Journal of Coatings Technology and Research最新文献

The frequent occurrence of oil spills in recent years has led to serious contamination of water resources, and materials with superhydrophobic surface properties have attracted much attention for crude oil recovery and water contamination remediation. However, the fragile robustness of superhydrophobic materials greatly hinders their practical applications. Herein, we prepared the robust, photocatalytic superhydrophobic material of SH-ZnO-PDMS@fabric by a simple two-step immersion method. Zinc oxide nanoparticles (ZnO NPs) provided the rough surface structure, and fluorine-free dodecyltrimethoxysilane (DTMS) provided the low surface energy. Polydimethylsiloxane (PDMS) was introduced as a binder to strengthen the force between the nanoparticles and the fabric. The cotton fabric showed excellent superhydrophobicity with a water contact angle (WCA) range of 146.9–156.6°. The methylene blue (MB) in water was basically degraded after 12 h of exposure to UV lamp, manifesting that the cotton fabric had excellent photocatalytic property. The cotton fabric also showed excellent self-cleaning and antifouling properties. Importantly, SH-ZnO-PDMS@fabric maintained superhydrophobic properties after mechanical abrasion, ultrasonic washing, UV irradiation, and acid/alkali immersion. The prepared superhydrophobic materials can be repeatedly used to separate various oil–water mixtures due to their superhydrophobic and recyclable properties. This versatile, efficient, and simple strategy has good application prospects in water pollution remediation and oily wastewater treatment.

The vertical axis turbine used in the maritime energy sector must rotate and deal with turbulent flows in order to generate electricity. Structural failures and operational problems like corrosion can occur and lower turbine efficiency. Thus, additional surface protection through coatings is required for metal corrosion prevention. In these studies, the effects of turbulent flow on polyamine epoxy and fluoropolymer marine coatings were examined using electrochemical impedance spectroscopy (EIS). To simulate the flow effect, a rotating cylinder electrode (RCE) sample was placed in an aqueous solution containing 3.5 wt% sodium chloride, along with additional treatments of neutral salt spray to speed up the aging process. The fluoropolymer coating exhibits the best coating properties and provides robust corrosion protection with an impedance value of 8.7 Ω·cm². However, the results also show that turbulent flow, at a maximum speed of 5400 rpm, has an impact on coating corrosion resistance and reduces the protective properties of coatings of polyamine epoxy by up to 19% and fluoropolymer by up to 33%.

The exceptional oil–water selectivity and low oil adhesion of hydrogel materials have garnered considerable attention within the realm of oil–water separation. In this paper, semi-interpenetrating polymer networks (semi-IPN) were introduced into polyvinyl alcohol (PVA)/polyacrylamide (PAM) hydrogels, which improved the mechanical properties of the hydrogels due to the presence of physical and chemical crosslinking. The incorporation of SiO₂ nanoparticles into the hydrogel improved the surface energy and roughness, which resulted in superhydrophilic and underwater superoleophobic properties of PVA/PAM/SiO₂ semi-IPN hydrogel-coated stainless-steel mesh (SSM). The SSM coated with hydrogel demonstrated excellent resistance to underwater oil, as evidenced by a contact angle of 156°. The oil–water separation flux was as great as 1.2 × 10⁴ L m⁻² h⁻¹, and the separation efficiency exceeded 98%. Furthermore, PVA/PAM/SiO₂ semi-IPN hydrogel-coated SSM is one of the best materials for solving oil–water separation issues due to its recyclability, self-cleaning properties, and stability under acidic and alkaline conditions.

Structural colorization as a new green coloring method has received more and more attention. However, structural colors with only color can no longer meet the actual needs. It is of great practical significance to develop functional structural colors with brilliant colors and special function. In this study, Cu₂O single crystal spheres with different sizes were successfully prepared and were sprayed on the surface of polyester/cotton fabric to obtain bright purple, purple red, light blue, dark green, grass green, and orange–yellow structural colors. Due to the introduction of polyacrylate (PA) adhesive, Cu₂O structural colorized fabrics had excellent abrasion and washing colorfastness and stability. Meanwhile, the Cu₂O structural color has little influence on the original softness and air permeability of fabric. The structural colorized fabric showed excellent antibacterial properties against E. coli and S. aureus, and the antibacterial rates decreased with the increasing of particle sizes of Cu₂O spheres. The large-scale preparation of uniform structural colors on fabric can be realized by the spraying method. The fine and complex structural color patterns can also be obtained by spraying Cu₂O single crystal spheres, showing good industrial application prospects. Therefore, this study provides experimental basis for the development of functional structural colors with brilliant colors and excellent antibacterial properties.

Graphical abstract

Nowadays, geopolymer coatings have been studied a lot due to their green and sustainable properties, and they have a great potential to partially replace traditional coatings in terms of corrosion resistance and economy. In this study, metakaolin-based geopolymer coating was used as the control group, and anticorrosive coatings were prepared by adding different dosages (2–8 wt%) of ZnO fillers to study the effect of ZnO on physical properties and anticorrosion properties of metakaolin-based geopolymer anticorrosive coatings. The results showed that when the mass fraction of the zinc oxide was 8%, it had the optimum effect on physical performance. The water absorption was 12.4%, and the toughness was 3 mm. In addition, the anticorrosive properties of the coating were studied by sodium chloride (NaCl) solution immersion test, wet–dry cyclic test, salt spray test, and electrochemical test. In sodium chloride (NaCl) solution immersion, wet–dry cycle, and salt spray test, a reduction of 43.8%, 50.6%, and 74.2% in corrosion area ratio, respectively, were achieved with a coating of 8% ZnO filled as compared with pure geopolymer coatings. The results indicated that the addition of ZnO enhanced the anticorrosion performance of the coating. The macroscopic test results were verified by SEM. This study lays a foundation for the subsequent research and performance improvement of metakaolin-based geopolymer anticorrosive coatings.

