Designing Hybrid Mesoporous Pr/Tannate-Inbuilt ZIF8-Decorated MoS2 as Novel Nanoreservoirs toward Smart pH-Triggered Anti-corrosion/Robust Thermomechanical Epoxy Nanocoatings

Preparation of polylactic acid/chitosan oligosaccharide films loaded metal-organic framework composite L-theanine and eugenol and its antibacterial and antioxidant properties

In this study, based on the porous characteristics of the metal-organic framework, the inclusion complex of L-theanine (L-the) and Eugenol (Eug) was prepared, and polylactic acid (PLA)/chitosan oligosaccharide (CSO) was used as polymer scaffold to fabricate fibrous films by electrospinning. The results showed that with the addition of inclusion complexes, the solution viscosity and the diameter of the fiber increased, the thermal stability improved, hydrophobicity enhanced, water vapor permeability reduced, mechanical properties destroyed, and brittleness increased. The surface of the plate inhibition zone showed a high inhibition effect on Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Botrytis cinerea (B. cinerea). With the increase of inclusion complexes' concentration, the fiber film could effectively inhibit the mildew of fruits, reduce the loss of Vitamin C (VC) and total phenol contents (TPC), and significantly prolong the storage period of fruits, having an excellent fruit preservative effect.

Ti3C2Tx MXene/MoS2 hybrid nanocomposites for synergistic smart corrosion protection of epoxy coatings

MXene nanosheets have recently become a focus of research for corrosion protection due to their two-dimensional, sheet-like structure and distinct physicochemical characteristics. Nevertheless, their susceptibility to restacking and oxidation restricts their practical applications. To address this, the study proposes a custom hybrid structure by growing molybdenum disulfide (MoS2) nanoparticles on the Ti3C2 MXene nanosheets (MX/MS) to prevent oxidation and restacking. This innovative structural design is essential for corrosion-protective coatings, as the sheet-like configuration enhances the barrier properties. The manufacturing of the MX/MS nanoparticles was verified by their characterization employing field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The barrier properties and self-healing functions of the nanoparticle-filled epoxy coatings were evaluated using electrochemical impedance spectroscopy (EIS) and salt spray tests. The epoxy resin including 0.5 wt% MX/MS nanoparticles exhibited outstanding corrosion resistance, with an impedance value (|Z|0.01Hz) of 23.77 GΩ.cm2 after 70 days of immersion. After 48 h of immersion, the coatings also showed a high impedance value (log|Z|0.01Hz = 4.24) and excellent self-healing capabilities in the scratched areas. Additionally, after 42 days, the filled nanohybrid coatings showed the least amount of rust and corrosion product according to salt spray analysis. The results of cathodic delamination and pull-off tests indicated that in comparison to the neat epoxy (11 mm and 70 %), the filled coatings containing the synthesized nanofiller had the lowest cathodic delamination radius (1.7 mm) and lowest adhesion loss (46 %). This study highlights the effectiveness of Ti3C2/MoS2 hybrid in enhancing the anticorrosive performance of organic coatings, offering a novel approach for designing high-performance additives with promising applications in various fields requiring corrosion protection.

Ultra-stable metal-organic framework-derived carbon nanocontainers with defect-induced pore enlargement for anti-corrosive epoxy coatings

Zeolitic imidazolate frameworks-8 (ZIF-8) have recently gained attention as nanocontainers for encapsulating corrosion inhibitors. However, two main challenges remain unsolved, casting doubt on their suitability as nanocontainers. The first challenge is their instability in acidic and basic environments, leading to structural decomposition and the second challenge is their mass diffusion limitation caused by micropore dominance and a small aperture size of 0.34-0.42 nm, limiting the efficient adsorption of corrosion inhibitors. To address both challenges, in this work, ZIF-8 nanostructures were transformed into nitrogen-doped ZIF-derived carbon-based nanocontainers (CZIF) via carbonization. This transformation not only stabilized the structure but also produced larger pore sizes (micro and mesopores), due to defects formed during carbonization. Benzotriazole (BTA) corrosion inhibitors were then encapsulated in CZIF structures to produce CZIF-BTA. Electrochemical impedance spectroscopy (EIS) demonstrated that the saline solution containing CZIF-BTA extract reduced the corrosion rate of steel by 50 % compared to a blank solution. The scratched epoxy (EP) coating containing 0.2 wt% of CZIF-BTA revealed an active inhibition performance with ∼100 % enhancement in the total resistance value compared to blank EP. Finally, the coating showed superior barrier properties with the impedance at the lowest frequency value of ∼2 × 1010 Ω cm2 after 71 days of immersion.

