Polymer Coatings Research Articles

Selective and stable CO2 electroreduction at high rates via control of local H2O/CO2 ratio

Controlling the concentrations of H2O and CO2 at the reaction interface is crucial for achieving efficient electrochemical CO2 reduction. However, precise control of these variables during catalysis remains challenging, and the underlying mechanisms are not fully understood. Herein, guided by a multi-physics model, we demonstrate that tuning the local H2O/CO2 concentrations is achievable by thin polymer coatings on the catalyst surface. Beyond the often-explored hydrophobicity, polymer properties of gas permeability and water-uptake ability are even more critical for this purpose. With these insights, we achieve CO2 reduction on copper with Faradaic efficiency exceeding 87% towards multi-carbon products at a high current density of −2 A cm−2. Encouraging cathodic energy efficiency (>50%) is also observed at this high current density due to the substantially reduced cathodic potential. Additionally, we demonstrate stable CO2 reduction for over 150 h at practically relevant current densities owning to the robust reaction interface. Moreover, this strategy has been extended to membrane electrode assemblies and other catalysts for CO2 reduction. Our findings underscore the significance of fine-tuning the local H2O/CO2 balance for future CO2 reduction applications.

Новітні технології в екологічно безпечних полімерних покриттях: дослідження, технології, перспективи

The scientific work is aimed at the study of environmentally friendly polymer coatings in the automotive industry, which constantly attracts the attention of scientists and practitioners. The article analyzes the current state of technology in this area, reviews the latest research and technological developments, and discusses their prospects for implementation in production. Starting with a review of the latest research on paints and coatings, the paper goes on to discuss self-healing materials and microcapsules that have the potential to create resistant and durable coatings.The paper also discusses anti-corrosion coatings, which are an important part of protecting automotive structures from the effects of negative environmental factors. Particular attention is paid to the development of environmentally friendly polymer coatings that meet the requirements of sustainable development and reduce the environmental impact of the industry on the environment.In addition, the latest trends in the industry are analyzed, which allows us to predict further directions of technology development and implementation of innovative solutions. The work has important practical application in the automotive industry, contributing to improving the quality of automotive coatings protection against corrosion and extending their service life in various operating conditions. The work is aimed at highlighting relevant aspects of research in the field of environmentally friendly polymer coatings and provides a valuable contribution to the development of this important industry. The results will improve the quality and duration of corrosion protection of paintwork, metal structures and other products.The use of the latest materials and technologies in the manufacture of coatings is driven by the need for their environmental friendliness, efficiency and durability. However, the introduction of some new technologies faces limitations, in particular, related to their economic feasibility and scalability. In this regard, further research is needed to optimize technologies and materials to achieve greater efficiency in road transport.

Antifouling Properties of Electrospun Polymeric Coatings Induced by Controlled Surface Morphology

Nosocomial infections affect implanted medical devices and greatly challenge their functional outcomes, becoming sometimes life threatening for the patients. Therefore, aggressive antibiotic therapies are administered, which often require the use of last‐resort drugs, if the infection is caused by multi‐drug‐resistant bacteria. Reducing the risk of bacterial contamination of medical devices in the hospitals has thus become an emerging issue. Promising routes to control these infections are based on materials provided with intrinsic bactericidal properties (i.e., chemical action) and on the design of surface coatings able to limit bacteria adhesion and fouling phenomena (i.e., physical action), thus preventing bacterial biofilm formation. Here, we report the development and validation of coatings made of layer‐by‐layer deposition of electrospun poly(vinylidene fluoride‐co‐trifluoro ethylene) P(VDF‐TrFE) fibers with controlled orientations, which ultimately gave rise to antifouling surfaces. The obtained 10‐layer surface morphology with 90° orientation fibers was able to efficiently prevent the adhesion of bacteria, by establishing a superhydrophobic‐like behavior compatible with the Cassie‐Baxter regimen. Moreover, the results highlighted that surface wettability and bacteria adhesion could be controlled using fibers with diameter comparable to bacteria size (i.e., achievable via electrospinning process), by tuning the intra‐fiber spacing, with relevant implications in the future design of biomedical surface coatings.