Over the last decade, superhydrophobic surfaces with their new functional and structural properties have attracted a lot of interest both in the scientific research environment and in the industrial environment because of their potential to be applied in several fields, including anticorrosion, water/oil separation, ice repellency, and above all self-cleaning. This review, which should be of interest to students, researchers, and also industries focused on the chemistry of coatings, has been made with the aim of citing, explaining, and comparing in detail the structural and functional properties, the formulation techniques, the advantages, and the inconveniences of the majority of materials most used until now, and on the other hand to meet all our needs to facilitate the choice of materials for the preparation of superhydrophobic coatings according to the desired properties. This review provides a detailed analysis of recent advances in the preparation of superhydrophobic surfaces using polymeric coatings. In a significant way, the theoretical principles for the manufacturing of this type of surface have been explained, and the factors impacting the surface superhydrophobicity have been proposed. Also, an in-depth examination of the preparation approaches is categorized according to types of polymers such as polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), polystyrene (PS), polyvinylidene fluoride (PVDF), polyurethane (PU), epoxy, and other polymers. Finally, the applications and challenges related to the applicability of this type of coating in everyday life are highlighted.

The application of mesoporous silica nanoparticles (MSN) as smart containers to distribute corrosion inhibitors gradually over time for metal protection has been well documented. This material possesses unique properties such as tunable surface and pore, high thermal and chemical stability, large pore volume and pore size, relatively low toxicity, and water solubility. These properties of MSN enable it to encapsulate large volumes of corrosion inhibitors which upon installation of an appropriate gatekeeper can release inhibitors at a controlled rate thereby improving the service life of coatings when dispersed within. In this mini-review, we look at the structure and properties of MSN, various synthetic routes reported in the literature, the nucleation and growth mechanism proposed thus far, some of the challenges still encountered in the synthesis of MSN as well as various ways it has been applied as a “smart” container for the controlled release of corrosion inhibitors in coatings.

Sol–gel based coatings are used to protect metals from corrosion. They offer a barrier to the electrolyte penetration, but they do not provide active corrosion protection. Therefore, corrosion inhibitors are often added to sol–gel formulations to improve the overall corrosion behavior. Sol–gel-based coatings typically require relatively high temperatures to be properly cured, which supposes high energy consumptions and might damage some of the precursors of the formulation, including corrosion inhibitors incorporated to improve the coating’s properties. In this study, the effect of diethylenetriamine (DETA) as a curing agent, and yttrium 4-hydroxy cinnamate [Y-(4OHCin)₃] as corrosion inhibitor, on the chemistry and corrosion performance of a hybrid silica-epoxy formulation are investigated. Solid nuclear magnetic resonance and attenuated total reflectance Fourier transform infrared spectroscopy are carried out to analyze the influence of the curing agent and the corrosion inhibitor on the chemical structure of the coating. The corrosion performance is assessed by means of electrochemical impedance spectroscopy, and the results are evaluated considering the chemical study and the interaction between the different compounds.

This study aims to create paper packaging by developing paper coated with silver-exchanged zeolite that provides the necessary antibacterial properties. Various coating solutions containing different concentrations of silver-exchanged zeolite (0.1%, 0.2%, 0.3%, and 0.4%) by weight of starch mixed with starch were prepared. The study investigated the effects and properties of these silver-coated papers. Examination of the microscopic structure of the surface coated paper revealed that the coating solution effectively filled the pores of the paper, resulting in a smoother surface with even distribution of silver-exchanged zeolite. The basis weight and thickness of the coated paper increased after the coating process. The paper coated with silver-exchanged zeolite demonstrated the ability to inhibit the growth of both Gram-negative bacteria (Staphylococcus aureus) and Gram-positive bacteria (Escherichia coli). Notably, the paper coated with 0.1% silver-exchanged zeolite exhibited improved mechanical properties and a higher water contact angle compared to uncoated paper (61°–88°). This suggests that paper coated with silver-exchanged zeolite has the potential to be used as antibacterial paper for packaging food products.

In this study, we utilized nanocomposites prepared from nanosilica (SiO₂) and various polythiophene derivatives as enhancement additives for acrylic coatings. The nanocomposites were synthesized in a nitrogen environment using FeCl₃ as a catalyst in a chloroform solvent. The weight ratio of nanosilica to monomers was 2/1, specifically for the compounds (5-benzo[d]thiazol-2-yl)-7-methoxy-2-(thiophen-3-yl)benzo[d]oxazole (P1), 3-(2-benzothiazolyl)thiophene (P2), and 5-(benzo[d]thiazol-2-yl)-2-(thiophene-3-yl)benzo[d]oxazole (P3). Analysis techniques including IR, TGA, SEM, and UV–Vis were employed to demonstrate the formation of polythiophenes on the surface of the nanosilica. The presence of polythiophenes on the nanosilica broadened the UV absorption region. Upon adding the nanocomposites to acrylic coatings, the UV absorption intensity of the coatings was increased. Notably, the coating containing SiO₂-P3 nanocomposite exhibited the highest abrasion resistance among all the investigated samples. By varying the content of SiO₂-P3 nanocomposite, we observed enhanced abrasion resistance, adhesion, pencil hardness, and gloss of the acrylic coating. The maximum values were achieved when the content of SiO₂-P3 nanoparticles was 2 wt.%. The SiO₂-P3 nanoparticles were uniformly dispersed in the acrylic coatings, leading to an improvement in the coating's sunlight-reflective ability. Consequently, the acrylic/SiO₂-P3 nanocomposite coatings exhibited potential for outdoor applications, particularly as UV-resistant coatings.