Progress in Organic Coatings最新文献

It is crucial to enhance the concrete permeation resistance to liquefied natural gas (LNG) by utilizing a functional coating having excellent cryogenic stability. In this study, a novel method was provided to prepare a modified nanosilica-resin composite coating with excellent oleophobicity and permeation resistance to small molecule alkane oils. The properties of this coating were comprehensively characterized in terms of wettability test, mechanical stability test, chemical stability test, and oil impermeability test. Additionally, its cryogenic stability was also evaluated through the above methodologies. The results showed that the contact angle of mineral oil on the coating exceeds 150°, with a contact angle loss rate of only 2.98 % after 100 cycles of sandpaper abrasion. The contact angle remained above 130° after 24-h immersion in HCl, NaOH, and NaCl solutions, indicating its excellent chemical stability. Upon application, the coating significantly reduces the oil absorption rate of concrete exposed to small-molecule alkane oil by >80 %. More significantly, the contact angle of the coating remained above 150° even after cryogenic treatment, exhibiting a minimal contact angle loss rate of just 2.77 % following 100 cycles of sandpaper abrasion, demonstrating excellent cryogenic stability. The scanning electron microscope and X-ray photoelectron spectrometer results showed that the coating can maintain micro-nano rough structure and chemical structure of fluorine-containing low surface energy functional groups after cryogenic treatment, attributing to its remarkable stability. These findings underscore the novel coating's substantial potential for application potential in various cryogenic industrial fields.

Addressing the significant challenges stemming from human activity on the environment requires active participation from all sectors, including the coatings industry. While there has been considerable effort to encourage individual involvement and responsibility, there lacks an overarching eco-strategy for the industry as a whole. This work proposes a guideline to prioritize efforts for maximum positive environmental impact, focusing specifically on the direct product-related impacts of the coatings industry (Scope 3).

The eco-strategy is founded on two main components: a “red list” outlining hazardous ingredients to be avoided to comply with legislation and a Life Cycle assessment of all raw materials used in the coatings industry in a year.

It concludes that a “red list” will be different when the coatings are for industrial use under controlled conditions or if the coatings are for consumer use. Hazardous ingredients may be required to enable production of durable coatings to be used in industry, while the same hazardous substances are recommended to be reduced or even phased out in consumer products.

The findings from the Life Cycle Assessment (LCA) on the industry's use of raw materials reveals that epoxy resins, titanium dioxide, acrylic resins, and metallic zinc dust collectively account for over 50 % of environmental impacts across all assessed categories due to their high usage volumes combined with their impact potential. As such, substitution or further development of these raw material groups should be prioritized for future research and development in academic and within the industry.

Moreover, the eco-strategy underscores the importance of durability in achieving environmental sustainability. Any substitution of raw materials must ensure comparable or even improved durability of the coatings to maintain environmental benefits.

Due to the increased presence of hydrophilic groups in waterborne polyurethane (WPU) coatings, consequently leading to compromised corrosion resistance and reduced service life. To solve the problem, a series of waterborne polyurethanes were synthesized via internal emulsification using dicyclohexylmethane diisocyanate (HMDI) and polytetrahydrofuran ether diol (PTMG) as the primary raw materials. The triethanolamine (TEOA) was used as a crosslinking agent and corrosion inhibitor, while N- (β-aminoethyl) -γ-aminopropyl trimethyl-(ethyl) oxy-silane (KH-792) was introduced as a coupling agent to establish a system with a dual crosslinking structure. The crosslinking degree of the double network structure can be adjusted by changing the amount of KH-792. Then the influence of KH-792 content on the performance of SWPU dispersions and film were studied. The research shows that the waterborne polyurethane with a KH-792 content of 3 wt% exhibits exceptional mechanical strength, reaching 34.64 MPa, with only 3.32 % water absorption and an adhesion strength of 2.64 MPa. Furthermore, it exhibited a high impedance modulus (2976.4 Ω/cm²) at low frequencies. Therefore, this compound holds promising potential for application in anti-corrosion coatings field.

Redispersible powder coatings (RPCs), which do not rely on water in storage cans, provide a sustainable route to lightweight transportation and biocide-free storage of architectural coatings. However, difficulties with powder production and subsequent film formation and particle dispersion upon water addition, have prevented the method from becoming a reliable alternative to traditional waterborne coatings.

This study investigates optimization of a spray drying process for vinyl acetate-ethylene (VAE) polymer dispersions, as well as the mechanisms underlying film formation of redispersible polymer powders (RPPs) in water.