Nanomaterials as Next-Gen Corrosion Inhibitors: A Comprehensive Review for Ceramic Wastewater Treatment

This study reviews the use of corrosion inhibitors in industrial wastewater treatment, specifically in ceramic wastewater. It discusses the main problem limits the use of treated wastewater, which is corrosion behavior. To reduce this behavior and enable safe reuse of industrial wastewater, corrosion inhibitors are used. The study aims to provide insights into the selection, use, and effectiveness of corrosion inhibitor types in the media under study. The results can help engineers, researchers, and wastewater treatment professionals to find the best corrosion inhibitors for various municipal wastewater applications, increasing the sustainability and efficiency of wastewater treatment processes. The ceramic industry faces challenges in managing complex aqueous effluents generated from mining, shaping, glazing, and manufacturing processes. Nanomaterial-based alternatives, such as titanium nanotubes, zinc oxide nanoparticles, nanoenhanced filters, and stimuli responsive polymer and silica coatings, have emerged as promising next-generation corrosion inhibitors due to their multilayer passivation and high specific surface area. The analysis focuses on the feasibility of these materials' mechanisms, such as crystal deformation, nucleation hindrance, coating barriers, and passivation improvement, in industrial settings. In conclusion, the use of corrosion inhibitors in industrial wastewater treatment can significantly improve the sustainability and efficiency of wastewater treatment processes. Understanding the mechanisms by which these nanomaterials influence crystal growth modification, deposition kinetics, and passivation performance could lead to more effective and sustainable solutions for industrial wastewater treatment.

Anticorrosion Performance of Waterborne Coatings with Modified Nanoscale Titania under Subtropical Maritime Climate.

Steel structures located in subtropical marine climates face harsh conditions such as strong sunlight and heavy rain, and they are extremely corroded. In this study, a waterborne coating with excellent corrosion resistance, hydrophobic ability, high-temperature resistance and high density was successfully prepared by using modified nanoscale titania powders and grafted polymers. The effects of three modifiers on titania nanoparticles and waterborne coatings' properties were studied independently. The experimental results showed that the activation index of the modification employing methacryloxy silane reached 97.5%, which achieved the best modification effect at 64.4 °C for 43.3 min. The waterborne coating with nanoscale titania modified by methacryloxy silane exhibited the best hydrophobic effect, with a drop contact angle of 115.4° and excellent heat resistance of up to 317.2 °C. The application of the waterborne modified coating in steel structures under subtropical maritime climates showed that the waterborne titania coatings demonstrated excellent resistance to corrosion, high temperatures and harsh sunlight, with a maximum service life of up to five years. Economic analysis indicated that, considering a conservative three-year effective lifespan, this coating could save more than 50% in cost compared with conventional industrial coatings. Finally, the strengthening mechanism of the polymer coatings with modified nanoscale titania was analyzed.

Effect of ZrO2 nanoparticles on the self-lubrication behavior of the linseed oil-loaded microcapsule/ epoxy composite coatings

Smart polymeric coatings play a crucial role in protecting steel surfaces from corrosion and wear. One of progressive smart behavior is self-healing behavior especially in self-healing epoxy coatings. Creating or improving the second smart behavior is known as a new trend for these smart materials. This study aims to investigate the effects of ZrO2 nanoparticles on the self-lubricating behavior as the second smart behavior of the linseed oil-loaded microcapsule/epoxy composite coatings. To do so, the in-situ polymerization method was used for the synthesis of linseed oil-loaded microcapsule. Results showed that the average size of prepared linseed oil-loaded microcapsules was 563 nm. The composite coatings were prepared by different content of ZrO2 nanoparticles (0, 3, 6, 9, 12, and 15 wt%) and constant content of linseed oil-loaded microcapsules (5 wt%). The tribological performance of samples was studied using pin-on-disk test. The worn surface of the samples was also studied using field emission scanning electron microscope (FESEM) images. Results proved that the frictional coefficient and wear rate of the samples were significantly decreased by increasing the concentrations of the ZrO2 nanoparticles up to 9 wt%. The lowest friction coefficient and wear rate values of 0.085 and 0.142 × 10−6 mm3/Nm were obtained for 5 wt% linseed oil-loaded microcapsules/epoxy with 9 wt% ZrO2 which were about 82 % and 88 % lower than those of pure epoxy coating.

