metal-organic frameworks (mofs): application in the separation sciences

Metal-organic frameworks (mofs) have received great attention due to their fascinating structures and intriguing utilization in diverse applications [1]. here, the recent advances in the design and synthesis of mofs with hierarchical porosity across the micro- and mesoporous for application as adsorbent for spe and spme methods as well as stationary phase of chromatography are summarized. some examined mofs have exhibited a good selectivity for adsorption of different compounds that is not seen in other materials, such as zeolites and activated carbon [2]. recently, porous mofs have been introduced good alternatives as stationary phases for chromatography (including gas- and liquid-phase), because they are crystalline and have high pore volume as well as tunable pore sizes/shapes. it has been demonstrated that some mofs have exceptional thermal stability and high selectivity for application as separation medium in high-resolution gas chromatography [3]. reverse shape selectivity and molecular sieving effect have been explored for capillary gas chromatographic separation of alkane isomers and benzene homologues on uio-66 coated capillary column [4]. in addition, mofs have been used as a new excellent separation medium in liquid chromatography due to their uniform morphology, good dispersion, and solvent stability. in a work, mil-100(fe) was explored as a novel stationary phase for both normal phase and reverse-phase high performance liquid chromatography [5]. the preparation of pure crystalline phase mof monolith with a porous structure containing micropores, mesopores and macropores has been also reported for utilization as liquid chromatography stationary phase [6]. the presence of macropores may be particularly useful in improving mass transport for applications involving liquid phase. in addition, fabrication of mil-100(fe) coated open tubular capillary columns for use in capillary electrochromatography has been reported for separation of neutral, basic and acidic compounds [7]. also, some authors have presented chiral chromatographic columns for the separation of some racemic mixtures over enantiopure porous mof stationary phases [8]. herein, the applications of mofs in separation sciences are reviewed.