Spray drying of VAE dispersions was carried out in the presence of a protective colloid and, when necessary, the inclusion of anticaking agents. The addition of protective colloid and anticaking agents, as well as reduction of the inlet temperature, reduced the particle size and increased the spray drying yield. With a finer particle size of the anticaking agents, free-flowing powders were obtained. For evaluation of the effects on the spray drying process and the resultant powder characteristics, VAE dispersions with four different polymer glass transition temperatures (T_g) and two alternative particle stabilizations, polyvinyl alcohol (PVA) and an emulsifier-PVA mixture, were used. For PVA-stabilized VAE (P-VAE) dispersions, particle sizes down to 1.0 μm and process yields around 80 wt% were achieved, while the lowest particle size and highest yield achievable was 4.69 μm and 29.2 wt%, respectively, for emulsifier- and PVA-stabilized VAE (EP-VAE) dispersions. The morphology of the prepared powders was affected by the choice of stabilization type. When using P-VAE dispersions, particles agglomerated, forming a raspberry like structure, whereas EP-VAE particles resulted in larger, spherical particles.

When prepared powder polymers were used to formulate coatings, the wet scrub resistance (WSR) was influenced by the choice of VAE polymer with varying T_g and stabilization mechanism of the polymer dispersions. Coatings formulated with a low T_g EP-VAE exhibited enhanced film formation, leading to a higher WSR, while high T_g EP-VAE resulted in a lower WSR. Conversely, P-VAE powders did not provide coherent coating films and washed away completely after 200 cycles in the WSR test, however, provided favorable results with the addition of a solid plasticizer.

Nowadays, multifunctional superhydrophobic coating has drawn widespread attention by virtue of its great water-repellent property, whereas the fragile mechanical and chemical durability of superhydrophobic coating greatly limits its practical application. Herein, a robust and multifunctional superhydrophobic composite coating (CFRE-SP@Fe₃O₄) with anti-corrosion, delay-icing and self-deicing performance is constructed via simple imprinting-demolding process on the carbon fiber reinforced epoxy resin (CFRE) surface and post-deposition modification with polydimethylsiloxane (PDMS) and epoxy resin modified Fe₃O₄ nanoparticles. The obtained CFRE-SP@Fe₃O₄ coating displays a superhydrophobic property with a WCA of 155° ± 1.2°. By virtue of the protection effect of the robust micro-grid structures for the inner superhydrophobic Fe₃O₄ nanoparticles (SP@Fe₃O₄), the CFRE-SP@Fe₃O₄ coating still maintains great superhydrophobicity after linear friction for 100 times. Additionally, compared with the carbon steel treated with CFRE, the impedance modulus at lowest frequency of CFRE-SP@Fe₃O₄ coating treated group further increase with a value of 10⁷ Ω·cm², confirming the excellent anti-corrosion performance. Owing to the air pocket captured by the micro-/nanostructure on the superhydrophobic surface, the icing time of the CFRE-SP@Fe₃O₄ surfaces extends from 60 s to 2130 s. Moreover, combined with the photothermal conversion performance of carbon fiber and Fe₃O₄ nanoparticles, the ice on the CFRE and CFRE-SP@Fe₃O₄ coatings surfaces begin to melt 137 s, displaying the excellent self-deicing performance.

Passive daytime radiative cooling technology is a highly efficient cooling technology with zero energy consumption. When utilized for personal thermal management, radiative cooling textiles are capable of finely regulating the temperature of the human skin microenvironment. This study presents a cellulose acetate (CA) hierarchical porous coated textile that accomplishes high reflectance of sunlight over the full wavelength range, with a low cost and scalability, and a simple preparation procedure. With a high reflectance of 0.91 in the solar wavelength band and a high emissivity of 0.95 in the atmospheric window wavelength band, the CA hierarchical porous coated textile offers exceptional spectrally selective performances. It manifests a subambient cooling temperature of up to 19.0 °C and a skin overheating prevention effect of up to 4.2 °C. Furthermore, the coated textile possesses promising abrasion resistance, acid-alkali corrosion resistance, and mechanical properties. The present work provides a facile path for the development of green-based radiative cooling coated textiles.

