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Abstract Fluoro‐ and chlorofluorocabons (FC/CFCs) are important refrigerants, solvents, and fluoropolymers in industry while being toxic and carrying high global warming potential. Detection and reclamation of FC/CFCs based on adsorption technology with highly selective adsorbents is important to labor safety and environmental protection. Herein, the study reports an integrated method to combine capture, separation, enrichment, and analysis of representative FC/CFCs (chlorodifluoromethane(R22) and 1,1,1,2‐tetrafluoroethane (R134a)) by using the highly stable and porous Zr‐MOF, DUT‐67. Gas adsorption and breakthrough experiments demonstrate that DUT‐67 has high R22/R134a uptake (124/116 cm3 g−1) and excellent R22/R134a/CO2 separation performance (IAST selectivities of R22/CO2 and R134a/CO2 ranging from 51.4 to 33.3, and 31.1 to 25.8), even in rather low concentration and humid conditions. A semi‐quantitative analysis protocol is set up to analyze the low concentrations of R22/R134a based on the high selective R22/R134a adsorption ability, fast adsorption kinetics, water‐resistant utility, facile regeneration, and excellent recyclability of DUT‐67. In situ single‐crystal X‐ray diffraction, theoretical calculations, and in situ diffuse reflectance infrared Fourier transform spectra have been employed to understand the adsorption mechanism. This work may provide a potential adsorbent for purge and trap technique under room temperature, thus promoting the application of MOFs for VOCs sampling and quantitative analysis.

Metal–organic frameworks with highly ordered porosity have been studied extensively. In this paper, the effect of framework (pore) disorder on the gas sorption of azole-based isoreticular Cu(II) MOFs with rtl topology and characteristic 1D tubular pore channels is investigated for the first time. In contrast to other isoreticular rtl metal–organic frameworks, the Cu(II) metal–organic framework based on 5-(1H-imidazol-1-yl)isophthalate acid has a crystallographically identifiable disordered framework without open N-donor sites. The framework provides a unique example for investigating the effect of pore disorder on gas sorption that can be systematically evaluated. It exhibits remarkable temperature-dependent hysteretic CO2 sorption up to room temperature, and shows selectivity of CO2 over H2, CH4 and N2 at ambient temperature. The unique property of the framework is its disordered structure featuring distorted 1D tubular channels and DMF-guest-remediated defects. The results imply that structural disorder (defects) may play an important role in the modification of the performance of the material.

Fast and sensitive detection of water molecules in organic solvents and gases remains an important challenge. Here, Pan and co-workers design a metal-organic framework capable of ultrafast and reversible water sensing by photoluminescence switching via an excited state intramolecular proton transfer mechanism.

The natural gas upgrading applications involving CH4 purification and concurrent C3H8/n-C4H10 recovery are of great importance yet highly challenging for safe and efficient subsequent manufacturing of downstream commodities due to their similar physicochemical properties and ultra-low concentration. Herein, a robust Zr-MOF, LIFM-233, with optimized pore size/volume/surface ascribed to the introduction of π-electron-rich naphthalene moieties, has been constructed with 6-(4-carboxyphenyl)-2-naphthalenecarboxylate (L) and Zr6 cluster for natural gas upgrading. Based on the high pore volume, optimized pore size, and π-electron-rich pore surface, LIFM-233 presents high C3H8/n-C4H10 uptake capacity (229.3/262.8 cm³ g−1 at 298 K and 1 bar) and good C2–C4/CH4 selective adsorption performance, confirmed by single-component adsorption and dynamic breakthrough experiments. Additionally, high purity of C3H8 (>91.6%) or n-C4H10 (>94.0%) can be afforded through a single regeneration curve. The underlying gas-binding mechanism has been well established by theoretical simulations, which reveal that C–H⋯O hydrogen bonds (HBs) between gas and Zr–O clusters, and C–H⋯π interactions between gas and aromatic rings, collaboratively play pivotal roles in the selective separation of C2–C4 hydrocarbons from CH4, thus demonstrating the importance of the introduction of an appropriate aromatic system. [ABSTRACT FROM AUTHOR]

The hot deformation behavior of TB8 titanium alloy with a lamellar α structure in the α+β dulex phase region was investigated. The results show that at the strain rate of 1 s-1, a continuous flow softening phenomenon is observed in the curve of the samples deformed at 650 ℃, while a discontinuous yield phenomenon is visual in the curve of the samples when the deformation temperature is higher than 650 ℃. The discontinuous yield phenomenon is gradually disappeared with increasing deformation temperature and strain rate. When the strain rate is 0.001 s-1 and the deformation temperature is 750 ℃ as well as 800 ℃, typical characteristics of dynamic recrystallization is presented in the curve of the samples. The relationship among peak stress σp temperature T and strain rate ε · and is characterized by Arrhenius-type constitutive equation. The equation between the material constants (α, Q, n and lnA) and strain is constructed. The effect of strain on the material constants (α, Q, n and lnA) of the Arrhenius-type constitutive equation is analyzed. The value of α is increased with true strain, while the values of Q, n and lnA are gradually decreased. The correlation coefficient (R2) and the AARE value between the experimental and the predicted stress are 0.945 and 9.08%, respectively. This indicates that the strain-compensates Arrhenius type constitutive equation can better predict the flow stress value under different deformation conditions for the TB8 titanium alloy with a lamellar α structure deformed in the α+β dulex phase region.