Cellular Uptake of Upconversion Nanoparticles Based on Surface Polymer Coatings and Protein Corona.

Upconversion nanoparticles (UCNPs) are materials that provide unique advantages for biomedical applications. There are constantly emerging customized UCNPs with varying compositions, coatings, and upconversion mechanisms. Cellular uptake is a key parameter for the biological application of UCNPs. Uptake experiments have yielded highly varying results, and correlating trends between cellular uptake with different types of UCNP coatings remains challenging. In this report, the impact of surface polymer coatings on the formation of protein coronas and subsequent cellular uptake of UCNPs by macrophages and cancer cells was investigated. Luminescence confocal microscopy and elemental analysis techniques were used to evaluate the different coatings for internalization within cells. Pathway inhibitors were used to unravel the specific internalization mechanisms of polymer-coated UCNPs. Coatings were chosen as the most promising for colloidal stability, conjugation chemistry, and biomedical applications. PIMA-PEG (poly(isobutylene-alt-maleic) anhydride with polyethylene glycol)-coated UCNPs were found to have low cytotoxicity, low uptake by macrophages (when compared with PEI, poly(ethylenimine)), and sufficient uptake by tumor cells for surface-loaded drug delivery applications. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) studies revealed that PIMA-coated NPs were preferentially internalized by the clathrin- and caveolar-independent pathways, with a preference for clathrin-mediated uptake at longer time points. PMAO-PEG (poly(maleic anhydride-alt-1-octadecene) with polyethylene glycol)-coated UCNPs were internalized by energy-dependent pathways, while PAA- (poly(acrylic acid)) and PEI-coated NPs were internalized by multifactorial mechanisms of internalization. The results indicate that copolymers of PIMA-PEG coatings on UCNPs were well suited for the next-generation of biomedical applications.

Study on Antibacterial Durability of Waterproof Coatings with Different Base Materials

Microbial corrosion of waterproof coatings causes structural damage to buildings and renovation materials and severely threatens human health. In practical applications, coatings with different base materials show different durabilities to external environmental influences. There is little literature on the antimicrobial durability performance of waterproof coatings. Therefore, this paper selected four standard waterproofing coatings, including polyurethane coatings, cement-based coatings, asphalt-modified polymer coatings, and polymer emulsion coatings, as the main body of this study. Their antimicrobial abilities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, Candida albicans, and mold were tested after experiencing three kinds of harsh environments: Ultraviolet ray (UV), water immersion, and low temperature. The results show that the extreme climates significantly reduced the ability of the four coatings to resist mold, and the highest growth rate of bacteria was 54.64%. Under UV conditions, the polymer emulsion coatings were significantly more resistant to Candida albicans, and the optical density of the bacterial liquid showed a negative growth trend. The microstructural integrity of the polymer emulsion coatings was found to be damaged by Scanning Electron Microscope (SEM) observation. This work improves the durability application research on these coatings and provides a valuable reference for developing new environmentally friendly, antibacterial, and anticorrosive waterproof coatings.

Initial Experience with a New Self-Expanding Open-Cell Stent System with Antithrombotic Hydrophilic Polymer Coating (pEGASUS Stent) in the Treatment of Wide-Necked Intracranial Aneurysms.