Urinary catheters necessitate a surface with antifouling and lubricating properties in order to mitigate bacterial infection, calculus formation, and tissue trauma. Hydrophilic coating is a promising strategy but suffers from the complications of the manufacturing method as well as the lack of longevity. Herein, we report an antifouling and lubricating hydrophilic coating based on zwitterionic copolymer poly(2-Methacryloyloxyethyl phosphatidylcholine-co-hydroxyethyl methacrylate-co-(Benzoyl)phenyl methacrylate (poly(MPC-co-HEMA-co-BP)) through pre-gel solution spin-coating followed by UV-curing. The poly(MPC-co-HEMA-co-BP (PMHB) coatings possess hygroscopic properties that facilitate the formation of a hydrated layer, thereby leading to friction reduction. Moreover, both antibacterial and protein resistance tests substantiate the exceptional antifouling characteristics exhibited by the PMHB coating. Furthermore, after 7 days of coincubation, the antibacterial rates of PMHB coatings against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Proteus mirabilis (P. mirabilis) are 72.98 %, 75.11 %, and 88.23 %, respectively. Subsequently, PMHB coating reduced the attachment of encrustation in a 7 days artificial urine cycling experiment. This study brings new perspective on designing urinary catheter surfaces with lubricating and antifouling properties.

The demand for textiles with functional properties has been increasing over the past few decades, driven by both civilian and military applications. In this study, we present a method to impart flame retardant (FR) and insect repellent (IR) properties to nylon-cotton blends. Flame retardancy was achieved by covalently attaching phytic acid, a bio-derived material, to the hydroxyl groups of cotton in nyco fabrics. Subsequently, these FR-treated nyco fabrics were coated with an acylate-based monomer along with permethrin to confer insect-repellent properties. FTIR-ATR spectroscopy confirmed the presence of weight of phytic acid on nyco fabric and the weight gain from this was 6 % with respect to initial fabric weight. The multifunctional fabrics exhibited a 200 % increase in char formation upon thermal degradation compared to untreated nyco. Moreover, the multifunctional fabrics demonstrated self-extinguishing properties with a char length of <15 cm, whereas untreated fabrics burned completely. In cone calorimeter experiments, FR-treated fabrics showed a reduction of over 25 % in total heat release compared to untreated controls. The addition of FR facilitates char formation and the release of non-flammable gases such as water vapor (H₂O), carbon dioxide (CO₂), and ammonia (NH₃), suggesting a condensed phase mechanism of FR action as evident from TGA-FTIR evolved gas analysis. The insect repellent properties (IR) were evaluated using a tube test method as described by the World Health Organization, revealing a knockdown rate exceeding 98 % for fabrics treated with insect repellent.

Marine equipment power systems often operate under high-temperature conditions, and metal component corrosion in high-temperature environment can lead to failure of the entire system, substantial economic losses and environmental problems. High-temperature coatings can protect metals against corrosion through thermal insulation and shielding. However, compared with a normal temperature, a high-temperature marine environment significantly exacerbates coating damage and metal corrosion. The abundance of certain chemical factors, such as the presence of chloride ions, metal ions, and undissociated organic acids and acidic pH levels, and certain biological factors, such as corrosive microorganisms and toxic substances derived from the substrate pose serious challenges for high-temperature coatings and metal protection measures. Moreover, the type of coating, preparation process and type of substrate are closely related to metal corrosion in high-temperature environments. In this review, these potential corrosion enhancement factors and corrosion mechanisms are introduced, and engineering perspectives on the control of high-temperature metal corrosion (HTMC) are provided.

Fly ash (FA), a hazardous byproduct of coal combustion in power plants, poses significant environmental and health risks due to improper disposal and utilization. This study introduces a facile, sustainable, and cost-effective method for converting FA into a robust superhydrophobic material for various substrates. -FA particles are modified with polydopamine (PD) in water and covalently grafted with octadecylamine (ODA) via the Michael Addition-Schiff Base reactions, resulting in robust superhydrophobic FA (SH-FA) with a water contact angle (WCA) of 163° (±3.1). When applied as a coating to jute, cotton, polyester fibers, PU sponge, and wood, they became superhydrophobic, with WCAs ranging from 154.7 to 161.2° except for the wood substrate, which achieved a WCA of 132° (±3°). The coated polyester fabric exhibited remarkable durability, retaining consistent WCA values after 70 abrasion cycles, 75 adhesive tape peelings, and 20 detergent washing cycles. It also showcased excellent self-cleaning properties, effectively repelling dust and various liquids. Additionally, the coated PU sponge demonstrated exceptional performance in separating oil from different oil/water mixtures, achieving rapid separation of organic solvents within seconds and maintaining a separation efficiency of over 98% even after 12 reuse cycles. These results indicate the potential for transforming FA through effective management.