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The purpose of this investigation was to study the corrosion protection and structural characteristics of a hybrid organic-inorganic thin film preloaded with green corrosion inhibitor for anticorrosive protection of stainless steel 304L.

An ethanol solution of the polymerized 3-methacryloxypropyltrimethoxysilan and tetraethylorthosilicate was mixed with henna extract to give homogeneous sols. The morphology, composition and adhesion of hybrid sol-gel coatings were examined by SEM, EDX and pull-off tests, respectively. The surface chemistry of the hybrid sol-gel coatings was investigated with polarization scans and electrochemical impedance spectroscopy (EIS) in the physiological saline solution.

The polarization curves and EIS data were in agreement. Henna extract additions significantly increased the corrosion protection capability of the sol-gel thin film to greater than 85 percent in the physiological saline solution. In addition, the doped hybrid coating on stainless steel 304L was useful in 3.5 percent NaCl solution.

There have been few reports on the hybrid organic-inorganic thin films preloaded with corrosion inhibitor, as described in the paper, and this environmentally friendly coating on stainless steel 304L was found to be highly effective for industrial applications.

The purpose of this paper is to study the corrosion of carbon steel without coating and when protected using three different hybrid coatings, i.e. a bi‐component polyurethane with nano‐particles of SiO₂ with and without sacrificial anode particles, and a mono‐component polyurethane with SiO₂ particles.

In this investigation three different nano‐structured coatings are developed and applied to steel substrates and then tested for their corrosion resistance (defined as “R_n”), under a very aggressive medium (pH=1.5) in a dynamic system (loop reactor). Their performance is evaluated using an electrochemical noise (EN) resistance technique. The electrodes are connected to a potentiostat and measurements are recorded as per the EN technique over a 2,048 s duration at 0, 24, and 48 h intervals. Scanning electron microscopy (SEM) are obtained before and after the corrosion trials to characterize the control and the different coating systems.

The results show that a bicomponent coating, made up of alkyd resin and silica nanoparticles demonstrated the best performance, whereas the coating formed by SiO₂ nanoparticles and polyurethane resin showed relatively low corrosion resistance. The inclusion of zinc nanoparticles in a third coating as sacrificial nano‐anodes led to segregation and resulted in moderate corrosion resistance. These results are confirmed by SEM observations.

The results obtained in this paper provide an insight to the understanding of the anticorrosion properties of three different hybrid coatings in a dynamic system (loop reactor).

The purpose of this study is to prepare copper oxide nanoparticles (CuO NPs) in an easy and efficient way using a natural and environmentally friendly substance like ascorbic acid. Various concentrations of these nanoparticles were then added to solvent-free coating formulations to produce highly hydrophobic, corrosion-resistant and antimicrobial hybrid coatings. These hybrid formulations were also used to coat the spent fuel casks for their integrity.

The hybrid coated films were then characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), water contact angle and Scanning electron microscope (SEM). In addition, different measurements, namely, mechanical, physical, chemical, thermal, corrosion tests, open circuit potential and antimicrobial activity of these hybrid films were performed.

The results showed that the copper oxide was prepared at nanometer scales with good homogeneity and diffusion in the epoxy acrylate matrix. It also showed that some hybrid coatings have high corrosion resistance, strong hardness, excellent water resistance, remarkable antimicrobial activity and high thermal stability compared to virgin epoxy acrylates.

The formula containing 0.5% CuO NPs was found to provide the highest corrosion protection and antimicrobial activity for mild steel in 3.5% sodium chloride (NaCl).

This study aims to report the development and experimental evaluation of three innovative corrosion-resistant modified epoxy coatings, namely, nanocomposite/toughened, self-healing and hybrid epoxy coatings, for application on steel substrates.