We report our initial experience with endovascular embolization of intracranial aneurysms using this new self-expanding open-cell stent system (pEGASUS stent system) with the antithrombogenic hydrophilic polymer coating. We retrospectively reviewed all patients treated with stent-assisted coiling or the Woven EndoBridge device using the pEGASUS stent system between September 2022 and June 2023. Demographic, clinical, and angiographic data were analyzed as well as short-term follow-up, including procedural complication rates and aneurysmal occlusion rates using the Raymond-Roy occlusion classification (RROC). Twelve patients with 12 wide-necked intracranial aneurysms were treated with the pEGASUS stent system, including 2 acutely ruptured aneurysms embolized in an emergency setting. The treated aneurysms were located at the anterior communicating artery (25.0%), the basilar artery (50.0%), the middle cerebral artery (16.7%), and the internal carotid artery (8.3%). All stents were deployed successfully. Immediate complete aneurysmal occlusion (RROC class I) was achieved in 83.3% (10/12) and near-complete occlusion (RROC II) in 16.7% (2/12). No periprocedural complications occurred in patients treated in the elective setting. A single case of intraoperative in-stent thrombus formation occurred during the treatment of an acutely ruptured basilar aneurysm and was resolved with intravenous Tirofiban. No other periprocedural complications occurred. Eleven out of 12 patients were available for follow up (mean 7.4 months). Complete aneurysmal occlusion without in-stent stenosis (ISS) was seen in 10 patients (90.9%). One patient (9.1%) showed aneurysmal reperfusion (RROC IIIb) with asymptomatic moderate ISS. Our initial results demonstrate that the pEGASUS stent system appears to be a safe and effective device for stent assisted embolization of wide-necked intracranial aneurysms. More data is necessary to evaluate long-term follow-up.

Insect-derived chitosan, a biopolymer for the increased shelf life of white and red grapes

Post-harvest water loss and microbial infections are the root cause of the rapid deterioration of fresh fruit after the picking process, with both environmental and economic implications. Therefore, it is crucial to find solutions that can increase the shelf life of fresh fruits. For this purpose, edible coatings, naturally derived and non-synthetic, are acknowledged as a safe strategy. Among polymeric coatings, chitosan is one of the most effective. In this work, this biopolymer, produced from chitin extracted from Hermetia illucens, an alternative and more sustainable source than crustaceans (the commercial one), was exploited to extend the shelf life of white and red grapes. Chitosan from H. illucens pupal exuviae, at 0.5 % and 1 % concentrations, was applied on both grapes, which were then stored at room temperature or 4 °C. The study of chemical-physical parameters such as weight loss, Total Soluble Solids and pH, demonstrated the effectiveness of the biopolymer, even better than crustacean chitosan. Moreover, the analysis of nutraceutical properties has demonstrated that this natural edible coating improves the quality of grapes, with beneficial effects for human health. The obtained results, therefore, confirmed the viability of using insect-chitosan as an alternative to crustaceans for the preservation of fresh food.

Современные стратегии формирования полимерных покрытий. Часть III

Современные стратегии формирования полимерных покрытий. Часть III

Tribocorrosion properties of NdCl3-modified resin-based polymeric coatings in contaminated lubricating oils

To improve the tribological performance and corrosion resistance of engine bearings exposed to contaminated lubricating oil, polymer coatings containing NdCl3 at concentrations of 3.45 wt%, 5.17 wt%, and 6.89 wt% were developed, respectively. These coatings were applied to the surfaces of copper and aluminum alloys using a liquid spraying technique, aiming to assess their corrosion and wear resistance. Electrochemical experiments showed that the coating with a 3.45 wt% NdCl3 concentration exhibited superior corrosion resistance, as evidenced by the highest self-corrosion potential and polarization resistance. Furthermore, friction tests on the corroded samples revealed that the 3.45 wt% NdCl3 coating also demonstrated the lowest coefficients of friction and wear rates. This is due to the addition of an appropriate amount of NdCl3, which densifies the internal structure of the coating and improves the mechanical properties of the coating, thereby significantly improving its corrosion and wear resistance.

