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• Efficient high-solids, one-coat paints were synthesized for AA2024 through sol-gel method. • Strong chemical interaction with enhanced cross-linking density can be achieved in silicone-epoxy-silica coating. • The hybrid coating presented an impedance modulus of GΩ after 628 h immersion with a thickness of less than 20 μm. • Char residue of the hybrid coating was increased to more than 40% by the addition of HTEOS to silicone-epoxy coating. • The high solids hybrid coating displayed improved impact resistance and good flexibility. A hybrid organic-inorganic coating was prepared with silicone-epoxy coating and prehydrolyzed TEOS (HTEOS) through the sol-gel process. This study aimed to study the effect of HTEOS on the corrosion protection performance of hybrid coatings on AA2024 alloy. The obtained hybrid coatings were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and water contact angle tests. The impact resistance of the coatings was estimated by the cupping test. Electrochemical impedance spectroscopy (EIS) and scanning vibration electrochemical technology (SVET) tests were used to evaluate the corrosion resistance of the hybrid coating. With the presence of 4 wt% HTEOS, the hybrid coating showed better corrosion resistance and impact resistance. The superior protection of the hybrid coating with 4 wt% HTEOS could be attributed to the enhanced Si O Si network and higher proportion of the inorganic phase. [ABSTRACT FROM AUTHOR]

Abstract: Organic–inorganic hybrid materials can be defined as materials combining organic and inorganic domains in a nanometric scale. The development of these organic–inorganic hybrids has achieved properties from both organic and inorganic materials. In this research we have studied the scratch behaviour of coatings of organic–inorganic hybrid materials prepared by sol–gel processing, using as precursors, trialkoxysilanes with organic functionalities that react via free radical polymerization. We have also evaluated the influence of pure inorganic precursor as tetralkoxysilanes or pure organic precursors on the scratch behaviour. The main goal of this research was to evaluate how the chemical structure of the organic–inorganic hybrid influences the scratch behaviour of the coatings. [Copyright &y& Elsevier]

Transparent hard-coating materials with glass-like wear resistance and plastic-like flexibility have attracted attention owing to their applicability in flexible/foldable displays. Materials with wear-resistant and bendable properties are rare because inorganic materials are normally hard and brittle, whereas organic materials, although flexible, typically lack wear resistance. This study entailed the development of a flexible hard coating, prepared by crosslinking a cycloaliphatic epoxy-functionalized oligosiloxane (CEOS) and hydroxylic-functionalized acrylic polymer with phthalic anhydride (PA) to form a highly crosslinked organic–inorganic coating network. CEOS, a UV-curable high-hardness inorganic base coating material, was synthesized by a sol–gel reaction. Thermally curable acrylic polymer and PA as a crosslinker were then introduced to simultaneously improve flexibility and hardness. Two differently curable materials were blended to maximize the coating properties through the synergistic effect of the different curing characteristics. To optimize the curing system, a dual-curing process involving UV irradiation and heat treatment was introduced. In the first step, UV irradiation initiated the ring-opening polymerization of the epoxide rings of CEOS. In the second step, the epoxide ring of CEOS, the hydroxylic group of the acrylic polymer resin, and the anhydride group of PA were thermally cured, and a multi-crosslinked network coating film was fabricated. The prepared coating exhibited high hardness (nano-indentation hardness of 0.63 GPa and a pencil hardness of up to 8H) and outstanding optical transparency (up to 91 % at 500 nm). The coated layer on the PET film exhibited high flexibility and could be bent to form a U-shaped cross-section without coating damage. [Display omitted] • Highly crosslinked organic–inorganic hybrid coating network formed • Dual-curing process involving UV irradiation and heat treatment was optimized. • High flexible hard coating for flexible/foldable displays was developed. • Coating is transparent with glass-like wear resistance and plastic-like flexibility. [ABSTRACT FROM AUTHOR]

