Light olefins are the precursors of all modern-day plastics. Olefin is always mixed with paraffins in the time of production, and therefore it needs to be separated from paraffins to produce polymer-grade olefin. The state-of-the-art separation technique, cryogenic distillation, is highly expensive and hazardous. Adsorption could be a novel, sustainable, and inexpensive separation strategy, provided a suitable adsorbent can be designed. There are different types of mechanisms that were harnessed for the separation of olefins by adsorption, and in this review, we have focused our discussion on those mechanisms. These mechanisms include, (a) Affinity-based separation, like pi complexation and hydrogen bonding, (b) Separation based on pore size and shape, like size-exclusion and gate-opening effect, and (c) Non-equilibrium separation, like kinetic separation. In this review, we have elaborated each of the separation strategies from the fundamental level and explained their roles in the separation processes of different types of paraffins and olefins.

Thin-film composite mixed-matrix membranes (TFC-MMMs) have potential applications in practical gas separation processes because of their high permeance (gas flux) and gas selectivity. In this study, we fabricated a high-performance TFC-MMM based on a rubbery comb copolymer, i.e., poly(2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl] ethyl methacrylate)-co-poly(oxyethylene methacrylate) (PBE), and metal–organic framework MOF-808 nanoparticles. The rubbery copolymer penetrates through the pores of MOF-808, thereby tuning the pore size. In addition, the rubbery copolymer forms a defect-free interfacial morphology with polymer-infiltrated MOF-808 nanoparticles. Consequently, TFC-MMMs (thickness = 350 nm) can be successfully prepared even with a high loading of MOF-808. As polymer-infiltrated MOF is incorporated into the polymer matrix, the PBE/MOF-808 membrane exhibits a significantly higher CO₂ permeance (1069 GPU) and CO₂/N₂ selectivity (52.7) than that of the pristine PBE membrane (CO₂ permeance = 431 GPU and CO₂/N₂ selectivity = 36.2). Therefore, the approach considered in this study is suitable for fabricating high-performance thin-film composite membranes via polymer infiltration into MOF pores.

Efficient management of radionuclides that are released from various processes in the nuclear fuel cycle is of significant importance. Among these nuclides, radioactive iodine (mainly ¹²⁹I and ¹³¹I) is a major concern due to the risk it poses to the environment and to human health; thus, the development of materials that can capture and safely store radioactive iodine is crucial. Herein, a novel silver-thione-functionalized zeolitic imidazole framework (ZIF) was synthesized via postsynthetic modification and assessed for its iodine uptake capabilities alongside the parent ZIF-8 and intermediate materials. A solvent-assisted ligand exchange procedure was used to replace the 2-methylimidazole linkers in ZIF-8 with 2-mercaptoimidazole, forming intermediate compound ZIF-8 = S, which was reacted with AgNO₃ to yield the ZIF-8 = S-Ag⁺ composite for iodine uptake. Despite possessing the lowest BET surface area of the derivatives, the Ag-functionalized material demonstrated superior I₂ adsorption in terms of both maximum capacity (550 g I₂/mol) and rapid kinetics (50% loading achieved in 5 h, saturation in 50 h) compared to that of our pristine ZIF-8, which reached 450 g I₂/mol after 150 h and 50% loading in 25 h. This improvement is attributed to the presence of the Ag⁺ ions, which provide a strong chemical driving force to form a stable Ag-I species. The results of this study contribute to a broader understanding of the strategies that can be employed to engineer adsorbents with robust iodine uptake behavior.