Two-Dimensional Metal-Organic Frameworks/Epoxy Composite Coatings with Superior O/HO Resistance for Anticorrosion Applications.

Corrosion protection technology plays a crucial role in preserving infrastructure, ensuring safety and reliability, and promoting long-term sustainability. In this study, we combined experiments and various analyses to investigate the mechanism of corrosion occurring on the epoxy-based anticorrosive coating containing the additive of two-dimensional (2D) and water-stable zirconium-based metalorganic frameworks (Zr-MOFs). By using benzoic acid as the modulator for the growth of the MOF, a 2D MOF constructed from hexazirconium clusters and BTB linkers (BTB = 1,3,5-tri(4-carboxyphenyl)benzene) with coordinated benzoate (BA-ZrBTB) can be synthesized.

Immobilization of europium and terbium ions with tunable ratios on a dispersible two-dimensional metal-organic framework for ratiometric photoluminescence detection of DO.

A two-dimensional zirconium-based metal-organic framework (2D Zr-MOF), ZrBTB (BTB = 1,3,5-tri(4-carboxyphenyl)benzene), is used as a platform to simultaneously immobilize terbium ions and europium ions with tunable ratios on its hexa-zirconium nodes by a post-synthetic modification. The crystallinity, morphology, porosity and photoluminescence (PL) properties of the obtained 2D Zr-MOFs with various europium-to-terbium ratios are investigated. With the energy transfer from the excited BTB linker to the installed terbium ions and the energy transfer from terbium ions to europium ions, a low loading of immobilized europium ions and a high loading of surrounding terbium ions in the 2D Zr-MOF result in the optimal PL emission intensities of europium; this phenomenon is not observable for the physical mixture of both terbium-installed ZrBTB and europium-installed ZrBTB.

Two-dimensional metal-organic framework for post-synthetic immobilization of graphene quantum dots for photoluminescent sensing.

Immobilization of graphene quantum dots (GQDs) on a solid support is crucial to prevent GQDs from aggregation in the form of solid powder and facilitate the separation and recycling of GQDs after use. Herein, spatially dispersed GQDs are post-synthetically coordinated within a two-dimensional (2D) and water-stable zirconium-based metal-organic framework (MOF). Unlike pristine GQDs, the obtained GQDs immobilized on 2D MOF sheets show photoluminescence in both suspension and dry powder.

[Scale Effects of Landscape Pattern on Water Quality in Dongjiang River Source Watershed].

Based on water quality monitoring data and land use data, Dongjiang River source watershed water quality variation characteristics from 2017 to 2019 and the relationships between the landscape pattern of the Dongjiang River source watershed and water quality were analyzed using spatial analysis, correlation analysis, and redundancy analysis. The results showed that:① the water quality of the Dongjiang River source watershed improved overall, but the total nitrogen pollution was still severe. As of 2019, the annual average concentration of total nitrogen in all sampling points exceeded the type Ⅲ water quality standard.

A Quantitative Study of Micro and Macro Mechanical Parameters Based on the PFC Flat-Joint Model.

The flat-joint model, which constructs round particles as polygons, can suppress rotation after breakage between particles and simulate more larger compression and tension ratios than the linear parallel-bond model. The flat-joint contact model was chosen for this study to calibrate the rock for 3D experiments. In the unit experiments, the triaxial unit was loaded with flexible boundaries, and the influence of each microscopic parameter on the significance magnitude of the macroscopic parameters (modulus of elasticity , Poisson's ratio , uniaxial compressive strength , crack initiation strength , internal friction angle and uniaxial tensile strength ) was analysed by ANOVA (Analysis of Variance) in an orthogonal experimental design.

Metal-Organic Framework-Derived Electrocatalysts Competent for the Conversion of Acrylonitrile to Adiponitrile.

Electrochemical conversion of acrylonitrile (AN) to produce adiponitrile (ADN), the raw material for the production of Nylon 66, has become a crucial process owing to the increasing market demand of Nylon 66. Although the metallic Pb or Cd electrodes are commonly used for this reaction, the use of electrocatalysts or electrodes modified with catalysts has been barely investigated. In this study, nanoporous and electrically conductive metal-organic framework (MOF)-derived materials composed of Pb, PbO, and carbon are synthesized by carbonizing a Pb-based MOF through thermal treatments, and these MOF-derived materials are served as electrocatalysts for the electrosynthesis of ADN.

Probing the electronic and ionic transport in topologically distinct redox-active metal-organic frameworks in aqueous electrolytes.

Three topologically distinct zirconium-based metal-organic frameworks (Zr-MOFs) constructed from redox-innocent linkers, MOF-808, defective UiO-66, and CAU-24, are synthesized, and the spatially dispersed redox-active manganese sites are post-synthetically immobilized on the hexa-zirconium nodes of these Zr-MOFs. The crystallinity, morphology, porosity, manganese loading, and bulk electrical conductivity of each material are studied. The redox-hopping-based electrochemical reaction between the installed Mn(III) and Mn(IV) occurring within the thin films of these MOFs in aqueous electrolytes is investigated, in the presence of various concentrations of NaSO in the electrolytes.

Corrosion Performance of Nano-TiO-Modified Concrete under a Dry-Wet Sulfate Environment.

This study compared the effects of the sulfate dry-wet cycle on the properties of ordinary concrete and nano-TiO-modified concrete, including the mass loss rate, ultrasonic wave velocity, compressive strength, and XRD characteristics. In addition, a series of compression simulations carried out using the PFC2D software are also presented for comparison. The results show the following: (1) with an increase in dry-wet cycles, the damage to the concrete gradually increased, and adding nano-TiO into ordinary concrete can improve the material's sulfate resistance; (2) after 50 sulfate dry-wet cycles, the mass loss rate of ordinary concrete was -3.