Mixed-matrix membranes (MMMs) for CO 2 /N 2 separation were prepared by incorporating nickel-substituted ZIF-8 (Zn/Ni-ZIF-8) into a polyether-block-amide (PEBA2533) polymer, in which the Zn and Ni ions in Zn/Ni-ZIF-8 have different affinities for CO 2 based on π-complexation; these MMMs exhibited exceptional molecular sieving properties compared to ZIF-8-PEBA MMMs. Scanning electron microscopy revealed that Zn/Ni-ZIF-8 nanoparticles were small and uniformly distributed within the PEBA, and attenuated total reflectance Fourier-transform infrared spectroscopy revealed good interfacial compatibility between the Zn/Ni-ZIF-8 and PEBA; consequently these MMMs exhibited excellent mechanical properties . The 10% Zn/Ni-ZIF-8-PEBA MMM showed a high CO 2 permeability of 321 Barrer, and a CO 2 /N 2 selectivity of 42.8 at 2 bar; these values were much higher than those of the 10% ZIF-8-PEBA MMM (266 Barrer and 33.8, respectively). We assume that different metal-ion affinities towards CO 2 resulted in the asymmetric adsorption/desorption behaviour of these MMMs, which led to a significantly higher permselectivity for the Zn/Ni-ZIF-8-PEBA MMM. The MMM loaded with 10% Zn/Ni-ZIF-8 exhibited long-term CO 2 -separation-performance stability under mixed-gas conditions, with a CO 2 permeability of 282 Barrer and a CO 2 /N 2 selectivity of 42.7. Moreover, the permselectivity of the 10% Zn/Ni-ZIF-8-PEBA MMM under pure-gas condition surpassed Robeson's upper bound reported in 2008.
Wheat gliadin is thought to be the main cause of wheat allergy leading to celiac disease. In this study, we reported an electrochemical immunosensor based on AuNPs/Zn/Ni-ZIF-8-800@graphene for simple, efficient, and sensitive detection of gliadin. A monoclonal antibody against gliadin were prepared by hybridoma technique. Zn/Ni-ZIF-8-800 with high stability was prepared by using zinc–nickel bimetallic organic framework MOFs, and graphene and gold nanoparticles with large surface area and excellent conductivity were introduced. Chitosan was used as a binder to fixed the composite on the surface of glassy carbon electrode. The fabricated materials and the corresponding sensors were comprehensively characterized by X-ray diffractometer, scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and cyclic voltammetry analyses. Under the optimal conditions, the linear range of the electrochemical immunosensor was 0.1–100 μg mL −1 , and the detection limit was 0.950 μg mL −1 . In addition, the fabricated sensor exhibited high selectivity and long-term stability. The recovery test showed that the prepared sensor was suitable for the detection of gliadin in real food and feed, exhibiting great promising of the developed sensor in practical application. Graphical abstract
危险品化学品经营许可证（带存储）