Nanocomposite Coatings for Anti-Corrosion Properties of Metallic Substrates

Enhancing corrosion resistance with chemically modified aluminum oxide in UV-curable coatings applied to steel surfaces

This study introduces a novel, environmentally sustainable epoxidized soybean oil acrylate (ESOA) nanocomposite coating containing nAl2O3-silane nanoparticles (ESOA@TMPTA-nAl2O3-Silane), which was fabricated using ultraviolet (UV) curing technology. As far as we know, this is the first study to incorporate aluminum oxide nanoparticles (nAl2O3) modified through covalent bonding with a reactive diluent monomer, tripropylene glycol diacrylate (TPGDA), and a coupling agent to enhance their dispersibility and interaction within the polymer matrix. Comprehensive characterization techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), UV-spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM), confirmed the nanocomposite's structural and polymer morphological enhancements. Electrochemical impedance spectroscopy (EIS) demonstrated a substantial increase in polarization resistance (Rp), rising from 25.6 kΩ cm2 for the unmodified polymer to 288.7 kΩ cm2 upon the incorporation of (8 wt%) nAl2O3-Silane. In a similar vein, Potentiodynamic polarization (PDP) exhibited a significant decrease in corrosion current density (icorr), diminishing from 0.82 to 0.059 µA/cm2, thereby achieving an inhibition efficiency exceeding 99%. Additionally, the salt spray test data showed a considerable improvement in the rust degree from 3 to 8G under identical conditions. The data demonstrates the outstanding corrosion resistance characteristics that the nAl2O3-Silane nanoparticles provided when coupled with the steel substrate. This improvement is attributed to the excellent dispersion, excellent barrier properties, transparency of the resulting coatings and strong adhesion of nAl2O3-Silane dispersed in the polymer matrix.

Enhanced organic matter removal and fouling mitigation in seawater desalination using electrocoagulation pretreatment using ZnO coated Fe electrodes

This study introduces a novel application of electrocoagulation (EC) as a pretreatment method for seawater desalination, uniquely focusing on reducing organic and biological fouling in reverse osmosis membranes. The EC process was investigated as an alternative to conventional approaches such as chemical coagulation, chlorination, and fouling inhibitors. EC was conducted in a batch cell using iron electrodes. The effectiveness of the EC process in removing organic matter from water was monitored by measuring absorbance UV254 and dissolved organic carbon (DOC), as well as total hardness. Various operational parameters, including mixing speed, current density, initial pH, and electrode spacing, were examined. Results demonstrated that increasing current density and decreasing pH enhanced the removal of organic matter from seawater via EC. The process achieved a 62% reduction in DOC and a 59.7% reduction in absorbance, indicating that higher current density is more favorable for these reactions. However, the reduction in total hardness was relatively low at approximately 11.2%, suggesting that EC is not suitable for reducing water hardness. Overall, the experimental findings highlight the high potential of electrocoagulation as a pretreatment method for mitigating organic and biological fouling of reverse osmosis membranes due to its effectiveness in removing dissolved organic matter and microorganisms from seawater.

Applications of MOF-Based Nanocomposites in Heat Exchangers: Innovations, Challenges, and Future Directions

Metal-organic frameworks (MOFs) have garnered significant attention in recent years for their potential to revolutionize heat exchanger performance, thanks to their high surface area, tunable porosity, and exceptional adsorption capabilities. This review focuses on the integration of MOFs into heat exchangers to enhance heat transfer efficiency, improve moisture management, and reduce energy consumption in Heating, Ventilation and Air Conditioning (HVAC) and related systems. Recent studies demonstrate that MOF-based coatings can outperform traditional materials like silica gel, achieving superior water adsorption and desorption rates, which is crucial for applications in air conditioning and dehumidification. Innovations in synthesis techniques, such as microwave-assisted and surface functionalization methods, have enabled more cost-effective and scalable production of MOFs, while also enhancing their thermal stability and mechanical strength. However, challenges related to the high costs of MOF synthesis, stability under industrial conditions, and large-scale integration remain significant barriers. Future developments in hybrid nanocomposites and collaborative efforts between academia and industry will be key to advancing the practical adoption of MOFs in heat exchanger technologies. This review aims to provide a comprehensive understanding of current advancements, challenges, and opportunities, with the goal of guiding future research toward more sustainable and efficient thermal management solutions.

