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Corrosion protection of steel bars in alkaline concrete environments poses a common challenge in marine engineering. One approach to mitigate steel bar corrosion is the addition of corrosion inhibitors to the concrete. In alkaline environments, the passivation of rebars occurs through anodic passivation coupled with the cathodic oxygen reduction reaction (ORR). The catalysis of ORR can expedite anode passivation. To investigate the corrosion inhibition of steel bars in alkaline environments, meso‐tetra(4‐carboxyphenyl)porphine (TCPP), known for its ORR catalytic properties, is selected. TCPP forms adsorption films on the surface of steel bars, facilitating the formation of passivation films. TCPP primarily adsorbs onto active sites on the surface of the passivation film, where lattice iron ions have leached. The adsorbed TCPP accelerates the formation of the passivation film through ORR catalysis, inhibiting the development of passivation film defects and enhancing the integrity and protection of the passivation film. The most significant effect is observed when the concentration of TCPP is 0.5 mmol/L. The physical adsorption of TCPP is primarily determined by the negative charge centers, namely the carboxyl group O and the pyrrole N. However, due to steric hindrance caused by the unrestricted rotation of the carboxyl benzene, the pyrrole N does not play a dominant role in chemical adsorption. Instead, the active site for chemical adsorption is the carboxyl group O. The adsorption process significantly reduces the diffusion coefficient of TCPP molecules, providing a robust and stable adsorption binding. Phthalocyanine molecules without carboxyl benzene groups adopt a planar structure, allowing them to form stable adsorption configurations on the iron surface through flat adsorption. This observation provides guidance for the design of novel metal phthalocyanine molecules. Specifically, the development of metal phthalocyanine molecules with modifying groups that are coplanar with the phthalocyanine ring and possess restricted rotation can achieve flat adsorption, improve coverage rate, and enhance adsorption configuration stability. [ABSTRACT FROM AUTHOR]

Three tetraphenylethene molecular cage-based polymers with blue, yellow, and red emission (TCPBs, TCPYs, and TCPRs) were synthesized through successive atom transfer radical polymerization (ATRP) reactions. In an aqueous solution, they exhibit aggregation-induced emission effects, resulting in blue, yellow, and red fluorescence respectively. These polymers can be combined to create stable white light emissive hybrid nanoparticles (TCPWs) through Freud resonance energy transfer (FRET) effects. The resulting TCPWs demonstrate excellent fluorescence stability and can serve as fluorescent probes for long-term intracellular imaging for as long as 10 passages (20 days), outperforming single fluorescence emissive probes. [ABSTRACT FROM AUTHOR]

Self-healing coatings, which possess the ability to repair damage and restore corrosion resistance without significant human intervention, have become a hot topic in corrosion protection research. In this paper, (±)-10-camphorsulfonic acid-doped polyaniline is synthesized and then combined with copolyurethane (copPU) to form the photothermal shape memory composite polymer (CSPA-copPU). An aggregation-induced emission agent, named N',2-bis[(E)-5-chloro-2-hydroxybenzylidene] hydrazine-1-carbohydrazide, is synthesized and applied to create a synergistic fluorescence system with a prepared chelation-enhanced fluorescence (CHEF) agent, named Rhodamine Benzimidazole. Under the CHEF behavior in response to Fe3+ and the fluorescence resonance energy transfer effect, the system exhibits a strong and sensitive fluorescence response to corrosion-generated Fe3+. Using electrospinning technology, CSPA-copPU@Fl fibers are prepared with CSPA-copPU as the shell and a mixture of fluorescent agents as the core solution and applied to create the composite coatings. The coatings effectively indicate damage in the form of fluorescence, providing guidance for infrared laser repair. CSPA facilitates the passivation of exposed steel. Under irradiation by an infrared laser, the surface temperature reaches the glass transition temperature of copPU and the epoxy binder. Through softening expansion and diffusion entanglement of molecular chains, scratches in the coatings are closed and repaired, and the corrosion resistance is restored to a level of intact coatings. [ABSTRACT FROM AUTHOR]

d–π overlap, which represents overlap between metal-d and graphene-π orbitals to facilitate electron transfer, has rarely been reported. Ni/PtNi-G2 exhibits exceptional performance in seawater hydrogen evolution due to the electron-rich surface on Pt resulting from enhanced d-π overlap and subsequent electron transfer from graphene and Ni to Pt. [ABSTRACT FROM AUTHOR]