As an abundant natural resource, bamboo with enhanced flame retardancy and mildew resistance after surface treatment has a wider range of applications. Although several organic or metal oxide coatings have been used on bamboo, their basic properties such as transparency and durability are neglected, which limits their practical application. Herein, we prepared a new organic–inorganic coating by thermal curing between vanillin-derived epoxy (VEP) and hyperbranched siloxane (HPSi). The curing process of VEP/HPSi coating was analyzed with FTIR. When the mass ratio of VEP and HPSi was 20:28, the obtained Schiff base hybrid coating exhibited visible light transmittance over 90% and the highest pencil hardness of 9H. The mechanical properties of the coating were investigated by nanoindentation (hardness: 0.208 GPa, elastic modulus: 2.677 Gpa) and impact test. Impressively, the fabricated coating showed remarkable solvent wipe resistance (Xylene and ethanol: 1000 cycles) and continuous abrasion (cheesecloth test: 5000 cycles). In addition, the hydrophobic and dense coating endowed the coated bamboo excellent mildew resistance even in high humidity (97%). Due to the high thermal stability, the coated bamboo presented a significant enhanced flame resistance with a limiting oxygen index value of 29.1%. From a broader perspective, the Schiff base hybrid coating with excellent comprehensive performance and facile preparation process display great potential for practical application for bamboo or other substrates. [Display omitted] • VEP is obtained from renewable Vanillin and HPSi is easy-to-get from KH550. • The Schiff base hybrid coating has high transparency and the 9H pencil hardness. • The coated bamboo exhibits enhanced mildew resistance and flame retardancy. [ABSTRACT FROM AUTHOR]

Thousands of deaths related to infectious diseases caused by bacteria are reported yearly within the EU. The spread of such microorganisms is often associated with the personal contact with infected surfaces, which can be avoided by the deposition of coatings with self-cleaning or germicidal properties. Therefore, the hydrophobic character of the oligosilazane Durazane 1800 was combined with the germicidal properties of copper(II)acrylate in a hybrid organic/inorganic coating. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) of the hybrid coatings on AISI 304 steel confirmed the homogeneous distribution of Cu and Si in a molar ratio of 0.3 (Cu:Si) within a dense and well-adherent 4 μm thick layer after annealing at 135 °C for 24 h in air. The good adhesion (GT 2) and scratch tolerance (20 N) of the coatings were respectively attributed to the formation of Si-O-Fe bonds between the silazane and the substrate and to the polymeric character of the hybrid system. The exposure of -CH 3 and -CH=CH 2 hydrophobic groups of the silazane to the surface of the coating system was responsible for its hydrophobic character, resulting in a contact angle of 99.8° with water. Its germicidal potential was comparable to pure copper as confirmed by live/dead assay tests, where the number of living bacteria was reduced over 99%, which can be correlated to the release of Cu2+ ions from the coating. A direct cell count technique was used to measure the influence on bacterial colonization. Furthermore, the material exhibited an enhanced chemical resistance during exposure to isopropanol and concentrated H 2 O 2 (30 wt%) for 24 h, leading only to minimal signs of degradation. • Novel thin hybrid copper(II)acrylate/silazane polymeric coatings • Hydrophobic coatings with self-cleaning properties • Killing of 99.99% of bacteria during live dead assay test • Antibacterial coatings with a biocidal potential comparable to elemental copper • High mechanical stability and enhanced resistance against concentrated germicides [ABSTRACT FROM AUTHOR]

Abstract: This study is focused on corrosion protection of magnesium alloy ZK10. The aim of the research was the production of a hybrid organic–inorganic coating that would be a combination of epoxy resin, organically modified silicates as well as conductive polymer. Furthermore, ceramic containers loaded with corrosion inhibitor were incorporated into the coating for the improvement of its corrosion protection properties. The composition and structure of the coatings were investigated by Fourier transform infrared spectroscopy, energy dispersive X-ray analysis and scanning electron microscopy. Extent of the anti-corrosion protection of the formed coatings was examined electrochemically using electrochemical impedance spectroscopy. The results showed that the incorporation of the containers loaded with inhibitor into the coatings improved their corrosion protection properties. Furthermore, artificial defects of 1mm were made to the coatings with the best anticorrosive performance in order to study the electrochemical processes taking place in the scratched area and to estimate the effect of the corrosion inhibitor in the corrosion of the substrate. [Copyright &y& Elsevier]

