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The pervaporation membrane technology integrated with catalytic function improves the conversion of esterification reactions by integrating reaction and separation processes in a single step. Optimizing the structure of the catalytic layer of the pervaporation membrane can effectively reinforce its enhancement effect on the esterification reaction. Here, a porous catalytic layer with high catalytic activity and low mass transfer resistance was successfully developed by the immersion phase inversion. The sulfonated poly­(vinyl alcohol) (SPVA) catalytic layer prepared by cross-linking poly­(vinyl alcohol) (PVA) with 5-sulfosalicylic acid (SSA) was coated on a graphitic carbon nitride-sodium alginate (g-C3N4-SA) membrane with polyacrylonitrile (PAN) as the support. The prepared pervaporation membranes with a porous catalytic layer were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The membrane catalytic performance was evaluated in the esterification reaction of acetic acid with ethanol in a pervaporation catalytic membrane reactor (PVCMR). As a result, the acetic acid conversion was up to 98.4% in 12 h at 75 °C with 20% molar fraction of the catalyst. Compared with the batch reaction (BR) under the same operating conditions, the acetic acid conversion rate was greatly improved by 24.4%. After five runs, the membrane still maintained excellent stability. In addition, the resistance-in-series model was considered to analyze the mass transfer resistance of the membrane. The results indicated that the porous catalytic layer had a lower mass transfer resistance of 1.38 × 105 s·m–1, accounting for only 46.1% of the overall resistance, while the dense catalytic layer accounted for 66.9%. Therefore, the pervaporation membrane with a porous catalytic layer presented great ability for enhancing the esterification reaction of acetic acid with ethanol.

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Investigation on the static fatigue mechanism and effect of specimen thickness on the static fatigue lifetime in WC-Co cemented carbides The static fatigue mechanism and effect of specimen thickness on static fatigue lifetime for four WC-Co cemented carbides were studied with different binder contents and carbide grain sizes. Static fatigue tests under three-point bend loading were conducted on different sized specimens. The fracture surfaces of rupture specimens were examined by scanning electron microscopy to investigate the static fatigue micromechanisms. Experimental results show that microcracks nucleate from defects or inhomogeneities and the connection of microcracks produces a main crack. The main crack propagates rapidly, resulting in the fracture of specimens. The extension of static fatigue lifetime with the increase of specimen thickness is due to the decrease of plastic zone size near the crack tip and relevant energy change during the crack growth. The effect of specimen thickness on static fatigue lifetime is much greater for cemented carbides with larger WC grain size or higher cobalt content, which is attributed to operative toughening mechanisms.

In this study, the data on solid−liquid equilibrium of L-prolinamide were studied using the gravimetric method. The solubility of L-prolinamide was measured in ten pure solvents (tetrahydrofuran, n-heptane, n-propanol, acetone, acetonitrile, ethyl acetate, N,N-dimethylformamide, n-hexane, cyclohexane, and isopropanol) and three binary solvent mixtures(ethyl acetate + tetrahydrofuran, n-heptane + ethyl acetate, and n-hexane + acetone) in the temperature range of 278.15−323.15 K at atmospheric pressure. The experimental values showed that the solubility increased with the increase of temperature in all solvents. The solubility data in different pure solvents were fitted using the modified Apelblat model and the Buchowski−Ksiazaczak λh model. For the solubility data of three binary solvent mixtures, the modified Apelblat model, the combined nearly ideal binary solvent/Redlich−Kister (CNIBS/R−K) model, and the Jouyban−Acree model were used to fit. In all four models, the modified Apelblat model had a better correlation with the solubility of L-prolinamide weather in pure solvents or binary solvent mixtures. The experimental results showed that n-heptane and n-hexane could be used as antisolvents, which could be used in the purification process of L-prolinamide and guide the large-scale production of many drugs such as Alpelisib in industries.