The design and synthesis of solid sorbents for effective carbon dioxide adsorption are essential for practical applications regarding carbon emissions. Herein, we report the synthesis of composite materials consisting of amine-functionalized imidazolium-type poly(ionic liquid) (PIL) and metal organic frameworks (MOFs) through complexation of amino groups and metal ions. The carbon dioxide adsorption behavior of the synthesized composite materials was evaluated using the temperature-programmed desorption (TPD) technique. Benefiting from the large surface area of metal organic frameworks and high carbon dioxide diffusivity in ionic liquid moieties, the carbon dioxide adsorption capacity of the synthesized composite material reached 19.5 cm3·g−1, which is much higher than that of pristine metal organic frameworks (3.1 cm3·g−1) under carbon dioxide partial pressure of 0.2 bar at 25 °C. The results demonstrate that the combination of functionalized poly(ionic liquid) with metal organic frameworks can be a promising solid sorbent for carbon dioxide adsorption.

No abstract

No abstract

Effects of treatment modes of precipitates in the coprecipitation method on the resulting YAG nanopowders and ceramics are investigated. Three treatment modes for precipitates, namely, single water washing, water–ethanol washing, and water washing–ethanol immersion, are conducted to prepare the YAG nanopowders. The average particle size (∼62 nm) and distribution (mainly ranging from 30 to 110 nm) of the powders obtained by the three modes are similar. However, the dispersity of the three powders shows large differences. The nanopowder obtained via water washing–ethanol immersion possesses optimal dispersity without any agglomeration, whereas that obtained via single water washing comprises substantially hard agglomerations. The relative density, Vickers hardness, and optical in‐line transmittance of the ceramics prepared via water washing–ethanol immersion, respectively, reach 99.85%, 14.1 ± .4 GPa, and 77.8% at 1064‐nm wavelengths after spark plasma sintering. These results are markedly superior to those of the ceramics prepared using the two other modes (97.43%, 6.8 ± .7 GPa, and 17.2% at 1064‐nm wavelengths and 98.97%, 10.2 ± .5 GPa, and 47.8% at 1064‐nm wavelengths, correspondingly). Therefore, water washing–ethanol immersion is a sensible and advisable treatment mode of precipitates for preparing YAG nanopowder and ceramics via coprecipitation.

The paper proposed a method to improve the anti-oxidation performance of carbon fibers (CF) at high temperature environment by coating silicon dioxide (SiO2) and silicon carbide (SiC). The modified sol-gel method had been used to ensure the proper interface between fibers and coating. We used polydimethylsiloxane and ethyl orthosilicate to make stable emulsion to uniformly disperse SiC nanoparticles. The modified SiO2/SiC coating had been coated on CF successfully. Compared with the untreated CF, the coated fibers started to be oxidized around 900 °C and the residual weight was 57% at 1400 °C. The oxidation mechanism had been discussed. The structure of SiC/SiO2 coated CF had been characterized by scanning electron microscope and X-ray diffraction analysis. Thermal gravimetric analysis was used to test the anti-oxidation ability of CF with different coatings.

Uniform polyaniline (PANI) nanotubes were synthesized by a self-assembly method under relatively dilute hydrochloric acid (HCl) solution. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and UV-Vis-NIR spectroscopy were employed to characterize the morphology and molecular structure of the PANI products. SEM images show that the PANI nanotubes have uniform morphology and form compact coating on the substrate surface. For comparison, aggregated PANI was also synthesized by conventional polymerization method. The performance of the PANI products on carbon steel was studied using eletrochemical measurement and immersion corrosion experiment in 3.5 wt% NaCl aqueous solution. The corrosion potentials of carbon steel samples increase by 0.196 V and 0.060 V after coated with PANI nanotubes and aggregated PANI, respectively, and the corrosion currents density decrease by about 76.32% and 36.64%, respectively. The 6-day immersion experiment showed that the carbon steel samples coated by PANI nanotubes showed more excellent anticorrosion performance, because the more compact coating formed by PANI nanotubes may inhibit the corrosion process between the anodic and cathodic.

No abstract

No abstract