Antibacterial, Antifungal, and Cytotoxic Potential of PlumbaginLoaded pH-Responsive Vaginal Nanoformulations.

Plumbagin is a naphthoquinone from the roots of the Plumbago species and exhibits anticancer activity. Translational usage of plumbagin in biomedical sciences is restricted due to its poor solubility and bioavailability. Therefore, pH-responsive plumbagin-loaded vaginal nanoformulations with polylactic acid (PLA)-chitosan polymeric coat were fabricated by inotropic gelation technique. Among the four (F1, F2, F3, F4) nanoformulations prepared, F3 exhibited good interaction of polymers with plumbagin as evidenced by FTIR, XRD, and thermal analysis. The positive zeta potential (48.4 ± 5.57mV), optimal size (694 ± 65.76nm), low PDI (0.157), and good encapsulation efficiency (77.8 ± 3.62%) of F3 were significant. The indirect method of drug loading (58.35 ± 5.00%) confirmed the drug content of about 495.44 ± 5.00µg of plumbagin in 1mg of F3. The drug loading pattern was confirmed by TEM analysis, and the spherical morphology of the nanocomposite was confirmed by SEM analysis. F3 formulation showed 46% and 25.2% of drug release in 24h in simulated vaginal fluid at pH 4.5 and 7 respectively with sustained release and hydrolyses of lactic acid from PLA. Among all the nanoformulations evaluated, nanoformulation F3 with promising physicochemical properties showed good antifungal and antibacterial activity against various fungal and bacterial strains. F3 exhibited potent cytotoxicity with an IC50 of 3.6 ± 0.12µg/ml for HeLa and an IC50 of 0.81 ± 0.01µg/ml for SiHa cells. Altogether, the nanoformulation F3 exhibited potent antimicrobial activity against vaginal infections and cytotoxicity against cervical cancer cell lines.

Effect of Polymer and Cell Membrane Coatings on Theranostic Applications of Nanoparticles: A Review.

The recent decade has witnessed a remarkable surge in the field of nanoparticles, from their synthesis, characterization, and functionalization to diverse applications. At the nanoscale, these particles exhibit distinct physicochemical properties compared to their bulk counterparts, enabling a multitude of applications spanning energy, catalysis, environmental remediation, biomedicine, and beyond. This review focuses on specific nanoparticle categories, including magnetic, gold, silver, and quantum dots (QDs), as well as hybrid variants, specifically tailored for biomedical applications. A comprehensive review and comparison of prevalent chemical, physical, and biological synthesis methods are presented. To enhance biocompatibility and colloidal stability, and facilitate surface modification and cargo/agent loading, nanoparticle surfaces are coated with different synthetic polymers and very recently, cell membrane coatings. The utilization of polymer- or cell membrane-coated nanoparticles opens a wide variety of biomedical applications such as magnetic resonance imaging (MRI), hyperthermia, photothermia, sample enrichment, bioassays, drug delivery, etc. With this review, the goal is to provide a comprehensive toolbox of insights into polymer or cell membrane-coated nanoparticles and their biomedical applications, while also addressing the challenges involved in translating such nanoparticles from laboratory benchtops to in vitro and in vivo applications. Furthermore, perspectives on future trends and developments in this rapidly evolving domain are provided.

Mathematical Analysis of Nonlinear Differential Equations in Polymer Coated Microelectrodes

A theoretical analysis is conducted on the electrochemical behaviour of micro disk electrodes coated with thin coatings of electroactive polymers. The main focus of efforts to characterize the planar diffusion chemical reaction within polymer-modified ultra-microelectrodes is the creation of a theoretical model that explicitly takes into account the potential for the polymer film to cover the inlaid micro disc support surface. Approximate formulae for the steady-state amperometric response and formulation of the boundary value problem are given. The impact of substrate concentration, mediator concentration and current responsiveness in the solution besides the polymer film is also investigated. Akbari-Ganji method (AGM) and differential transformation method (DTM), two adequate and widely available analytical methods, were utilized to determine the steady-state non-linear diffusion equation. The approximate analytical solution for the substrate concentration and mediator concentration and the current for the small experimental kinetic values and diffusion coefficients are presented. We additionally determine the problem’s numerical solution using the MATLAB tool. A satisfactory agreement can be seen when the numerical outcomes verify with the analytical findings.

