The highly cross-linked epoxy cured network suffers from the brittle nature and poor elongation, which hinders many potential applications. In this study, a biology-based cardanol NC-514S-modified ...polyether amine D230 was synthesized and used as an epoxy hardener (NC-D230). The effects of NC-514S content on the mechanical and thermal properties of the prepared samples were investigated. At the same time, we used cyclic stretching to further characterize its mechanical strength, and characterized the curing agent before and after modification through SEM and FTIR. Mechanical tests on the samples showed that the increase of NC-514S content results in lower tensile strength and Young’s modulus but an increase in elongation-at-breaks. DSC and TGA analyses showed a decreasing trend of glass transition temperature with the addition of NC-514S. Typically, the epoxy thermoset without/with 75% (by wt) NC-514S-modified D230 decreased tensile strength from 61.7 to 17.74 MPa, and Young’s modulus from 496 to 11.56 MPa. It increased elongation from 13.43% to 97.97%, and decreased glass temperature from 87.5 to 51.9 °C by DSC and 87.8 to 54.7 °C by DMA, respectively. This novel bio-based renewable cashew phenol-modified polyetheramine may provide an ideal candidate for toughening an epoxy-based thermosetting materials. At the same time, it also provides a new way for the toughening of epoxy resin.
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Two tetrazole compounds (BTA, BTTA) self-assembled on copper substrate and their inhibition effect toward copper corrosion in 0.5 M H2SO4 was evaluated through atomic force microscopy (AFM), scanning ...electron microscopy (SEM), weight loss measurement along with electrochemical techniques including electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Results indicate that BTTA can provide superior inhibition performance to BTA, and the highest inhibition efficiency values of 96.3% (BTA) and 99.8% (BTTA) were achieved respectively at 2 mM. Both tetrazole inhibitor films follow Langmuir model concerning both physical and chemical adsorption, which can be verified by X-ray photoelectronic spectroscopy (XPS) analysis. Besides, the negative value of adsorption free energy infers a spontaneous adsorption process of these tetrazole compounds on Cu surface. Molecular dynamics (MD) simulation reveals stronger multiple anchor adsorption of BTTA molecules than BTA because of the existence of S atom.
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•An eco-friendly drug losartan potassium (LP) is developed as a superior mixed-type inhibitor for steel corrosion.•The multi-anchored film of LP is formed on steel ...substrate.•Theoretical modelling provides deep insights into the inhibition performance of LP.
The present study aimed to find a suitable alternative for traditional and hazardous corrosion inhibitors. A green antihypertensive drug-Losartan potassium (LP) with superior corrosion protection ability was developed for the first time. Gravimetric method, potentiodynamic polarization, AC impedance, and scanning vibrating electrode technique (SVET) were combined to evaluate the corresponding inhibition performance towards Q235 steel in HCl medium. The results indicated that LP exhibited superior mixed-type corrosion protection to steel at different temperatures owing to the formation of compact and ordered LP-adsorption film on steel surface. Specifically, the inhibition performance values increased to 88.9%, 91.8%, and 92.0% for 5 mM LP at 298, 308, and 318 K, respectively. Meanwhile, N-Fe bond from X-ray photoelectronic spectroscopy (XPS) implied multiple anchoring interaction between steel and LP with nitrogen atoms as active sites. Based on DFT calculation and molecular dynamics (MD) simulation, the obtained low energy gap (ΔE) and high Ebinding values as well as radial distribution function (RDF) analysis represented strong chemisorption of LP on Fe substrate, which theoretically explained the favorable inhibition effectiveness of LP compound at molecular or atomic level.
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The protective performance of graphene/polymer composite coatings largely depends on the interface design in resin matrix. Herein, we report the synthesis of bio-based cardanol epoxy ...modified graphene oxide (GODN) nanomaterial and its application in epoxy coatings for the achievement of fine interface toward high performance anticorrosion composite coatings. The chemical composition of prepared GODN nanomaterial was investigated by FTIR, Raman and XPS spectra, respectively. The presence of cardanol epoxy attached on GO surface promotes the formation of chemical bonds between GO and epoxy resin, providing strong interfacial interaction and enhanced adhesion. Electrochemical results revealed that the GODN1%/EP composite coating exhibits high impedance (4.38 × 108 Ω cm2) even after 45 days immersion. Compared with pure EP coating, the localized corrosion reaction of GODN1%/EP coating can be inhibited under defected interface. The enhanced protective performance of GODN/EP composite coating was attributed to two aspects: (1) the impermeable GO greatly suppressed the penetration of aggressive ions and (2) the attached cardanol epoxy chains effectively improved the interfacial interaction and thus inhibited the crack propagation.
Although extensive experiments confirm the ability of copper for biofouling protection, its further utilization is still limited in virtue of unclear relationship between the surface topography and ...antibacterial performance. In this study, the hydrophobic copper surfaces with different morphologies, including nanowire, nanowire/microflower, and nanosheet/microflower hierarchical structures, were prepared through the one-step chemically etched method and in-situ self-assembly strategy. According to the four-time cyclic antibacterial assays for E. coli and B. subtilis, the copper with nanowire structure displayed a better antibacterial performance than others. Bacteriostasis rate of nanowire structure copper was over 90% in the first cycle, and reached 100% in the final test. In addition, the morphologies of copper surfaces after antibacterial test suggested that nanowire and microflower structures could significantly suppress the adhesion of bacteria. Besides, nanowire structure exerted an outstanding function in inhibiting bacterial adhesion under a lower concentration of inorganic salt.
