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14 pages, 2221 KiB

Open AccessArticle

Antifouling Performance and Long-Term Efficiency of a Zwitterionic Sulfobetaine-Hydroxyethyl-Containing Polymethylmethacrylate Ter-Co-Polymer Coating Against Biomass-Producing Photosynthetic Strains

by Rana Haider Ali, Vincenzo Zammuto, Marco Nicolò, Filomena De Leo, Sandra Lo Schiavo and Clara Urzì

Coatings 2025, 15(4), 462; https://doi.org/10.3390/coatings15040462 - 13 Apr 2025

Viewed by 348

Abstract

The antifouling performance of a zwitterionic sulfobetaine-hydroxyethyl-containing polymethylmethacrylate ter-co-polymer (PSBM) is evaluated against three photosynthetic strains, namely Chlorella sp., Nannochloropsis sp., and Arthrospira maxima. PSBM-coated polymethylmethacrylate (PMMA) surfaces displayed a significantly reduced propensity for biofilm formation compared to rough and untreated controls, [...] Read more.

The antifouling performance of a zwitterionic sulfobetaine-hydroxyethyl-containing polymethylmethacrylate ter-co-polymer (PSBM) is evaluated against three photosynthetic strains, namely Chlorella sp., Nannochloropsis sp., and Arthrospira maxima. PSBM-coated polymethylmethacrylate (PMMA) surfaces displayed a significantly reduced propensity for biofilm formation compared to rough and untreated controls, leaving clean surfaces after 7 days of exposure. A tribological approach was adopted to estimate the long-term durability of the PSBM coating. Repeated cycles of exposure to Chlorella sp., Nannochloropsis sp., and A. maxima biomass subject the coating to stress and continuous biofilm challenges. After several cycles, the PSBM coating maintains a higher antifouling efficacy than the untreated PMMA surface, suggesting stability and high potential in photobioreactor applications. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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15 pages, 5437 KiB

Open AccessArticle

Deposition and Characterization of Zinc–Tin Oxide Thin Films with Varying Material Compositions

by Stanka Spasova, Vladimir Dulev, Alexander Benkovsky, Vassil Palankovski, Ekaterina Radeva, Rumen Stoykov, Zoya Nenova, Hristosko Dikov, Atanas Katerski, Olga Volobujeva, Daniela Lilova and Maxim Ganchev

Coatings 2025, 15(2), 225; https://doi.org/10.3390/coatings15020225 - 13 Feb 2025

Viewed by 674

Abstract

Zinc–tin oxide (ZTO) thin films (ZnO)_x(SnO₂)_1−x with different material composition x (0 < x < 1) are deposited by spin coating on glass substrates at room temperature. The Differential Scanning Calorimetry (DSC) data of the precursor compounds show [...] Read more.

Zinc–tin oxide (ZTO) thin films (ZnO)_x(SnO₂)_1−x with different material composition x (0 < x < 1) are deposited by spin coating on glass substrates at room temperature. The Differential Scanning Calorimetry (DSC) data of the precursor compounds show gradual phase transitions up to 480 °C. These data are used for an appropriate regime for thermal annealing of the layers. X-ray photoelectron spectroscopy (XPS) data show mixed oxide compound formation in states Zn²⁺, Sn⁴⁺ and O²⁻ of the constituents. Optical investigation manifests high transmittance above 80% in the visible spectral range and an optical band gap of 3.3–3.7 eV. The work functions vary between 4.1 eV and 5 eV, depending on the annealing, with deviations less than 1% for surface 1 mm² scans. Stack devices ITO/ZTO/metal with different metal contacts are formed. The I–V (current–voltage) measurements of the fabricated stacks exhibit Ohmic or nonlinear behavior, depending on the material composition and the work function levels. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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11 pages, 3513 KiB

