Mixed-Matrix Membranes (MMMs) combining the benefits of both polymeric and inorganic materials have become a focus for the next-generation gas separation membranes. In this review, major challenges surrounding MMMs and the strategies to tackle these challenges are given in detail. The selection criteria of polymeric and inorganic materials are discussed in terms of their physical and chemical compatibility as well as large scale fabrication issues. Major models for separation performance prediction of MMMs are reviewed in terms of their interrelations and limitations. A discussion is provided regarding the future direction of MMMs.

Stable emission in glass: Lead halide perovskites can exhibit bright, narrow band photoluminescence but have stability issues related to formation of inactive phases and the loss of lead ions. Hou et al . show that the black, photoactive phase of cesium lead iodide can be stabilized by forming a composite with a glassy phase of a metal-organic framework through liquid-phase sintering. The photoluminescence is at least two orders of magnitude greater than that of the pure perovskite. The glass stabilizes the perovskite under high laser excitation, and about 80% of the photoluminescence was maintained after 10,000 hours of water immersion. —PDS

Pebax-based composite hollow fibre membranes are promising candidates for industrial gas separation, but their application is limited by the inherent separation performance of the polymeric materials and the poor operational stability especially under elevated pressures. The incorporation of metal–organic frameworks (MOFs) has been extensively investigated as a potential solution to these problems. However, the major challenges are to control the microvoids in the interfacial region and to improve the effective MOF loading within the selective layer. In this work, we applied a zirconium-based rigid MOF (UiO-66) to fabricate a nanocomposite hollow fibre membrane, and (–COOH) and (–NH₂) modified UiO-66 were applied to investigate the effect of surface functionalization. Up to 80 wt% UiO-66 was incorporated into the thin Pebax selective layer, and both improved CO₂ permeance and selectivity were obtained simultaneously with the (–NH) functionalized UiO-66. In addition, the presence of UiO-66 in Pebax significantly improved the membrane's operational stability under high pressure.