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•Hydrophobic copper surfaces with various surface morphologies were fabricated.•Copper surface with nanowire structures presented excellent performance in suppressing bacterial adhesion.•The antibacterial mechanisms of different morphologies were proposed.
Many functions of terrestrial plant leaves rely on the regenerable epidermal wax layer. Biomimetic autocrine waxy materials (AWMs) inspired by renewable epidermal waxes are attracting increasing ...attention. However, the growth properties of the wax layer remain unclear, limiting the development of this promising material. This work focuses on the stimulated growth characteristics and microstructural regulation methods of the waxy layers. It is found that the wax layers exhibit a corresponding behavior of changing their surface micromorphology under force, heat, solvents, and other stimuli during the self-growth process, and as a result of which, various types of fine surface microstructures such as grids, rings, stripes, pattern copying, and printing can be self-built on their surfaces. The composition of the surface autocrine wax layer changes with the autocrine time, and this finding may be useful for the separation and purification of alkane mixtures. In addition, the surface wax layer possesses the ability to self-heal and strengthen itself at the damage site after being stimulated by injury, similar to the damage-response behavior of a bark surface. Such multi-stimulus response behavior described here provides a platform for the discovery of more functional materials and microstructural self-construction techniques and can also serve as a basis for their applications.
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Zinc rich epoxy (ZRE) coatings can provide sacrificial anode protection for metal substrate. Electrically conductive fillers can be added into ZRE coatings to create electroconductive ...network and improve the utilization of zinc particles. Inspired by the structure of reinforced concrete, in this work, carbon fibers with a length of 2 mm, 5 mm, and 10 mm were used as electrically conductive fillers to drive more zinc particle into electrically conductive paths and to provide coatings with better mechanical properties. Without agglomeration, ZRE-10 can achieve an efficient protection for copper substrate up to 50 days in 3.5 wt% NaCl solution, much longer than that of ZRE coating. Moreover, the fraction of water absorbed by ZRE-10 is 14%, which for ZRE is 20%, and the adhesion strength of ZRE-10 increased by 65% compared with that of ZRE. All tests in this work can prove a remarkably enhanced anticorrosion performance and mechanical properties of ZRE coatings achieved by addition of longer carbon fibers.
Anti-icing gels inhibit ice formation and accretion; however, current iterations face prevalent drawbacks such as poor strength, weak substrate adhesion, and limited anti-icing properties. Herein, we ...propose a novel approach to address these challenges by developing a thermomechanical robust polyionic elastomer (PIE) with enhanced anti-icing properties. The PIE surface exhibits an icing delay time up to 5400 s and remains frost-free after exposure to −10 °C for 3.5 h, attributed to the inhibitory effect on ice formation by ions from ILs and the polyelectrolyte network. Moreover, the PIE exhibits remarkable anti-icing durability, with ice adhesion strengths below 35 kPa after undergoing 30 icing/deicing cycle tests at −20 °C. Following sandpaper abrasion (300 cycles), scratching, and heat treatment (100 °C, 16 h), the adhesion strength remains ca. 20 kPa, highlighting its resilience under various thermal and mechanical conditions. This exceptional durability is attributed to the low volatility of the IL and the robust ionic interactions within the PIE network. Furthermore, the PIE demonstrates favorable self-healing properties and strong substrate adhesion in both low-temperature and ambient environments, facilitated by the abundance of hydrogen bonds and electrostatic forces within PIE. This work presents an innovative approach to developing high-performance, durable, and robust anti-icing materials with potential implications across various fields.
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Marine biofouling is a generic term for animas plants and micro-organisms that grow on the surface of all installations on the hull and in the sea. Currently, the incorporation of ...antifouling agents into organic coatings is the most economical and effective means to combat marine biofouling. UiO-66-NH2 based metal–organic frameworks are a new type of nanocontainers for encapsulation and release of molecules due to their porous structure, large specific surface area, high crystallinity, and tunable chemical functionality. In this study, carboxylated benzisothiazolinones (BIT-COOH) encapsulated metal–organic frame-work (UiO-66-NH2) was prepared as release vehicle for stable release of antifoulants. The antibacterial activities of the prepared BIT-COOH, UIO-66-NH2 without and with BIT-COOH, against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria were determined by the zone of inhibition test (ZOI), minimum inhibitory concentration (MIC) and plate colony count. The results show that UiO-66-NH2-loaded BIT-COOH (UiO-66-NH2@BIT-COOH) containing 0.1 mg/mL has a bactericidal effect close to 100 % after 6 h. The antifouling coating prepared with UiO-66-NH2@BIT-COOH mixed with acrylic resin had excellent anti-bacterial, bacterial seaweed adhesion at lower levels (4 wt%). The study is a guide to the development of novel long-lasting antifouling coatings.