Open AccessArticle

Spraying Power Effect on Micro-Structure and Mechanical Property of TaSi₂ Coating Prepared by Supersonic Air Plasma Spraying for SiC-Coated C/C Composites

by Fei Liu, Hejun Li, Qiangang Fu, Bolun Ji, Lihao Chen, Bilin Zhang, Wei Zhang and Xinhai He

Coatings 2024, 14(10), 1268; https://doi.org/10.3390/coatings14101268 - 3 Oct 2024

Viewed by 863

Abstract

In order to further improve the oxidation resistance of SiC-coated C/C composites used in extreme environments, TaSi₂ coatings were deposited on the surfaces of SiC-coated C/C composites by supersonic air plasma spraying (SAPS) with different spraying power parameters, under other fixed parameter [...] Read more.

In order to further improve the oxidation resistance of SiC-coated C/C composites used in extreme environments, TaSi₂ coatings were deposited on the surfaces of SiC-coated C/C composites by supersonic air plasma spraying (SAPS) with different spraying power parameters, under other fixed parameter (gas flow, power feed rate, spraying distance and nozzle diameter) conditions. The micro-structures and phase characteristics of the TaSi₂ coatings prepared with the four kinds of spraying powers (40 kW, 45 kW, 50 kW and 55 kW) were analyzed. Also, the inter-facial bonding strengths and fracture modes between the four TaSi₂ coatings and the SiC coating were studied. The results showed that with an increase in the spraying power, the morphologies of the TaSi₂ coatings appeared from loose to dense to loose. When the spraying power was 50 kW, the deposition rate reached a maximum of 39.8%. The TaSi₂ coating presented an excellent micro-structure without obvious pores and microcracks, and its inter-facial bonding strength was 15.3 ± 2.3 N. Meanwhile, the fracture surface of the sample exhibited a brittle characteristic. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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18 pages, 3597 KiB

Open AccessArticle

Adsorption Study of Uremic Toxins (Urea, Creatinine, and Uric Acid) Using Modified Clinoptilolite

by Shirley Carro, Christian J. Cabello-Alvarado, Marlene Andrade-Guel, Juan Carlos Aguilar-Márquez, Pedro R. García-Morán, Carlos A. Avila-Orta and Zoe V. Quiñones-Jurado

Coatings 2024, 14(9), 1099; https://doi.org/10.3390/coatings14091099 - 1 Sep 2024

Viewed by 1702

Abstract

The development of materials for uremic toxin removal is under continuous research. In this work, a natural zeolite (clinoptilolite) was modified using tartaric acid through two different methods: conventional reflux heating and ultrasound energy. The resulting materials were used as an adsorbent material [...] Read more.

The development of materials for uremic toxin removal is under continuous research. In this work, a natural zeolite (clinoptilolite) was modified using tartaric acid through two different methods: conventional reflux heating and ultrasound energy. The resulting materials were used as an adsorbent material for the removal of uremic toxins such as urea, creatinine, and uric acid. In the uremic toxin removal study, it was observed that the material modified using ultrasound for 100 min had the highest removal values (74.49%, 40.31%, and 51.50% for urea, creatinine, and uric acid, respectively), while unmodified zeolite removed 30.57%, 18.07%, and 22.84% of the same toxins. The best results for conventional heating modification were 67.08%, 31.97%, and 32.39%, respectively. Therefore, acid group incorporation considerably improved the adsorption properties of the clinoptilolite. Regarding adsorption kinetics, it was found that the pseudo-second-order model better described the behavior of all the modified materials. Equilibrium adsorption data were adjusted to the Langmuir and Freundlich models. The Freundlich model (multilayer adsorption) described urea adsorption, while the Langmuir model (monolayer adsorption) described creatinine and uric acid. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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25 pages, 11956 KiB

Open AccessArticle

Innovative Paper Coatings: Regenerative Superhydrophobicity through Self-Structuring Aqueous Wax-Polymer Dispersions

by Cynthia Cordt, Jennifer Daeg, Oliver Elle, Andreas Geissler and Markus Biesalski

Coatings 2024, 14(8), 1028; https://doi.org/10.3390/coatings14081028 - 13 Aug 2024

Cited by 4 | Viewed by 2710

Abstract

For a wide range of applications, paper materials require effective protection against the destructive effect of water, which is most effectively realized by superhydrophobic coatings. In recent years, a considerable amount of scientific research has been carried out in this area, focusing particularly [...] Read more.

