Journal of Coatings Technology and Research最新文献

Wood superhydrophobicity is an advantageous characteristic for various industrial and mechanical applications. In this study, a superhydrophobic surface on veneer wood was achieved by grafting (1H,1H,2H,2H-perfluorodecyltriethoxysilane) fluorosilane molecules on its surface using a simple soaking technique at ambient conditions. The 24-h soaking time achieved the superhydrophobic surface with a contact angle > 150° when measured 1 week after soaking and was stable for up to 4 weeks. As weeks progressed, the 4-h and 8-h soaking showed improvement in water contact angle with the 8-h going as high as 166 ± 0.2°. The FTIR and Raman spectroscopy analyses on the veneer wood surface reveal the attachment of the OH bonds of the wood cellulose to the fluorosilane molecules. Secondary ion mass spectra (SIMS) show a uniformly distributed fluorine map confirming the formation of the low surface energy. The FTIR spectroscopy, Raman spectroscopy, and SIMS help elucidate the structure of the fluorosilane functionalization on veneer wood.

Polypyrrole (PPy) and polypyrrole doped with molybdate (PPy/MoO₄^2-) coatings were prepared in oxalic medium on iron at a current density of 1.5 mA.cm^-2. The presence of anions doped inside PPy coating was identified by SEM/EDS analysis, and the morphology of the coating was analyzed by scanning electron microscopy. The corrosion protection performance of the coatings was investigated with both electrochemical impedance spectroscopy (EIS) and open-circuit potential (OCP) in 3% NaCl solution. OCP results show that the protection time is improved up to 84 h for PPy/MoO₄^2- coating while it was only 42 h for PPy coating. A self-healing property of PPy/MoO₄^2--based films was observed on the OCP measurement with the fluctuation of the rest potential. EIS results show that the film capacitance C_f of the PPy/MoO₄^2- coating decreases continuously when immersion time increases to reach a value of 53.84 10^-6 F after 24 h and then increases. In parallel, the film resistance R_f increases when immersion time increases indicating better corrosion resistance of the iron by the PPy/MoO₄^2- coating.

Polyurethane (PU) is a high-performance coating widely used in various environmental conditions, including humid and extreme temperatures. Despite extensive research into PU-based superhydrophobic coatings, their practical use is often limited by complex preparation methods and insufficient mechanical durability. This study introduces a simple, cost-effective method for creating superhydrophobic nanocomposite coatings with enhanced anti-icing properties. By applying a straightforward one-step thermal treatment, silica nanoparticles were hydrophobically modified. These nanoparticles, combined with PTFE powder, were incorporated into PU to form a superhydrophobic coating. The coating was analyzed using scanning electron microscopy to investigate its micro-nano-structure, atomic force microscopy and a surface profilometer to assess surface roughness, and surface free energy measurements to evaluate the effectiveness of the hydrophobic modification. The resulting coating achieved an apparent water contact angle of 152° ± 1°, representing a 116% increase compared to pure PU, and a sliding angle (SA) of 7° ± 1°. This represents a significant improvement over pure PU. It also demonstrated adequate self-cleaning and anti-icing properties. Anti-icing performance was assessed by measuring the freezing times of supercooled water droplets, demonstrating the coating's ability to delay ice formation. Additionally, the incorporation of paraffin oil was found to enhance ice inhibition. Additionally, cross-cut tape tests confirmed good adhesion. These findings confirmed that the prepared superhydrophobic nanocomposite coating shows significant potential for practical applications, offering enhanced durability, performance, and anti-icing capabilities.

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Self-healing anticorrosion coatings are attractive for extending the service-life of metals, especially in marine environments. This work reports the novel self-healing coatings based on (2-mercaptobenzimidazole)-loaded carbon nanocages (MBI@CNCs) embedded in a polymethyl methacrylate (PMMA) matrix. The carbon nanocages (CNCs) as inhibitor carriers provide abundant channels for loading and releasing of 2-mercaptobenzimidazole (MBI). Nanocomposite coatings containing 12 wt.% MBI@CNCs deliver the optimal anticorrosion performance as well as excellent self-healing properties when applied to carbon steels. After scratching the coatings in a corrosive medium, MBI molecules are released from the coating. The corrosion inhibitor then reacts with the metal surface to form a passivation layer by coordination and electrostatic effect. The general strategy combining the one-pot synthesis of CNCs and loading with a corrosion inhibitor is conducive to large-scale production and practical application of self-healing anticorrosion coatings.