The combination of clay and intumescent, also termed hybrid organic−inorganic coating is an attractive strategy to improve the flame retardancy of polyurethane foam (PUF). However, the fabrication of such flame retardants remains challenging as it requires the deposition of many layers to achieve the desired level of the intumescing effect. Herein, we describe a facile route to fabricate a hybrid clay−intumescent coating comprising a OnePot−deposited chitosan (CH)−phytic acid (PA) polyelectrolyte complex (PEC) intumescent stacked on top of a layer-by−layer self−assembled clay trilayer (TL) of poly− d −lysine, CH, and alginate-stabilized montmorillonite. Combustibility tests using cone calorimetry revealed that a PUF coating of CH−PA PEC intumescent on a 5 TL clay nanobrick wall (CH−PA@5 TL@PUF) can reduce the peak heat release rate (a critical flammability metric), peak rate of smoke release, and peak CO 2 production rate of neat PUF by 73%, 33%, and 65%, respectively. Additionally, this hybrid coating imparted UL−94 horizontal burning rating by avoiding melt dripping and flashover, while the neat foam was completely consumed during the UL−94 flammabilty test. The proposed method is adaptable for the facile construction of other multifunctional surfaces in various application fields. [Display omitted] • Facile, environmentally-friendly, and effective flame retardant coating of polyurethane foam, one of the first items that quickly ignites in the event of a fire. • Environmentally benign layer-by-layer assembly to deposit a few multilayers of clay, combined with the OnePot-deposited chitosan/phytic acid polyelectrolyte complex intumescent layer. • Significantly enhanced flame retardancy of PUF with minimizing coting time and simplifying the coating process. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrids are considered an effective and environmentally compliant alternative to chromate-based anticorrosive coatings, currently banned due to the high toxicity of hexavalent chromium. In this work, hybrid nanocomposites based on poly(methyl methacrylate) (PMMA), covalently bonded to cerium oxide nanoparticles through the 2-hydroxyethyl methacrylate (HEMA) coupling agent, were tailored by carefully tuning the inorganic colloidal precursor to provide films with active corrosion protection for metallic substrates. Lithium hydroxide was exploited as oxidizing agent of cerium nitrate to form ceria nanoparticles. Precursor solutions and solid nanocomposites with different LiOH to Ce(NO 3) 3 .6H 2 O molar ratios were analyzed using spectroscopic and electron microscopy techniques and theoretical simulations. Electrochemical impedance spectroscopy (EIS) was used to study the anticorrosive performance of the coatings on carbon steel and 7075 aluminum alloy. The results showed that increasing amounts of LiOH lead to the formation of higher ceria content and larger primary nanoparticles, ranging from 1.7 to 2.8 nm. The homogenous ~20 μm-thick coatings present excellent anticorrosive performance on carbon steel and AA7075 substrates. Coatings on carbon steel with low LiOH loading (1Li:1Ce) showed long-term durability and high impedance modulus of up to 29 GΩ cm2 after 1 day in saline solution. On the AA7075 alloy, the presence of larger cerium oxide particles at higher LiOH content (3Li:1Ce) acted as effective reservoirs of cerium ions, providing high barrier coatings (395 GΩ cm2) with active corrosion protection. [Display omitted] • LiOH was used as oxidizing agent of cerium nitrate to form ceria nanoparticles. • Homogenous distribution of CeO x nanoparticles in the PMMA matrix for Li:Ce = 1. • PMMA-cerium oxide coatings exhibited excellent anticorrosive performance. • Coatings containing higher CeO 2 content showed self-healing ability. • Active protection was achieved by Ce4+ depletion forming insoluble cerium species. [ABSTRACT FROM AUTHOR]