RTV/GO-SiO2 anti-corrosion nanocomposite coating

Corrosion stands out as a leading factor contributing to the deterioration of industrial components, particularly in equipment utilized for oil and gas transmission and processing. Room temperature vulcanized silicone rubber (RTV) emerges as a promising solution for corrosion prevention due to its notable features including high hydrophobicity, adhesion, and thermal stability. This study focuses on enhancing anti-corrosion properties by applying coatings of RTV polymer with graphene oxide (GO) sheets (RTV-GO) or GO decorated with silicon oxide (RTV/GO-SiO2) onto X60 steel substrates. The investigation delves into the microstructure of the coating, surface hydrophobicity, adhesion to the substrate, and its efficacy in corrosion protection. Various techniques such as X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) were employed to analyze the nanocomposites. Furthermore, corrosion resistance was evaluated through open circuit potential analysis, potentiodynamic polarization, electrochemical impedance spectroscopy, and salt spray testing. Results indicate that incorporating GO and hybrid GO-SiO2 into the RTV polymer matrix not only enhances the interface strength between the coating and steel substrate but also boosts corrosion resistance by up to 10-fold compared to uncoated substrates.

Insights in emerging Ti3C2Tx MXene-enriched polymeric coatings for metallic surface protection: Advancements in microstructure, anti-aging, and electrochemical performance

This study provides new insights into the development of high-performance MXene-reinforced coatings to strengthen polymeric nanocomposites by enhancing microstructure, anti-aging properties, corrosion resistance, and robustness. MXene nanoparticles, labeled 25C and 80C, were synthesized using two different methods and incorporated at concentrations ranging from 0.1 to 2.0 wt% into epoxy composites. The results demonstrated that 80C MXene, characterized by its finer morphology and superior dispersion, significantly improved the composite's performance compared to 25C. Electrochemical Impedance Spectroscopy (EIS) tests, along with long-term exposure assessments, suggested that incorporating both types of MXene nanoparticles enhances the corrosion protection performance of epoxy coatings over time. Micro-CT analysis revealed that both types of MXene substantially reduced defects and voids in the polymeric matrix, resulting in enhanced protective performance. This void reduction confirms that the incorporation of both 25C and 80C MXene improves microstructural integrity by filling voids and creating a more continuous, uniform structure, particularly in samples with 0.1 % to 1.0 % MXene flakes. The findings also highlighted MXene's potential in modifying the anti-aging properties of epoxy by inhibiting free radical generation and enhancing the composite's resistance against corrosion. Both 25C and 80C MXene-epoxy groups exhibited a clear trend of diminishing free radical intensity with increasing MXene concentration up to 1.0 %, with free radical intensity reduced by over 40 % compared to neat epoxy. The relationship between MXene concentration and reinforcement was also investigated, revealing superior corrosion protection properties at concentrations of 0.5–1.0 wt%. This research offers a profound understanding of MXene's potential in polymer-based composites, laying a foundation for future investigations aimed at utilizing MXene to achieve superior material properties for a wide range of applications, particularly in the realm of metallic surface protection.