A series of small molecule urethane methacrylates were synthesized and used as reactive diluents for UV-curable polyester powder coatings. A UV-curable polyester oligomer was prepared and formulated with the reactive diluents and a photoinitiator package. Kinetics studies were carried out using photo-differential scanning calorimetry (photo-DSC). The influence that the reactive diluent concentration, UV-light intensity, temperature, and atmosphere had on the reaction kinetics was investigated. Crosslinked samples that were analyzed via DSC showed that the glass transition temperature correlated well with the extent of conversion. In general, lower curing temperatures (i.e., ≤ 80°C) significantly reduced the conversion and polymerization rate. However, the use of a mono-functional reactive diluent facilitated much higher conversions than the UV-curable polyester control, even at just 5 wt% loading level. These findings suggest that reactive diluents can be used to improve the low temperature cure capability of UV-curable polyester powder coatings.

Traditional antiicing systems, typically based on active methods, often require additional energy input or contribute to environmental pollution. Hence, there is a significant market demand for more environmentally friendly and passive solutions. This study explores the development of passive antiicing coatings with alternatives to the perfluoro compounds commonly used in epoxy composite coatings. Due to the environmental and health hazards of per- and polyfluoroalkyl substances (PFAS) compounds, this work presents an approach to exchange 3-(perfluorooctyl)-1,2-propenoxide by alternative additives such as 1,2-epoxyhexadecane, or 1-aminohexadecane, or 1-pentadecanecarboxylic acid. The influence of these additives on the properties of rough epoxy coating filled with micro- (SiO₂) and nano-particles (Al₂O₃), such as on surface wettability and antiicing properties (e.g., ice nucleation times or ice adhesion), was investigated. FTIR, TGA, DSC, CLSM, and SEM-EDS were used to characterize obtained coatings. The coating with the acid additive could be used as a viable alternative, although the large roughness heterogeneity of the coatings studied would still require further optimization.

In recent years, the ongoing development of the waterborne polyurethane (WPU) industry has resulted in its widespread application in adhesives, waterborne coatings, waterborne inks, and other sectors. To meet the required specifications of WPU, researchers have developed various modification techniques aimed at improving WPU performance. This paper provides an overview of the preparation principles and methods for WPU. It subsequently offers a comprehensive review of modification methods employed to improve WPU properties, including water resistance, heat resistance, mechanical properties, adhesion, and antimicrobial properties. These methods are broadly categorized into six types: crosslinking modification, acrylic modification, epoxy modification, organosilicon modification, organofluorine modification, and nanoparticle modification. Furthermore, the progress of WPU research in water-based inks for food and pharmaceutical plastic packaging printing has been analyzed. Additionally, the modification methods of WPU and the limitations of WPU in aqueous inks for plastic packaging printing were identified. Finally, the future development of WPU in aqueous inks for packaging printing was discussed. We believe that these research advancements will contribute to the enhancement of environmental safety for WPUs, address environmental pollution issues, and promote the use of eco-friendly water-based inks.

In this study, a UV-curable copper (Cu) paste with enhanced anti-oxidation properties was developed by incorporating polyvinylpyrrolidone (PVP) as a coating agent. The paste was screen-printed and subjected to intense pulsed light (IPL) sintering, a rapid and ambient-temperature processing technique. The PVP-coated Cu electrodes exhibited a specific resistivity of 12 µΩ·cm after three sintering cycles, along with a thermal conductivity of 60.87 W/m·K. This combination of low resistivity and high thermal conductivity underscores the potential for efficient thermal management in electronic applications. To further improve durability and oxidation resistance, anti-corrosion agents, including organic solderability preservative (OSP) and oleic acid, were applied. Lifetime testing under room temperature and high-humidity conditions (85 °C/85% RH) revealed that while all samples maintained stable resistance in ambient conditions, only the OSP-treated electrodes sustained performance under harsh environments, remaining stable for over 120 h. These findings suggest that the integration of UV-curable PVP-coated Cu paste with IPL sintering offers a cost-effective and efficient approach to fabricating durable conductive patterns on heat-sensitive substrates, particularly when combined with OSP treatment for enhanced durability in challenging environments.