For a wide range of applications, paper materials require effective protection against the destructive effect of water, which is most effectively realized by superhydrophobic coatings. In recent years, a considerable amount of scientific research has been carried out in this area, focusing particularly on biogenic resources. With this contribution, we go one step further and examine how biogenic materials can be transferred into aqueous dispersions and coated onto paper via existing technologies. With this paper coating, based on a hydrophobic cellulose derivative in combination with a structurally similar wax, thermally regenerable flower-like surface morphologies are obtained via self-assembly, where the hydrophobic cellulose polymer acts as a structural template for the co-crystallization of the wax component. Such hydrophobic structures in the low micrometer range ensure perfectly water-repellent paper surfaces with contact angles > 150° starting from coating weights of 5 g/m². The dispersion can be successfully applied to a variety of commercially available paper substrates, whereby the effects of different roughness, porosity, and hydrophobicity were investigated. In this context, a certain roughness of the base paper (S_a ~ 1.5–3 µm) was found to be beneficial for achieving the highest possible contact angles. Furthermore, the approach proved to be paper process-compatible, recyclable, and regenerable, whereby the processing temperatures allow the coating properties to be thermally generated in situ. With this work, we demonstrate how biogenic waxes are very well suited for superhydrophobic, regenerative coatings and, importantly, how they can be applied from aqueous coatings, enabling simple transfer into the paper industry. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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17 pages, 11380 KiB

Open AccessArticle

An Experimental Study Based on Surface Microtexture of Medical Devices

by Chaoda Chen, Xiaoqiang Shao, Junrong Guo, Zhuoyuan Yu, Ziyang Chen, Xuan Lu and Zhansi Jiang

Coatings 2024, 14(7), 888; https://doi.org/10.3390/coatings14070888 - 17 Jul 2024

Cited by 1 | Viewed by 868

Abstract

Surface microstructures formed by jet electrolytic processing are widely used in aerospace and biomedical applications, and their unique process has an important role in medical devices. To improve the precision and usability of medical devices processed using this process, electrolytic characterization and micropit [...] Read more.

Surface microstructures formed by jet electrolytic processing are widely used in aerospace and biomedical applications, and their unique process has an important role in medical devices. To improve the precision and usability of medical devices processed using this process, electrolytic characterization and micropit morphology experiments under different processing parameters were carried out to study the effect of EJM processing on processing efficiency and processing quality. The influencing factors of electrolytic machining rate were deduced by electrochemical theory, the electric field simulation was carried out using Comsol to analyze the electric field distribution and current density profile in the micropit, and the actual machining micropit was measured using a scanning microscope. The experiments show that increasing the peak voltage, reducing the machining gap, and extending the machining time can increase the depth of the micropit by 20%–40% and reduce the height of the silo by 45%–65%, which can effectively improve the surface structure of the medical device. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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19 pages, 8413 KiB

Open AccessArticle

Photocatalytic Activity and Antibacterial Properties of Mixed-Phase Oxides on Titanium Implant Alloy Substrates

by Haden A. Johnson, Darby Donaho, Aya Ali, Amisha Parekh, Randall S. Williamson, Mary E. Marquart, Joel D. Bumgardner, Amol V. Janorkar and Michael D. Roach

Coatings 2024, 14(5), 595; https://doi.org/10.3390/coatings14050595 - 9 May 2024

Viewed by 1326

Abstract

Titanium alloys are commonly used for implants, but the naturally forming oxides are bioinert and not ideal for bacterial resistance or osseointegration. Anodization processes are a modification technique that can crystallize the oxides, alter oxide surface topography, and introduce beneficial chemistries. Crystalline titanium [...] Read more.