Improvement of the Abrasion and Corrosion Resistance of a Waterborne Epoxy Coating by α-ZrP@PTA-Ce(III) with Dual Corrosion Inhibition Effects

The introduction of poly(tannic acid) (PTA) and cerium ion [Ce(III)] on the surface of α-zirconium phosphate (α-ZrP) endowed the α-ZrP@PTA-Ce(III)/waterborne epoxy composite coating with enhanced corrosion protection and wear resistance performances. The successful preparation of α-ZrP@PTA-Ce(III) was confirmed through X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra. PTA improved the compatibility between α-ZrP@PTA-Ce(III) and the waterborne epoxy resin due to the presence of organic groups from tannic acid. The wear resistance test indicated that the incorporation of α-ZrP@PTA-Ce(III) effectively reduced the coefficient of friction and the wear rate. Electrochemical impedance spectroscopy was used to analyze the corrosion protection performance of unbroken coatings and the self-healing ability of scratched coatings. The incorporation of α-ZrP@PTA-Ce(III) improved the protection performace distinctly. In addition, α-ZrP@PTA-Ce(III) endowed the composite coating with dual corrosion inhibition effects, originating from the PTA film, to prevent the penetration of corrosive media and a dense film that came from the Ce(III) cation. The waterborne epoxy system with enhanced corrosion and wear resistance in this paper broadens the application of α-ZrP.

Step-by-Step Tuning of Tribological and Anticorrosion Performance of Zinc Phosphate Conversion Coatings through Effective Integration of Spherical P-Doped MoS2 Nanoparticles

Surface coatings with enhanced mechanical stability, improved tribological performance, and superior anticorrosion performance find immense application in various industrial sectors. Herein, we report the development of multifunctional composite zinc phosphate coatings by the effective integration of a structurally and morphologically tuned P-doped MoS2 nanoparticle additive (3P-MoS2) into the zinc phosphate matrix to offer attractive characteristics suitable for industrial applications. The integration of spherical nanoparticles as additive leads to the formation of homogeneous and compact coatings with a densely packed crystalline microstructure having enhanced microhardness, distinctive leaf-like morphology, and comparatively smooth topographical features. The attractive lubricity of the additive (3P-MoS2), coupled with its spherical morphology, facilitates a transition from sliding to rolling friction and contributes significantly toward the performance enhancement of the tuned composition of the composite zinc phosphate coating (0.3-PMS). Thus, the tuned 0.3-PMS coating delivers the lowest specific wear rate (1.334 × 10-5 mm3/Nm) and coefficient of friction (0.114) that significantly outperform bare-zinc phosphate coating. Further, the electrochemical corrosion study results indicate the improvement in corrosion resistance behavior of the composite zinc phosphate coatings with reduced corrosion current density (icorr) and charge transfer resistance (Rct) values, as compared to the bare-zinc phosphate coating. The effect of passivation in conjunction with the barrier protection characteristics of the composite coatings induced by the optimal composition of the integrated additive nanoparticles (3P-MoS2) can efficiently prevent the infiltration of corrosive ions and thereby significantly reduce the rate of corrosion.

2D materials for Tribo-corrosion and -oxidation protection: A review

The recent rise of 2D materials has extended the opportunities of tuning a variety of properties. Tribo-corrosion, the complex synergy between mechanical wear and chemical corrosion, poses significant challenges across numerous industries where materials are subjected to both tribological stressing and corrosive environments. This intricate interplay often leads to accelerated material degradation and failure. This review critically assesses the current state of utilizing 2D nanomaterials to enhance tribo-corrosion and -oxidation behavior. The paper summarizes the fundamental knowledge about tribo-corrosion and -oxidation mechanisms before assessing the key contributions of 2D materials, including graphene, transition metal chalcogenides, hexagonal boron nitride, MXenes, and black phosphorous, regarding the resulting friction and wear behavior. The protective roles of these nanomaterials against corrosion and oxidation are investigated, highlighting their potential in mitigating material degradation. Furthermore, we delve into the nuanced interplay between mechanical and corrosive factors in the specific application of 2D materials for tribo-corrosion and -oxidation protection. The synthesis of key findings underscores the advancements achieved through integrating 2D nanomaterials. An outlook for future research directions is provided, identifying unexplored avenues, and proposing strategies to propel the field forward. This analysis aims at guiding future investigations and developments at the dynamic intersection of 2D nanomaterials, tribo-corrosion, and -oxidation protection.

