Smart materials with unique surface wetting properties have attracted considerable interest, particularly for oil/water separation, where oil can cause severe environmental damage. Despite 2 the considerable progress made in the past decade, critical challenges remain in scaling up, as smart materials are either expensive to fabricate or involve complicated, energy-intensive, and/or time-consuming production processes. In this work, an ultra-facile approach to fabricate hierarchical Zeolitic Imidazolate Framework-L (ZIF-L) mesh films with switchable superwettability for efficient oil/water separation was reported for the first time. A thick, continuous layer of well-intergrown ZIF-L nanoplates with an average aspect ratio of ~25 was successfully synthesized on various stainless steel (SS) meshes at ambient conditions. The ZIF-L mesh films exhibited extraordinary in-air superamphiphilic, underwater superoleophobic and underoil superhydrophobic properties, and showed outstanding performance in solely-gravitydriven oil/water mixture separation. Interestingly, a prewetting-induced switchable permeation function was found for the hierarchical ZIF-L surface, truly achieving "oil-blocking" and "water-blocking" separation. The ZIF-L mesh films demonstrated superior cyclic separation performance for a variety of oil/water mixtures with separation efficiencies above 99.99% and satisfactory chemical and mechanical stabilities even in harsh conditions. Their rapid and energy-efficient fabrication is therefore highly promising for cost-efficient and large-scale production for widespread applications in oil/water separation.

The exponential rise in lithium demand over the last decade, as one of the largest sources for energy storage in terms of lithium-ion batteries (LIBs), has posed a great threat to the existing lithium supply and demand balance. The current methodologies available for lithium extraction, separation and recovery, both from primary (brines/seawater) and secondary (LIBs) sources, suffer not only at the hands of excessive use of chemicals but complicated, time-consuming and environmentally detrimental design procedures. Researchers across the world are working to review and update the available technologies for lithium harvesting in terms of their economic and feasibility analysis. Following its excessive consumption of sustainable energy resources, its demand has risen sharply and therefore requires urgent attention. In this paper, different available methodologies for lithium extraction and recycling from the most abundant primary and secondary lithium resources have been reviewed and compared. This review also includes the prospects of using membrane technology as a promising replacement for conventional methods.

No abstract

No abstract

A novel continuous fluid circulation system was designed and employed for the impregnation seeding and fabrication of zeolitic imidazolate framework (ZIF) crystals on the internal surface of polymeric hollow fibre...

Morphological tailoring of crystalline nanomaterials such as zeolitic imidazolate frameworks (ZIFs) is essential for various applications, including oil-water separations, molecular sieving, and antibacterial applications. However, precise control of the morphology of these crystals is challenging. Herein, the morphological evolution map of ZIF-L to ZIF-8 nanocrystals on porous polymer supports was constructed in terms of ethanol content and processing temperature variation. Subsequently, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analyses demonstrated that an increase in the temperature in low ethanol content led to the formation of ZIF-L nanocrystals with decreased lateral size and increased crystal thickness. Comparatively, increased ethanol content typically increases crystal thickness with a greater degree of crystal intergrowth. However, an increase in both parameters exhibited a preferential formation of its three-dimensional (3D) structural analog, ZIF-8, and consequently resulted in a ZIF-L/ZIF-8 mixed phase at midrange temperatures (50–60 °C) and ethanol content (10 v/v%). The mixed phase demonstrated the stacking of ZIF nanosheets, with the morphology change significantly impacting the properties of the ZIF nanocrystals. As one example, the antibacterial performance of the as-prepared materials of different morphologies was analyzed to investigate the morphological impact on antibacterial efficiency. It was found that crystals with reduced crystal size and increased surface area resulted in improved antibacterial performance. Meanwhile, the nanostructured ZIF coating’s hydrophilicity and hydrostability were also enhanced with increased ethanol content and elevated temperatures. Overall, we reported a very useful method to conveniently control the morphology of ZIF nanocrystals for improved applications.

Integrated metal–organic frameworks (MOFs) with graphene oxide (GO) have aroused huge interest in recent years due to their unique properties and excellent performance compared to MOFs or GO alone. While a lot of attention has been focused on the synthesis methodologies and the performance analysis of the composite materials in recent years, the fundamental formation/crystallization mechanism(s) is (are) still not fully understood. Ascribed to the distinctive structural and functional properties of GO, the nucleation and crystallization process of MOFs could be altered/promoted, forming MOF/GO composite materials with different nanostructures. Furthermore, the MOF’s parental structure could also influence how the GO and MOF bond together. Thus, this short review attempted to provide critical and indepth discussions of recent research results with a particular focus on the factors that influence the directional growth of parent MOFs in the presence of graphene oxide. Due to the unique structure and enhanced properties, the derived MOF/GO composites have a wide range of applications including gas separation, electrochemistry, and photocatalysis. We hope this review will be of interest to researchers working on MOF design, crystal structure control (e.g., orientation), and composite materials development.

No abstract