Titanium alloys are commonly used for implants, but the naturally forming oxides are bioinert and not ideal for bacterial resistance or osseointegration. Anodization processes are a modification technique that can crystallize the oxides, alter oxide surface topography, and introduce beneficial chemistries. Crystalline titanium oxides are known to exhibit photocatalytic activity (PCA) under UVA light. Anodization was used to create mixed-phase oxides on six titanium alloys including commercially pure titanium (CPTi), Ti-6Al-4V (TAV), Ti-6Al-7Nb (TAN), two forms of Ti-15Mo (TiMo-β and TiMo-αβ), and Ti-35Nb-7Zr-5Ta (TNZT). Combined EDS and XPS analyses showed uptake of the electrolyte and substrate alloying elements into the oxides. The relative oxide PCA was measured using methylene blue degradation assays. CPTi and TAN oxides exhibited increased PCA compared to other alloys. Combined XRD and EBSD oxide phase analyses revealed an unfavorable arrangement of anatase and rutile phases near the outermost surfaces, which may have reduced PCA for other oxides. The relative Staphylococcus aureus attachment to each oxide was also assessed. The CPTi and TiMo-αβ oxides showed significantly reduced S. aureus attachment after 1 h of UVA compared to un-anodized CPTi. Cell culture results verified that the UVA irradiation did not negatively influence the MC3T3-E1 attachment or proliferation on the mixed-phase oxides. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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15 pages, 8536 KiB

Open AccessArticle

Excitation-Wavelength- and Time-Dependent Fluorescent Ink Based on RGB Building Blocks for Advanced Anti-Counterfeiting

by Chengxin Lin, Chenxi Kang, Xinxin He, Jiaci Yi and Qi Zhu

Coatings 2024, 14(4), 506; https://doi.org/10.3390/coatings14040506 - 19 Apr 2024

Cited by 2 | Viewed by 1586

Abstract

What is reported here is an advanced anti-counterfeiting ink whose luminous effect changes over time and at different excitation wavelengths. Unlike traditional anti-counterfeit fluorescent materials, the phosphors used here exhibit multicolor emissions under multiple excitation modes. In this work, the most important building [...] Read more.

What is reported here is an advanced anti-counterfeiting ink whose luminous effect changes over time and at different excitation wavelengths. Unlike traditional anti-counterfeit fluorescent materials, the phosphors used here exhibit multicolor emissions under multiple excitation modes. In this work, the most important building blocks are three classic phosphors with primary colors, red (Ca₂YNbO₆:0.4Eu³⁺), green (SrAl₂O₄:0.01Eu²⁺, 0.02Dy³⁺) and blue (CaAl₂O₄:0.012Eu²⁺, 0.06Nd³⁺, 0.036Gd³⁺), which were synthesized using the high-temperature solid-state method. The phosphors formed homogeneous solid solutions and were uniformly distributed throughout the mixture. A homogeneous transparent luminescent ink was obtained by blending the multi-mode phosphors with transparent screen-printing ink, resulting in multi-mode luminescence by simply varying the proportions of the red (R), green (G) and blue (B) phosphors. Thanks to this simple process, an advanced anti-counterfeiting ink with low production costs was achieved. Anti-counterfeiting logos of a “Giraffe” and “Steam Train” were printed using the transparent fluorescent ink onto black cardstock, exhibiting the characteristic of dynamic luminescence dependent on the duration and excitation wavelength. The anti-counterfeiting effect of the patterns suggests that the fluorescent ink is worth developing and is reliable in its application. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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12 pages, 3515 KiB

Open AccessArticle

Synthesis of an Epoxy Toughening Curing Agent through Modification of Terephthalic Acid Sludge Waste

by Jinhui Fu, Huixian Kong, Rentong Yu, Jinchun Tu, Qiang Wu, Mingyu Wang, Lina Niu and Kexi Zhang

Coatings 2024, 14(4), 503; https://doi.org/10.3390/coatings14040503 - 18 Apr 2024

Viewed by 1842

Abstract

Purified terephthalic acid (PTA) is widely used as a chemical raw material, with its production process resulting in significant compounds that generate a substantial amount of sludge waste annually. These compounds are known to possess active hydrogen. Utilizing this property, a novel approach [...] Read more.