2D Nanomaterials Reinforced Organic Coatings for Marine Corrosion Protection: State of the Art, Challenges, and Future Prospectives

2D nanomaterials, with extraordinary physical and chemical characteristics, have long been regarded as promising nanofillers in organic coatings for marine corrosion protection. The past decade has witnessed the high-speed progress of 2D nanomaterial-reinforced organic composite coatings, and plenty of breakthroughs have been achieved as yet. This review covers an in-depth and all-around outline of the up-to-date advances in 2D nanomaterial-modified organic coatings employed for the marine corrosion protection realm. Starting from a brief introduction to 2D nanomaterials, the preparation strategies and properties are illustrated. Subsequently, diverse protection models based on composite coatings for marine corrosion protection are also introduced, including physical barrier, self-healing, as well as cathodic protection, respectively. Furthermore, computational simulations and critical factors on the corrosion protection properties of composite coatings are clarified in detail. Finally, the remaining challenges and prospects for marine corrosion protection based on 2D nanomaterials reinforced organic coatings are highlighted.

Developments in anticorrosive organic coatings modulated by nano/microcontainers with porous matrices

The durability and functionality of many metallic structures are seriously threatened by corrosion, which makes the development of anticorrosive coatings imperative. This state-of-the-art survey explores the recent developments in the field of anticorrosive organic coatings modulated by innovations involving nano/microcontainers with porous matrices. The integration of these cutting-edge delivery systems seeks to improve the protective properties of coatings by enabling controlled release, extended durability, targeted application of corrosion inhibitors, and can be co-constructed to achieve defect filling by polymeric materials. The major highlight of this review is an in-depth analysis of the functionalities provided by porous nano/microcontainers in the active protection and self-healing of anticorrosive coatings, including their performance evaluation. In one case, after 20 days of immersion in 0.1 M NaCl, a scratched coating containing mesoporous silica nanoparticles loaded with an inhibitor benzotriazole and shelled with polydopamine (MSNs-BTA@PDA) exhibited coating restoration indicated by a sustained corrosion resistance rise over an extended period monitored by impedance values at 0.01 Hz frequency, rising from 8.3 × 104 to 7.0 × 105 Ω cm2, a trend assigned to active protection by the release of inhibitors and self-healing capabilities. Additionally, some functions related to anti-fouling and heat preservation by nano/microcontainers are highlighted. Based on the literature survey, some desirable properties, current challenges, and prospects of anticorrosive coatings doped with nano/microcontainers have been summarized. The knowledge gained from this survey will shape future research directions and applications in a variety of industrial areas, in addition to advancing smart corrosion prevention technology.

Design Polyaniline/α-Zirconium Phosphate Composites for Achieving Self-Healing Anti-Corrosion of Carbon Steel

The rupture of a micro/nano container can trigger the release of repair agents and provides the coating with a self-healing and anti-corrosion effect. However, the defect and inhomogeneity of the coating, produced by the rupture of the micro/nano container, may weaken its anti-corrosion performance. This study reports a rare protection mechanism, which optimizes the space occupying of zirconium phosphate, and the de-doping peculiarity of polyaniline without the rupture of the micro/nano container. Polyaniline/α-zirconium phosphate composites were constructed through in situ oxidation polymerization. Repair agents were added in the form of doped acids. According to the different repair agents in polyaniline/α-zirconium phosphate composites (citric ion, tartaric ion and phytic ion), the performance and protection mechanism of the composites were researched. Polyaniline/α-zirconium phosphate coating (with phytic ion) shows an excellent self-healing anti-corrosive effect, due to the large spatial structure and abundant chelating groups of the precipitation inhibitor. Considering the anti-corrosive application, the developed polyaniline/α-zirconium phosphate composite has a far-reaching influence on marine development.