In this study, we synthesized and developed a novel desalination pervaporation (PV) composite membrane material. The matrix consisted of customized thermoplastic polyether block-amides (PEBA), and a hydrophilic interpenetrating chemical cross-linking structure was formed by the addition of polyethyleneimine (PEI) and ethylene glycol diglycidyl ether (EGDE) to make PEBA/PEI/EGDE/PTFE composite membranes. In order to improve the desalination performance, we investigated the effect of changing the ratio of PEI, EGDE and PEBA in the separation layer on the desalination efficiency of the composite PV membrane. Under the optimal conditions, the PEBA/PEI/EGDE/PTFE (M 4-1 ) composite membrane exhibited a water flux of 74.04 ± 0.79 kg/(m 2 ·h), and the salt rejection was maintained at 99.9 % in a 3.5 wt% NaCl solution at 70 °C. The M4-1 composite membrane also exhibited excellent acid-base stability, demonstrating salt removal rates after treatment in solutions at both pH = 2 and pH = 14, with removal exceeding 99.9 % in both cases after 360 h. Additionally, the measured water flux of the M 4-1 composite membrane was 39.84 ± 0.17 kg/(m 2 ·h) at 70 °C and a NaCl concentration of 20 wt%, highlighting its potential for treating high salinity solutions. This study presents a strategy of physical and chemical cross-linking of interpenetrating hydrophilic modified structures, which sheds light on the long-term stable operation of PV desalination membranes and lays the foundation for industrial applications in the concentration and purification of seawater or high salinity water under complex conditions.
Two-dimensional Co ultrathin metal–organic framework nanosheets (Co-UMOFNs) were synthesized and blended into poly (ether block amide) (PEBA) to prepare composite mixed matrix membranes on PVDF supports for the pervaporation of phenol aqueous solution. The membranes were characterized by XRD, ATR-IR, TGA, CA and SEM measurements. Effects of the Co-UMOFNs loading, feed temperature and feed concentration on phenol separation performance were investigated. The results showed that Co-UMOFNs have a two-dimensional layered morphology and have good compatibility with the PEBA. A “brick and mortar” architecture morphology was achieved after incorporating Co-UMOFNs into the PEBA membrane. The amorphous PE segments in the PEBA were turned into a crystalline structure, restricting the motion of PE segments. The filling of Co-UMOFNs slightly improved the thermal stability and hydrophobicity as well. With the increase of the Co-UMOFNs loading from 0% to 40%, the phenol separation factor increased from 27 to 45, and the total flux decreased from 1.2 kg m -2 h - 1 to 0.42 kg m -2 h - 1 , when separation of 1000 ppm phenol solution at 70 °C. The interlayer galleries induced by the Co-UMOFNs stacking increased the tortuosity, and the crystalline structure of the Co-UMOFNs-PEBA improved the energy barriers of water penetration. Therefore the water flux was inhibited and the phenol separation factor increased. Depression of water permeation can be another protocol to prepare high-performance organophilic pervaporation membranes.
危险品化学品经营许可证（带存储）