Purified terephthalic acid (PTA) is widely used as a chemical raw material, with its production process resulting in significant compounds that generate a substantial amount of sludge waste annually. These compounds are known to possess active hydrogen. Utilizing this property, a novel approach for the treatment of PTA sludge waste was developed for its modification and re-use. This study focuses on the preparation of epoxy curing agents using PTA sludge-tank material. The modification of PTA sludge-tank material is achieved by using the one-pot method to investigate the toughening effect of home-made curing agents on epoxy resins and compare them with commercially available curing agents, and to analyze the mechanism of the structure of the curing agent on the material. The results showed that while the tensile strength of the experimental group was generally lower than that of the control group, the impact strength was significantly higher. Additionally, the hardness and tensile strength of the materials gradually decreased with an increase of the amount of hardener, while the elongation at break and impact strength increased. Notably, at a hardener amount of 35%, the elongation at break increased by 3.89%, and the tensile strength and impact strength reached 10.13 MPa and 42.86 kJ m⁻², respectively, demonstrating excellent toughness and strength characteristics. These findings testified the feasibility of modifying PTA sludge waste to prepare an epoxy toughening curing agent is not only feasible, but also significantly enhances the material’s toughness. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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11 pages, 6395 KiB

Open AccessArticle

A Method for Preparing Surface Sub-Microstructures on Sapphire Surfaces Using Femtosecond Laser Processing Technology

by Kaixuan Wang, Jun Chen, Yubin Zhang, Qingzhi Li, Feng Tang, Xin Ye and Wanguo Zheng

Coatings 2024, 14(4), 481; https://doi.org/10.3390/coatings14040481 - 14 Apr 2024

Cited by 3 | Viewed by 1644

Abstract

Femtosecond laser processing technology is an advanced sub-micro-processing technique that enables the non-contact processing of various materials. This technology can be used to apply sub-micro structures for purposes such as hydrophilicity enhancement, optical transmittance improvement, and photonics detection. However, when it comes to [...] Read more.

Femtosecond laser processing technology is an advanced sub-micro-processing technique that enables the non-contact processing of various materials. This technology can be used to apply sub-micro structures for purposes such as hydrophilicity enhancement, optical transmittance improvement, and photonics detection. However, when it comes to processing micro/nanostructures on highly brittle materials using femtosecond lasers, there are challenges such as low processing efficiency, generation of debris, and microcracking. In this paper, we propose a method called the out-of-focus femtosecond laser direct writing technique combined with wet etching. This method offers simplicity, speed, and flexibility in preparing dense, large-area sub-microstructured surfaces on the brittle material sapphire. Our detailed investigation focuses on the impact of laser processing parameters (direct writing period, distance of focusing, direct writing speed, etc.) on the sub-microstructures of Al₂O₃ surfaces. The results demonstrate that this method successfully creates embedded sub-microstructures on the sapphire surface. The microholes, with a diameter of approximately 2.0 μm, contain sub-micro structures with a minimum width of 250 ± 20 nm. Additionally, we conducted experiments to assess the optical transmittance of sapphire nanostructures in the range of 350–1200 nm, which exhibited an average transmittance of approximately 77.0%. The water contact angle (CA) test yielded a result of 52 ± 2°, indicating an enhancement in the hydrophilicity of the sapphire nanostructures with only a slight reduction in optical transmittance. Our efficient fabrication of sub-microstructures on the sapphire surface of highly brittle materials offers a promising method for the production and application of brittle materials in the field of micro-optics. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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14 pages, 8851 KiB

