Journal of Coatings Technology and Research最新文献

Reverse osmosis (RO) membranes have been widely used in seawater desalination and drinking water preparation due to their outstanding ability to retain low valence salt ions and large organic molecules. Small neutral molecules (SNMs) are widely present in water, typically represented by boric acid in seawater and urea in wastewater. Reducing SNMs to meet drinking water standards is a new challenge for RO membranes. In this study, we developed a thin-film composite RO membrane tailored for seawater desalination, demonstrating exceptional selectivity against SNMs and heightened permeability. Specifically, a nonionic surfactant, flexible polyisobutylene succinimide (PIBSI), was added into the organic phase to react with trimesoyl chloride (TMC). The results showed that the new product, PIBSI–TMC, effectively exhibited the dual function of surfactant and co-monomer changed the physicochemical structure of PA formation during the interfacial polymerization process based on the detailed characterization. PIBSI integrated into the PA matrix significantly enhanced the hydrophobicity of the membrane surface and increased the specific surface area. Simultaneously, the pore size within the layer was reduced, and defects on the RO membrane surface were filled. The objectives were achieved by enhancing the size exclusion mechanisms effect, reducing SNMs diffusion rate, and ultimately improving selectivity. Experimental results demonstrated that the novel membrane achieved excellent desalination performance and a maximum boron removal efficiency of up to 90.40% in simulated seawater (32000 ppm NaCl, 5 ppm boron) compared to virgin membrane. The produced freshwater meets drinking water standards in various regions. Additionally, it exhibited higher flux (48.0 L m⁻² h⁻¹, 55.0 bar, approximately 26.4% permeate flux decline) compared to similar membranes. In addition, the rejection of SNMs in wastewater represented by urea was also effective. Therefore, it is favorable for application in resource recovery and pollutant removal. In conclusion, this novel RO membrane holds broad prospects for applications in seawater desalination and potable water production.

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Monoclinic bismuth vanadate (BiVO₄) as an environmentally friendly bright yellow pigment has received increasing attention over the past two decades. Unfortunately, poor thermal stability and acid resistance hinder its large-scale application in the industrial field. Herein, multicoated BiVO₄@SiO₂ yellow pigments with enhanced thermal stability and acid resistance were successfully synthesized by the hydrolysis method. The effects of process parameters such as Si/Bi molar ratio (n_Si/Bi), water bath temperature (T_b), and dropwise addition rate of water (V_d) on the preparation of BiVO₄@SiO₂ yellow pigments were systematically studied. The temperature stability of once-coated BiVO₄@SiO₂ encapsulation pigments prepared under optimized conditions can be increased from 620 to 860°C. To further improve its thermal stability and acid resistance, the BiVO₄ pigments were wrapped multiple times and its temperature and acid resistance were evaluated. The results showed that after three times wrapping, the obtained BiVO₄@SiO₂ showed optimal thermal stability and could maintain yellow color at 1200°C. The high-temperature stability and antiacid corrosion highlight the promise of its potential for commercial yellow pigments.

In this study, we present a method to enhance the hydrophobic properties of organofluorosilicon styrene–acrylate emulsions while simultaneously reducing their environmental pollutional, and assess their potential for applications in oil–water separation materials, waterproof coatings, and related fields. We achieved this by developing organofluorosilicon styrene–acrylate emulsions with core–shell interpenetration properties through a meticulously designed preemulsified semicontinuous seed emulsion polymerization process. In addition, we have added sodium lignosulfonate, a green and renewable material, to the polymerization process to further enhance the environmental sustainability of these emulsions. A comprehensive characterization of the lignin-modified emulsions was conducted using various techniques, including assessments of storage stability, centrifugal stability, ionic stability, water contact angle, thermogravimetric analysis, Fourier transform infrared spectroscopy, as well as scanning and transmission electron microscopy analyses. The findings revealed that the lignin-modified emulsions exhibited similar stability to conventional phenylpropylene emulsions in terms of Ca²⁺, mechanical, and storage stability, while demonstrating notably enhanced thermal stability and hydrophobicity. Significantly, immersion of filter paper in the modified emulsion resulted in filter paper with markedly improved hydrophobic properties, while retaining surface pores and preserving filter capacity. This underscores the potential of lignin-modified emulsions for application in oil–water separation materials. Furthermore, this innovation led to a noteworthy 50% reduction in the usage of organofluorosilicone monomers, thereby mitigating potential hazards and environmental pollution associated with their use. Our utilization of sodium lignosulfonate as a modifier for organofluorosilicon styrene–acrylate emulsions represents a novel and promising approach for applications in oil–water separation and waterproof coatings. The integration of green and sustainable materials has significantly advanced environmentally friendly solutions, fostering more eco-conscious practices in industrial and commercial applications.

In this study, rosin polyethylene glycol ester was prepared by the reaction of natural rosin with PEG-400. It was modified with acrylic acid to prepare water-based ink binders. The results show that the reaction is carried out for 3 h at a molar ratio of rosin to PEG-400 of 1:4 and a catalyst and filler (Al₂O₃) of 30 wt%/RO. Products with high fixed content (83.4 wt%), low acid value (27.0 mg NaOH/g), high esterification rate (83.0%), good printability, and fast drying and flow rates are obtained. The key steps of the study include preparing polymers using natural rosin and PEG-400, esterification reaction, and modifying rosin polyethylene glycol ester emulsions. The focus of the study is to analyze the effect of the molar ratio of rosin to PEG-400, the type and content of the catalyst (filler), and the reaction time on the product to obtain the optimum process conditions. This study proposes a new method for the production of environmentally friendly water-based inks and provides valuable insights into future ink production and environmental technology.

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.

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