Enhanced corrosion protection of copper in saline environments using bio-nanocomposite coatings based on chitosan and chitosan Schiff base

An in-depth study focuses on developing new environmentally friendly bio-nanocomposites, by incorporating SrTiO3 (STO) ceramic nanoparticles into matrices of chitosan and its derivatives, aiming to use them as protective coatings against corrosion. The various stages of this study include the cross-linking of chitosan, the synthesis of Schiff base chitosan, the cross-linking of Schiff base chitosan, and the preparation of nanocomposite coatings. The coatings' structure and composition were analyzed using different methods, including Fourier Transform Infrared Spectroscopy - Attenuated Total Reflectance (FTIR-ATR), X-ray Diffraction (XRD), Transmission Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (TEM-EDX), and Scanning Electron Microscopy (SEM). In addition, Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP) measurements were carried out to assess the inhibitory efficacy of chitosan crosslinked with epichlorohydrin (Cs-Ep), epichlorohydrin-crosslinked chitosan-salicylaldehyde Schiff base (CS-S-Ep) and CS-Ep-STO and CS-S-Ep-STO nanocomposite coatings, as well as the long-term protection durability of CS-S-Ep-STO. These techniques revealed a significant reduction in corrosion current density after chemical modification of chitosan and incorporation of SrTiO3 (STO) nanoparticles into CS-Ep and CS-S-Ep matrices, confirming a notable improvement in the inhibitory efficiency of these coatings against copper corrosion in a saline environment. Computational modeling methods like Density Functional Theory (DFT), Molecular Dynamics (MD), and Monte Carlo (MC) simulations reinforced these results by demonstrating efficient adsorption of CS-S-Ep-STO nanocomposites on metal surfaces through the interaction with heteroatoms present in the functional groups (-C=N-, -C-O-, -OH) and STO nanoparticles. The present study's findings provide key information for developing innovative protective coatings, highlighting the potential of chitosan-based nanocomposites and derivatives, particularly with SrTiO3 incorporation, in mitigating metal surface corrosion in aggressive environments.

Electrochemical Impedance Spectroscopy Analysis of Organic Epoxy Coatings Reinforced with Nano Clay

Electrochemical impedance spectroscopy (EIS) is a modern and efficient method for the evaluation of the protective abilities of coatings. However, the interpretation of the experimental data is a difficult task. This paper aims to investigate the effect of the addition of a nano clay, Cloesite 30B®, on the barrier properties of an epoxy-based system through electrochemical impedance spectroscopy in an aerated sodium chloride solution. The EIS spectra of the samples analysed showed different evolutions over time. The subsequent processing of spectra using equivalent electrical circuits is an excellent analytical tool and allows the protective capacity of coatings to be assessed. By using this analysis, it was possible to define and comprehend the impact of adding nano clay in different concentrations to the epoxy resin coating. The work has shown the effectiveness of increasing the barrier effect of the coating with this type of nano clay. However, the improvement is linked to obtaining a correct dispersion of nanoparticles. Otherwise, there is the formation of macro-clusters of particles inside the coating. Their appearance can cause a deterioration in coating performance.

Study on the Effect of Additives on the Performance of Cement-Based Composite Anti-Corrosion Coatings for Steel Bars in Prefabricated Construction

The influence of polymer emulsion, pigment filler, and dispersant on the corrosion resistance of polymer cement-based composite anti-corrosion coatings were investigated in this study. Adhesion loss rate tests and electrochemical tests were conducted on samples. The research results show that optimal corrosion resistance can be achieved with a 45 wt% dosage of emulsion, a 6 wt% dosage of pigment filler, and a 0.30 wt% dosage of dispersant. The bonding properties of bare steel bars, epoxy-coated steel bars, and polymer cement-based composite anti-corrosion coated steel bars with grout were compared. The results show that the polymer cement-based composite anti-corrosion coating can enhance the bonding properties of the samples. Furthermore, the microscopic analysis was conducted on the samples. The results demonstrate that the appropriate addition of emulsion can fill internal pores of the coating, tightly bonding hydration products with unhydrated cement particles. Moreover, incorporating a suitable dosage of functional additives enhances the stability of the coating system and leads to a denser microstructure.

Nanoceramic-based coatings for corrosion protection: a review on synthesis, mechanisms, and applications

Corrosion is a pervasive issue with significant economic and safety implications across various industries. Nanoceramic-based coatings have emerged as a promising solution for corrosion protection due to their unique properties and mechanisms. This review aims to comprehensively examine the synthesis, mechanisms, and applications of nanoceramic-based coatings for corrosion protection. The review begins by highlighting the importance of corrosion protection and its impact on different industries. It introduces nanoceramic-based coatings as a potential solution to address this challenge. The objective is to provide a thorough understanding of the synthesis methods, mechanisms, and applications of these coatings. The fundamental principles of corrosion and different corrosion mechanisms are discussed, along with the limitations of traditional corrosion protection methods. The review emphasizes how nanoceramic-based coatings can overcome these limitations and provide superior corrosion resistance. Various synthesis methods, including sol-gel, electrodeposition, and physical vapor deposition, are described in detail, along with the factors influencing the synthesis process. Recent advancements and innovations in nanoceramic coating synthesis techniques are also highlighted. This looks at how coatings made with tiny ceramic particles protect against corrosion. It examines the importance of small-scale details like particle size, shape, and what the particles are made of. The formation of passive layers, self-healing mechanisms, and barrier properties of nanoceramic coatings are explained. The diverse applications of nanoceramic coatings for corrosion protection in industries such as automotive, aerospace, and marine are comprehensively discussed. Case studies and examples demonstrating the significant corrosion resistance and improved performance achieved with nanoceramic coatings are presented.