Open AccessArticle

Approach to Heterogeneous Surface Roughness Evaluation for Surface Coating Preparation

by Hana Vrbová, Milena Kubišová, Vladimír Pata, Jana Knedlová, Jakub Javořík and Barbora Bočáková

Coatings 2024, 14(4), 471; https://doi.org/10.3390/coatings14040471 - 12 Apr 2024

Cited by 2 | Viewed by 1269

Abstract

This paper focuses on evaluating the roughness of heterogeneous surfaces, aiming to interpret data effectively for thorough assessment. Previous research highlights the significant impact of surface roughness on final coatings. Beam-cutting machining generates surfaces with position-dependent roughness parameter changes. However, there is inconsistency [...] Read more.

This paper focuses on evaluating the roughness of heterogeneous surfaces, aiming to interpret data effectively for thorough assessment. Previous research highlights the significant impact of surface roughness on final coatings. Beam-cutting machining generates surfaces with position-dependent roughness parameter changes. However, there is inconsistency in the methods for investigating roughness in such surfaces, leading to the loss of crucial information and potentially inaccurate results. This could result in flawed coating preparation and subsequent defects. This paper proposes a suitable evaluation method involving an optical 3D profilometer and a stabilizing support system for reliable measurements. It provides a detailed description of the materials and methods used. The objective is to establish a more consistent and accurate approach to assessing roughness for coating preparation. Technical applications demonstrate up-to-fivefold fluctuations in surface topography parameters, as illustrated in this manuscript. Overall, this paper seeks to address these challenges and provide a robust framework for evaluating roughness in heterogeneous surfaces, thereby enhancing surface coating preparation processes. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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13 pages, 2463 KiB

Open AccessArticle

Enhancing Hydrophobic Properties in Olive Oil-Coated Papers through Thermal Treatment

by Amelia Loesch-Zhang, Tobias Meckel, Markus Biesalski and Andreas Geissler

Coatings 2024, 14(3), 364; https://doi.org/10.3390/coatings14030364 - 20 Mar 2024

Cited by 2 | Viewed by 2547

Abstract

Enhancing paper hydrophobicity is of key importance for many paper-based applications. Fatty acids or vegetable oils and their derivatives replace environmentally harmful conventional coating materials but still require challenging chemical reactions for covalent attachment onto paper. Here, we show that simple storage of [...] Read more.

Enhancing paper hydrophobicity is of key importance for many paper-based applications. Fatty acids or vegetable oils and their derivatives replace environmentally harmful conventional coating materials but still require challenging chemical reactions for covalent attachment onto paper. Here, we show that simple storage of olive oil-coated cotton linter paper at 70 °C and subsequent Soxhlet extraction is able to endow paper with hydrophobic properties, reaching water contact angles above 130°. In-depth chemical and morphological analytics show the relevance of temperature and air accessibility during the aging process compared with aging at ambient temperature and under the exclusion of oxygen, underlining the importance of assessing a coating’s long-term performance and stability under diverse storage conditions. Simple storage of vegetable oil-coated paper at elevated temperatures followed by extraction proves to be an easy way to produce stable covalently attached hydrophobic paper coatings with exceptionally low coating amounts. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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9 pages, 4055 KiB

Open AccessArticle

Aging Effect of Plasma-Treated Carbon Fiber Surface: From an Engineering Point

by Shiwen Wang, Yu Wang, Ming Gao and Yifan Huang

Coatings 2024, 14(1), 80; https://doi.org/10.3390/coatings14010080 - 6 Jan 2024

Cited by 4 | Viewed by 2068

Abstract

Dielectric barrier discharge (DBD) plasma surface modification has certain aging effect. This article studies the aging effect of plasma (DBD) on the surface modification of carbon fibers. The test results show that plasma (DBD) treatment reduces the impurity particles on the surface of [...] Read more.