Silicone‐containing polyurea elastomer possessing main‐chain boron–oxygen bonds with delayed stress relaxation and improved adhesive properties

AbstractPolyurea (PU) elastomers have attracted considerable attention in the field of protective polymeric coatings. In this work, a dithiol‐terminated boronic ester was synthesized and used to incorporate dynamic boron–oxygen (B–O) bonds in the PU main chain based on thiol isocyanate while amino‐terminated polydimethylsiloxane (PDMS) was introduced to retain good chain flexibility. The modified PU elastomer was found to have a microphase‐separated structure in which the hard blocks served as physical crosslinks. The glass transition temperature (Tg) slightly increases when dynamic B–O bonds exist while further introduction of PDMS soft segment can lower Tg to −55.63 °C. The introduction of dynamic B–O bonds and diminished hydrogen bonding led to a decrease in mechanical strength and elongation at break. Interestingly, the simultaneous incorporation of PDMS and dynamic B–O bonds is favorable for strain rate dependence and suppressing stress relaxation. The potential for bond‐exchange interactions between the dynamic B–O bonds and hydroxyl groups on metal surfaces substantially improved the adhesion of the PU elastomer to metal substrates. Therefore, our work can offer valuable insights for the structural design of functional PU coatings tailored for anti‐impact applications. © 2024 Society of Chemical Industry.

Unraveling the detrimental effect of polymeric microcapsules on the corrosion performance of epoxy resin coatings

Organic micro- or nanocapsules are widely used as reservoirs to carry sealing agents or corrosion inhibitors to achieve the self-healing functionality of coatings. To understand the impact of the capsules' incorporation on the barrier properties of organic coatings, composite epoxy resin coatings containing different concentrations (e.g., 5 wt%, 10 wt% and 20 wt%) of urea-formaldehyde (PUF) microcapsules were deposited on the top of Q235 carbon steel. The features of PUF microcapsules and composite coatings were characterized, and the corrosion behaviors of the coating-protected carbon steel were investigated in NaCl solution. The results showed that the spherical PUF microcapsules (∼40 μm) with 290 nm thick shell and hexyl acetate core are synthesized through in situ polymerization. The prepared microcapsules can uniformly distribute within the epoxy resin coatings, which in turn deteriorates the corrosion resistance of the microcapsules-containing composite coatings (MCECs). Lower volume (5 wt%) microcapsules incorporation caused a slight reduction in the corrosion resistance (Rc) and effective capacitance (Ceff) from 4.39 × 107 Ω·cm−2 and 6.50 × 10−5 mF·cm−2 to 8.72 × 106 Ω·cm−2 and 5.63 × 10−5 mF·cm−2, respectively. For higher volume (10 wt% and 20 wt%) groups, the Rc further decreases to 7.47 × 105 Ω·cm−2 and 1.45 × 105 Ω·cm−2, whereas the Ceff increases to 5.63 × 10−5 mF·cm−2 and 5.63 × 10−5 mF·cm−2, respectively. The failure mechanism of the MCECs can be ascribed to the rupture of the PUF microcapsules during the curing process and/or immersion in NaCl electrolyte, which suggested the mechanical strength and chemical stability of the capsules should be carefully determined to avoid their negative impact on the barrier property of polymeric coatings.

Synthesis of polymeric superhydrophobic coatings of nickel stearate for excellent corrosion resistance, self-cleaning, and photodegradation

Superhydrophobic coatings (SHCs) have been widely reported for various applications; however, the practical applications of SHCs have been restricted by recurrent preparation methods, complex equipment, and low mechanical robustness. The development of a simple, low-cost, and effective superhydrophobic coating remains a challenge. Here, we reported a simple way to fabricate the SHC by using fluoropolymeric suspension of nickel stearate nanoparticles (Ni-St-NPs) on the copper and other substrates. The surface of copper coated by SHC showed a static contact angle of 161 ± 1º and a sliding angle of 2º. Scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometer were used to determine the surface morphology, elemental content, crystal structures, chemical bonding, and structure of the SHCs. The fluoropolymeric coating of Ni-St-NPs showed excellent anti-corrosion and self-cleaning with mechanical durability and stability. Photodegradation of methylene blue (MB) and rhodamine B (RhB) dyes were done at 25 °C and obtained the degradation efficiency of 99 % and 98.1 %, respectively. The existence of self-cleaning, mechanical durability, and photocatalytic properties makes the fluoropolymer coating of nickel stearate a very promising superhydrophobic coating material for multifunctional applications.