The corrosion resistance of these coatings was evaluated in a highly corrosive environment of salt fog spray for 2,500 h of exposure. Electrochemical impedance spectroscopy (EIS) measurements in sustained exposure to NaCl in a saturated Ca(OH)2 solution, rust creepage measurements at the location of scribe formed in the coatings and adhesion strength test were used to assess the performance of the innovative coatings. Commercially available marine-grade protective epoxy coatings were used as the reference coatings.

The test results showed that the modified epoxy coatings exhibited excellent corrosion resistance when exposed to an aggressive environment for extended periods. The EIS measurements, rust creepage measurements, pull-off strength and visual appearance of the aged modified–epoxy–coated specimens confirmed the enhanced corrosion resistance of the modified epoxy coatings.

Among the three types of modified coatings, the hybrid epoxy coating stands out to be the best performer.

The purpose of this paper was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5 per cent NaCl solution. The search for replacing chromates in protective coatings has led to the development of hybrid sol-gel anticorrosive coatings. Appropriate functionalization can dramatically enhance the chemical durability and mechanical strength of these coatings.

To prepare the targeted coating, 1,2-epoxybutane (EB) was mixed with 2 to 4 per cent aminoethylaminopropyl-methylsiloxane dimethylsiloxane (APDMS) copolymer and 1,6-diaminohexane. The above coating (EBAC) has been further mixed with three different corrosion inhibitors “Moly-white® 101-ED, Heucophos Zapp® and cerium ammonium nitrate”, yielding the coatings EBAC-M, EBAC-Z and EBAC-Ce, respectively. The corrosion characteristics of all coatings on the steel panels immersed in 3.5 per cent NaCl solution were obtained using different electrochemical methods such as electrochemical impedance spectroscopic and Tafel polarization measurements.

The newly prepared coatings showed interesting protection properties for protecting the steel substrate against corrosion in chloride-containing media.

The results provide a good approach for the modification of polydimethylsiloxane coatings using a simple organic modifier.

The purpose of this work was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5 per cent NaCl solution. The search for replacing chromates in protective coatings has led to the development of hybrid sol-gel anticorrosive coatings. Appropriate functionalization can dramatically enhance the chemical durability and mechanical strength of these coatings.

To prepare the targeted coating, 1,2-epoxybutane (EB) was mixed with 2-4 per cent aminoethylaminopropyl-methylsiloxane dimethylsiloxane copolymer and 1,6-diaminohexane. The above coating (EBAC) was further mixed with three different corrosion inhibitors “Moly-white® 101-ED, Hfucophos Zapp®” and Cerium Ammonium Nitrate, yielding the coatings (EBAC-M), (EBAC-Z) and (EABC-Ce), respectively. The corrosion characteristics of all coatings on carbon steel panels immersed in 3.5 per cent NaCl solution were obtained using different electrochemical methods such as electrochemical impedance spectroscopic and Tafel polarization measurements.

The newly prepared coatings showed interesting properties for protecting the steel substrate against corrosion in chloride containing media.

The results provide a good approach for the modification of polydimethylsiloxane coatings using a simple organic modifier.

This study aims to propose that the corrosion resistance of the neat epoxy coating can be further enhanced by incorporating reinforcing agents.

Chitosan, silica and their hybrid compound were used to study the subject of corrosion resistance of epoxy coating systems. This work used 3.5 Wt.% NaCl solution as the electrolyte, and electrochemical impedance spectroscopy (EIS) was used to investigate the electrochemical behaviour of the studied coating systems. Standard and accelerated states were used without and with scratch on the coating layer.

It was found that the impedance value of composite coating incorporated with the hybrid compound was significantly higher at 10¹⁰ Ω after 14 days of exposure in both testing states. The breakpoint frequency (f_b) determination also proves with large capacitive region at low-to-high frequency of impedance plots corresponding to the high corrosion resistance.

The hybrid compound consisting of chitosan as organic biopolymer and silica as inorganic material, respectively, served as a promising reinforcing agent for composite coating as a promising corrosion inhibitor. Different states of EIS measurement were used which are standard (without scratch) and accelerated (with scratch) states associated with the f_b values.

