Metal–organic frameworks (MOFs), a sub-group of porous crystalline materials, have been receiving increasing attention for gas separation and pervaporation because of their high thermal and chemical stability, narrow window sizes, as well as tuneable structural, physical, and chemical properties. In this review, we comprehensively discuss developments in the formation of continuous MOF membranes for gas separation and pervaporation. Additionally, the application performance of continuous MOF membranes in gas separation and pervaporation are analysed. Lastly, some perspectives for the future application of continuous MOF membranes for gas separation and pervaporation are given.
Three-bending test has been performed on the standard specimen and welding specimen with defect of low-alloy and high-strength steel in order to simulate the failure process of structural parts under loading, and the AE activities (number of hits) and stress-strain curve were measured during the whole loading process. The law of acoustic emission signals at different deformation stages has been investigated and the relation between AE characteristic parameters and the different deformation stages has been established. The typical AE waveforms such as friction noise, plastic deformation, welding microcrack initiation and propagation are obtained, which are analyzed by using spectrum characteristics analytical method. The spectrum characteristic parameters such as average frequency, peak frequency and frequency centroid, energy percentage of frequency spectrum part I and III of the typical AE defect signals are extracted, the distributing range of which are initially set. Study shows these five parameters have a closely relation with the nature of the AE signals, and based on these characteristics parameters different AE sources can be preliminary identified correctly. The study can provide some guidance to the practical application of AE acoustic emission technology in the industrial field.
Chitosan biopolymer membranes reinforced with channel-selective ZIF-8 nanofillers were developed and thoroughly characterized as separators for bioelectrochemical systems. This study explores the synergistic effect of incorporating ZIF-8 into a chitosan matrix to enhance membrane performance. Key properties including water retention, chemical and thermal stability, surface resistance, antifouling capacity, and ionic conductivity were evaluated and benchmarked against commercial Nafion-117 and nanofiltration (NF) membranes. The ZIF-8/chitosan composite membranes (ZIF-8/CS) demonstrated excellent water retention and structural stability under harsh conditions, along with significantly reduced surface resistance and effective rejection of organic contaminants and salts (NaCl, Na2SO4). Notably, the composite ZIF-8/CS membranes achieved an ionic conductivity of 0.099 S/cm, approaching the value of Nafion-117 (0.13 S/cm) and substantially surpassing that of the NF membrane (0.013 S/cm). These results indicate that ZIF-8-reinforced chitosan membranes present a promising, sustainable, and cost-effective alternative to traditional separators in bioelectrochemical applications.