Recently, functional molecules such as Polydopamine (PDA), Hyaluronic Acid (HA) and heparin have been widely studied in the field of surface modification of magnesium (Mg) alloy stents for better degradation behavior and biocompatibility, but their further application is limited by undesirable anticoagulant function, uncontrollable degradation and easy bleeding, respectively. Regarding to this consideration, a magnesium Fluoride/Polydopamine/Sulphonated hyaluronic acid (MgF 2 /PDA/S-HA) composite coating was successfully prepared by applying S-HA with sulfur content of 9.71 wt% on the surface of ZE21B alloy in this study. The results showed that the composite coating with a unique mesh structure not only inherited the anticoagulant effect of sulfonic acid group and the excellent cyto-compatibility of S-HA with high sulfur content, but also significantly improved the corrosion performance of ZE21B alloy. These results indicate a great application potential of the composite coating in the field of cardiovascular biomaterials. [ABSTRACT FROM AUTHOR]

A solvothermal method to prepare PtNi alloys that have differing morphologies is described. By adjusting the feed ratio of Pt and Ni precursors in this process, PtNi alloys with different compositions (Pt : Ni atomic ratio from 1 : 3 to 3 : 1) and morphologies (evolution from nanobranches to nanoparticles) are generated. The prepared Pt48Ni52 alloy, which has a composite morphology comprised of nanobranches and nanoparticles, exhibits superior activity and durability towards the hydrogen evolution reaction (HER) in seawater compared to those of commercial Pt/C catalyst and other PtNi alloys that have different compositions and morphologies. The excellent seawater HER performance of Pt48Ni52 is ascribed to its nanobranch/nanoparticle morphology that optimally facilitates electron accumulation on Pt, which enhances resistance to chloride corrosion in seawater. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) released by vascular endothelial cells (VECs), as a functional factor and signal pathway molecule, plays an important role in regulating vasodilation, inhibiting thrombosis, proliferation and inflammation. Therefore, numerous researches have reported the relationship between the NO level in VECs and the cardiovascular biomaterials' structure/functions. In recent years, biomedical magnesium (Mg) alloys have been widely studied and rapidly developed in the cardiovascular stent field for their biodegradable absorption property. However, influence of the Mg alloys' degradation products on VEC NO release is still unclear. In this work, Mg-Zn-Y-Nd, an Mg alloy widely applied on the biodegradable stent research, was investigated on the influence of the degradation time, the concentration and reaction time of degradation products on VEC NO release. The data showed that the degradation product concentration and the reaction time of degradation products had positive correlation with NO release, and the degradation time had negative correlation with NO release. All these influencing factors were controlled by the Mg alloy degradation behaviors. It was anticipated that it might make sense for the cardiovascular Mg alloy design aiming at VEC NO release and therapy. [ABSTRACT FROM AUTHOR]

In this study, the porous Mn2O3/TiO2 microspheres were prepared via a facile two-step hydrothermal method. Firstly, the Mn2O3 particles were obtained by the calcination of hydrothermal-synthesized MnCO3. Then the TiO2 layer was coated on the surface of the Mn2O3 particles by a hydrothermal-assisted liquid phase deposition (HA-LPD) method. The as-prepared samples were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and Brunauer-Emmett-Teller analyzer (BET), respectively. Moreover, the electrochemical performances of Mn2O3/TiO2 as an anode material in lithium ion batteries (LIBs) were also evaluated. The results indicated that, the specific capability of the Mn2O3/TiO2 composite material was about 452 mAh g−1 at the current density of 500 mA g−1 after 200 cycles, which was much higher than that of pristine Mn2O3 (313 mAh g−1). Meanwhile, the rate capacity of Mn2O3/TiO2 was 177 mAh g−1 at the current density of 4 A g−1, which was also higher than that of pure Mn2O3 (3 mAh g−1). Moreover, the Mn2O3/TiO2 composite material can still yield a specific capacity of 800 mAh g− 1 at the current density of 1 A g−1 after 1000 cycles. The enhanced electrochemical performances of Mn2O3/TiO2 composite material was mainly attributed to the synergistic effect between the Mn2O3 with high capacity and TiO2 with superior stability. [ABSTRACT FROM AUTHOR]