in the production of polypropylene, the world's second-most widely produced synthetic plastic. The global demand for polypropylene has been rising continuously and its annual growth rate is expected to be 4-5% before 2020, resulting in increasing need for polymer-grade (>99.5%) propylene. [3] Nevertheless, the production of highly pure propylene represents a challenging and complicated process, which involves the separation of propylene from a propane/propylene mixture. Propane/ propylene mixtures are typically obtained by steam cracking of naphtha or during fluid catalytic cracking of gas oils in refineries, with a propylene purity of 50-60% for the former and 80-87% for the latter. Conventional separation of propane and propylene relies on cryogenic distillation, which is carried out at about 243 K and 0.3 MPa in a column containing over 100 trays. [4] Undoubtedly, this heat-driven process is highly energy-intensive.To lower the energy and operational cost and to suppress the carbon emissions associated with the propylene purification process through cryogenic distillation, several alternative technologies have been proposed and among them adsorptive separation, such as pressure/temperature swing adsorption, Adsorptive separation of olefin/paraffin mixtures by porous solids can greatly reduce the energy consumption associated with the currently employed cryogenic distillation technique. Here, the complete separation of propane and propylene by a designer microporous metal-organic framework material is reported. The compound, Y 6 (OH) 8 (abtc) 3 (H 2 O) 6 (DMA) 2 (Y-abtc, abtc = 3,3′,5,5′-azobenzene-tetracarboxylates; DMA = dimethylammonium), is rationally designed through topology-guided replacement of inorganic building units. Y-abtc is both thermally and hydrothermally robust, and possesses optimal pore window size for propane/propylene separation. It adsorbs propylene with fast kinetics under ambient temperature and pressure, but fully excludes propane, as a result of selective size exclusion. Multicomponent column breakthrough experiments confirm that polymer-grade propylene (99.5%) can be obtained by this process, demonstrating its true potential as an alternative sorbent for efficient separation of propane/propylene mixtures.

Fluorescence-based detection is one of the most efficient and cost-effective methods for detecting hazardous, aqueous Hg 2+ . We designed a fluorescent porous organic polymer (TPA-POP-TSC), with a "fluorophore" backbone and a thiosemicarbazide "receptor" for Hg 2+ -targeted sensing. Nanometer-sized TPA-POP-TSC spheres (nanoPOP) were synthesized under mini-emulsion conditions and showed excellent solution processability and dispersity in aqueous solution. The nanoPOP sensor exhibits exceptional sensitivity (K sv = 1.01 × 10 6 M −1 ) and outstanding selectivity for Hg 2+ over other ions with rapid response and full recyclability. Furthermore, the nanoPOP material can be easily coated onto a paper substrate to afford naked eye-based Hg 2+detecting test strips that are convenient, inexpensive, fast, highly sensitive, and reusable. Our design takes advantage of the efficient and selective capture of Hg 2+ by thiosemicarbazides (binding energy = −29.84 kJ mol −1 ), which facilitates electron transfer from fluorophore to bound receptor, quenching the sensor's fluorescence.

The separation of n‐alkanes from their branched isomers is vitally important to improve octane rating of gasoline. To facilitate mass transfer, adsorptive separation is usually operated under high temperatures in industry, which require considerable energy. Herein, we present a kind of dynamic pillar‐layered MOF that exhibits self‐adjustable structure and pore space, a behavior induced by guest molecules. A combination of the flexibility of the framework with the commensurate adsorption for n‐hexane results in exceptional performance in separating hexane isomers. More significantly, lower temperature prompts the guest molecules to open the dynamic pores, which may provide a new perspective for optimized separation performance at lower temperatures with less energy consumption.

We have synthesized a stable luminescent metal–organic framework (LMOF) through modification of an established Zr-based structure. The three-dimensional porous network of LMOF-321 represents a step forward in the development of robust, dual-ligand Zr-MOFs. This material is based on Zr6-nodes, which underlie chemically and thermally stable frameworks. LMOF-321 exhibits notable durability in diverse types of water samples (deionized, acidic/basic, seawater). The porosity, luminescence, and specific functionality from LMOF-321 establishes itself as a fluorescent chemical sensor and adsorbent for aqueous analytes. Studies have been implemented to analyze interactions of LMOF-321 with Li+ and other metals commonly found in water. The fluorescence intensity from LMOF-321 is responsive to Li+ at a parts per billion level (3.3 ppb) and demonstrates high selectivity for Li+ over other light metals, with detection ratios of 6.2, 14.3, and 44.9 for Li+/Na+, Li+/Ca2+, and Li+/Mg2+, respectively. These performances were maintained in ion-doped deionized and seawater samples, highlighting the potential of LMOF-321 for field applications. The Li+ K SV value for LMOF-321 (6549 M–1) sets the standard for LMOF sensors. ICP-OES reveals the selective adsorption of Li+ over other light metals, consistent with fluorescence measurements. LMOF-321 has a maximum uptake capacity of 12.18 mg/g, on par with lithium extraction materials. The adsorption data was fitted using Langmuir adsorption model with a high correlation factor (>0.999). XPS and FTIR studies provide insight to help understand the interaction mechanism between Li+ and LMOF-321, focusing on the bis­(sulfonyl)­imide functionality in the pillaring coligand. No other MOFs have been utilized for both the detection and extraction of Li+, rendering this work one step further toward more efficient harvesting procedures.

The separation of n‐alkanes from their branched isomers is vitally important to improve octane rating of gasoline. To facilitate mass transfer, adsorptive separation is usually operated under high temperatures in industry, which require considerable energy. Herein, we present a kind of dynamic pillar‐layered MOF that exhibits self‐adjustable structure and pore space, a behavior induced by guest molecules. A combination of the flexibility of the framework with the commensurate adsorption for n‐hexane results in exceptional performance in separating hexane isomers. More significantly, lower temperature prompts the guest molecules to open the dynamic pores, which may provide a new perspective for optimized separation performance at lower temperatures with less energy consumption.