedicines manufacturing time, along with difficulties related to comparative studies of magnetic nanoparticles with different magnetic core characteristics.