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Membranes with ultrahigh permeance and practical selectivity could greatly decrease the cost of difficult industrial gas separations, such as CH 4 /N 2 separation. Advanced membranes made from porous materials, such as metal-organic frameworks, can achieve a good gas separation performance, although they are typically formed on support layers or mixed with polymeric matrices, placing limitations on gas permeance. Here an amorphous glass foam, a gf ZIF-62, wherein a, g and f denote amorphous, glass and foam, respectively, was synthesized by a polymer-thermal-decomposition-assisted melting strategy, starting from a crystalline zeolitic imidazolate framework, ZIF-62. The thermal decomposition of incorporated low-molecular-weight polyethyleneimine evolves CO 2 , NH 3 and H 2 O gases, creating a large number and variety of pores. This greatly increases pore interconnectivity but maintains the crystalline ZIF-62 ultramicropores, allowing ultrahigh gas permeance and good selectivity. A self-supported circular a gf ZIF-62 with a thickness of 200-330 µm and area of 8.55 cm 2 was used for membrane separation. The membranes perform well, showing a CH 4 permeance of 30,000-50,000 gas permeance units, approximately two orders of magnitude higher than that of other reported membranes, with good CH 4 /N 2 selectivity (4-6)., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Several organic-inorganic hybrid materials from the metal-organic framework (MOF) family have been shown to form stable liquids at high temperatures. Quenching then results in the formation of melt-quenched MOF glasses that retain the three-dimensional coordination bonding of the crystalline phase. These hybrid glasses have intriguing properties and could find practical applications, yet the melt-quench phenomenon has so far remained limited to a few MOF structures. Here we turn to hybrid organic-inorganic perovskites-which occupy a prominent position within materials chemistry owing to their functional properties such as ion transport, photoconductivity, ferroelectricity and multiferroicity-and show that a series of dicyanamide-based hybrid organic-inorganic perovskites undergo melting. Our combined experimental-computational approach demonstrates that, on quenching, they form glasses that largely retain their solid-state inorganic-organic connectivity. The resulting materials show very low thermal conductivities (~0.2 W m -1 K -1 ), moderate electrical conductivities (10 -3 -10 -5  S m -1 ) and polymer-like thermomechanical properties., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Highly porous metal-organic frameworks (MOFs), which have undergone exciting developments over the past few decades, show promise for a wide range of applications. However, many studies indicate that they suffer from significant stability issues, especially with respect to their interactions with water, which severely limits their practical potential. Here we demonstrate how the presence of 'sacrificial' bonds in the coordination environment of its metal centres (referred to as hemilability) endows a dehydrated copper-based MOF with good hydrolytic stability. On exposure to water, in contrast to the indiscriminate breaking of coordination bonds that typically results in structure degradation, it is non-structural weak interactions between the MOF's copper paddlewheel clusters that are broken and the framework recovers its as-synthesized, hydrated structure. This MOF retained its structural integrity even after contact with water for one year, whereas HKUST-1, a compositionally similar material that lacks these sacrificial bonds, loses its crystallinity in less than a day under the same conditions.