Dielectric barrier discharge (DBD) plasma surface modification has certain aging effect. This article studies the aging effect of plasma (DBD) on the surface modification of carbon fibers. The test results show that plasma (DBD) treatment reduces the impurity particles on the surface of carbon fibers and makes the surface texture coarser. In addition, there is no significant change. After plasma (DBD) treatment, the content of C–O–C, C–O and C=O on the surface of carbon fibers increased from 3.20%, 7.76% and 1.64% to 7.06%, 21.50 and 6.08%, respectively. This is due to the high-energy particle bombardment of the fiber surface, which forms activated carbon atoms on the surface. The free electrons of these activated carbon atoms combine with ionized oxygen in the air. However, with the passage of time, the content of C–O–C, C–O and C=O gradually decreases to 3.31%, 8.57% and 1.77%, respectively. This is because some functional groups formed on the treated carbon fiber surface are not firmly bound, and some of these functional groups containing O₂ groups will combine with surrounding substances through irreversible chemical oxidation reactions to produce CO₂, which leaves the carbon fiber surface as a gas. The treated carbon fibers will immediately become hydrophilic, and the water contact angle decreases from 148.71° to 0°. With the passage of time, the water contact angle gradually increases to 118.16°, and the hydrophobicity recovers. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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Review

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13 pages, 250 KiB

Open AccessReview

Exploring the Potential of High-Power Impulse Magnetron Sputtering for Nitride Coatings: Advances in Properties and Applications

by Pooja Sharma, Hongbo Ju, Nuno Miguel Figueiredo and Fábio Ferreira

Coatings 2025, 15(2), 130; https://doi.org/10.3390/coatings15020130 - 23 Jan 2025

Viewed by 1336

Abstract

High-Power Impulse Magnetron Sputtering (HiPIMS) has emerged as an excellent technology for producing high-quality nitride coatings, such as aluminum nitride (AlN), titanium nitride (TiN), chromium nitride (CrN), and silicon nitride (SiN), and composite nitride coatings such as titanium aluminum nitride (TiAlN), TiAlNiCN, etc. [...] Read more.

High-Power Impulse Magnetron Sputtering (HiPIMS) has emerged as an excellent technology for producing high-quality nitride coatings, such as aluminum nitride (AlN), titanium nitride (TiN), chromium nitride (CrN), and silicon nitride (SiN), and composite nitride coatings such as titanium aluminum nitride (TiAlN), TiAlNiCN, etc. These coatings are known for their exceptional hardness, thermal stability, and corrosion resistance. These make them ideal for high-performance applications. HiPIMS distinguishes itself by generating highly ionized plasmas that facilitate intense ion bombardment, leading to nitride films with superior mechanical strength, durability, and enhanced thermal properties compared to traditional deposition techniques. Critical HiPIMS parameters, including pulse duration, substrate bias, and ion energy, are analyzed for their influence on enhancing coating density, adhesion, and hardness. The review contrasts HiPIMS with other deposition methods, highlighting its unique ability to create dense, uniform coatings with improved microstructures. While HiPIMS offers substantial benefits, it also poses challenges in scalability and process control. This review addresses these challenges and discusses hybrid, bipolar, and synchronized HiPIMS solutions designed to optimize nitride coating processes. Hybrid HiPIMS, for instance, combines HiPIMS with other sputtering techniques like DCMS or RF sputtering to achieve balanced deposition rates and high-quality film properties. Bipolar HiPIMS enhances process stability and film uniformity by alternating the polarity, which helps mitigate charge accumulation issues. Synchronized HiPIMS controls precise pulse timing to maximize ion energy impact and improve substrate interaction, further enhancing the structural properties of the coatings. Hence, to pave the way for future research and development in this area, insights of the HiPIMS have been presented that underline the role of HiPIMS in meeting the demanding requirements of advanced industrial applications. Overall, this review article comprehensively analyzes the recent strategies and technological innovations in HiPIMS and highlights the significant potential of HiPIMS for advancing the nitride coating field. Full article

(This article belongs to the Special Issue Trends in Coatings and Surface Technology, 2nd Edition)

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