The main aim of this study was to examine the effects of chicken eggshell (CES) and rice husk ash (RHA) as fillers on the mechanical and the thermal insulation properties of polyurethane coatings.

CES and RHA were ground via ball milling set at different parameters, and the smallest particles size obtained were selected and used as fillers. Fillers of different weight proportions were mixed with other components such as binder, solvent and pigment to form various coating formulations and test samples were made via dip coating. A series of characterisations were conducted to analyse the thermal and mechanical properties of the coating.

The smallest particle size of CES and RHA was obtained after both of them had undergone grinding process at 400 rpm within 180 min. Morphological studies revealed that CES and RHA have irregular shape and high porosity. In crystallographic analysis, CES mainly composed of pure calcite crystal structure and RHA contained amorphous silica. Both of fillers were found thermally stable up to 520 and 710°C for RHA and CES, respectively. In RHA individual system, as the RHA proportion increases, the thermal conductivity of the coating declined. In contrast, in the CES coating system, the thermal conductivity demonstrated an opposite trend. Thermal gravimetric analysis results displayed that by adding hybrid fillers, the residue weight and the thermal stability of the coatings were increased. In addition, the adhesion strength of the coating was increased as the filler weight content increased.

Fillers with nano-range size were expected to be produced in this research for better performance of the coating. However, the obtained fillers were limited to micron size through dry grinding method. Another drawback in this research was the coating technique which is dip coating. The coated substrates do not have uniform coating thickness and this subsequently influenced the performance.

A novel attempt has been made to study the formulation coating system by mixing CES and RHA as fillers which is also known as a hybrid system.

The purpose of this study is to prepare a polydopamine (PDA)–palygorskite (Pal) hybrid-reinforced epoxy coating with high adhesion strength on wet concrete surface.

One synthetic step was adopted to prepare novel PDA–Pal hybrid epoxy coating. The process and product were analyzed and confirmed by FIRT, thermogravimetric analysis and scanning electron microscopy. The mass fraction of PDA–Pal hybrid affecting the adhesion strength of epoxy coating was analyzed and confirmed by pull-off test.

PDA–Pal hybrid mass fractions of 0, 1, 3 and 5 were added to the coatings. For a 5 Wt.% PDA–Pal hybrid content, the adhesive strengths on the saturated or underwater concrete surfaces increased to 4.0 and 2.5 MPa, respectively. In addition, the tensile mechanical property of the epoxy coating improved significantly after PDA–Pal addition.

This new epoxy coating hybrid by PDA–Pal could be applied as a concrete protective layer near water or in wet or damp environments.

Introduction of PDA–Pal hybrid to prepare epoxy coating with high adhesion strength on wet concrete surface has not been systematically studied previously.

The purpose of this paper is to develop a volatile organic component‐free water‐based binder with improved coating properties from urethane‐alkyd acrylate by emulsion polymerisation.

Alkyd resin based on interesterification of sardine fish and linseed oil (50:50 w/w) was synthesised and reacted with isophorone diisocyanate to form urethane alkyd. The resultant urethane alkyd and acrylic monomers in different ratios were polymerised by emulsion polymerisation to form air‐drying water‐based binders and studied for physicochemical and other coating properties.

Urethane alkyd, co‐polymerised with acrylates by emulsion polymerisation process, can be used to prepare water‐based air‐drying binders with excellent coating and application performance. The increase in acrylate component in the system resulted in improvement of performance properties.

In the present study, refined fish oil (FO) was obtained from sardine fish. Different FOs can be used to produce alkyd resin. Urethane alkyd and acrylic monomers in different ratios can be polymerised by emulsion polymerisation techniques.

The emulsion polymerisation is the most effective technique used to produce water‐based binders with excellent coating properties.

Water‐based binders can be widely used in exterior coatings and waterproofing of cement and roofs.