Separation of light hydrocarbon isomers is always an important and challenging task in the petrochemical industry due to their similar physicochemical properties. This paper presents the absorption-adsorption hybrid method to separate pentane isomers using a flowable zeolitic imidazolate framework-8 (ZIF-8) slurry prepared with N, N′-Dimethylpropylene urea (DMPU) and water. Firstly, the single-component kinetic sorption profiles for n-pentane and iso-pentane in the slurry were measured. It appears significant sorption kinetic differences between the pentane isomers in ZIF-8/DMPU-water slurry. Subsequently, the separation performances for n/iso-pentane gas mixtures were studied systematically. The results show that the selectivity for pentane isomers using ZIF-8/water slurry is extremely high (1877 specifically), and the selectivity decreases gradually when the DMPU content in the solvent increases, while conversely the sorption speed increases rapidly. The selectivity as a function of time was described to graphically characterize the kinetic-based separation for pentane isomers. With excellent behavior in selectivity, sorption speed, sorption capacity (1.10 mol/L for n-pentane in ZIF-8/DMPU slurry), and renewability, this absorption-adsorption hybrid method is of great potential in the separation of pentane isomers.
To accelerate the commercial application of organic–inorganic hybrid perovskite solar cells (PSCs), it is necessary to develop simple and low-cost methods to prepare pinhole-free large-area perovskite films with high quality. A one-step blade coating method is regarded as a scalable technique. It is demonstrated that with the addition of N,N′-dimethylpropyleneurea (DMPU) in an FA-dominated perovskite precursor, a large-area high-quality perovskite film can be obtained by blade coating, achieving improved photovoltaic performance, thermal stability, and storage stability. It is found that the strong interaction between DMPU and Pb2+ ions is beneficial to delay the nucleation crystallization process, increase the size of crystal grains, and improve the crystallinity of the perovskite film. Planar n–i–p solar cells introducing DMPU exhibit power conversion efficiencies of 20.20% for 0.16 cm2 devices and 17.71% for 5 × 5 cm2 modules with an aperture area of 10 cm2. In addition, the devices without encapsulation placed at 50 °C for 500 h and with a relative humidity of 20 ± 5% for 1000 h still maintain efficiencies above 80 and 90%, respectively, showing outstanding stability.
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