TY - JOUR
T1 - A monolithic composite based on zeolite-like metal-organic framework@divinylbenzene polymer separates azeotropic fluorocarbon mixture efficiently.
AU - Yusuf, Kareem
AU - Shekhah, Osama
AU - Aqel, Ahmad
AU - Alharbi, Seetah
AU - Alghamdi, Ali S
AU - Aljohani, Reem M
AU - Eddaoudi, Mohamed
AU - ALOthman, Zeid A
N1 - KAUST Repository Item: Exported on 2023-03-21
Acknowledgements: This work was supported through the project funded by the National Plan of Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, Grant Number 14-ADV2447–02.
PY - 2023/3/15
Y1 - 2023/3/15
N2 - Organic monolithic columns are mainly used to separate macromolecules; however, many attempts to extend their performance toward small molecules were examined by incorporating micro- and nanoparticles. The incorporation technique enabled utilizing organic monoliths in gas chromatography (GC) for small molecules, which are still scarce. Here, we prepared a composite matrix of capillary monolithic columns of a zeolite-like metal-organic framework with a sodalite topology (sod-ZMOF) and Divinylbenzene polymer (DVB) for GC separations under 0.5 MPa. Relatively short DVB monolithic columns (18 cm long × 0.25 mm i.d.) incorporated with a tiny amount of sod-ZMOF nanoparticles (0.7 and 1.17 wt%) with an average particle size of 225 nm were successfully fabricated and used to separate linear alkanes and polar probes mixtures with increasing resolution up to 3.7 and 5.1 times, respectively, compared to a blank DVB monolithic column. A high-performance separation of linear alkanes series mixture (methane to decane) was exhibited in less than 2 min. McReynolds constants revealed that sod-ZMOF provided the composite monolith with a nonpolar character yielding a negative average polarity value smaller than the standard squalene column. An Excellent retention time of pentane and octane day-to-day reproducibility was achieved during 16 days and over more than 500 runs with RSD% of 2.25% and 3.3% using a composite monolithic column with 5 mg mL−1 sod-ZMOF (5-ZMOF@DVB). In addition, a qualitative determination of the gas mixture content of three commercially available Lighter gas cartridges was performed via the 5-ZMOF@DVB column. Finally, successfully separating an azeotropic freon mixture of difluoromethane (R-32) and pentafluoroethane (R-125) was achieved with a selectivity of up to 4.84. A further thermodynamic study related the preferential adsorption of R-125 to entropic factors rather than enthalpic while trapping inside ZMOF pores. This work sheds light on utilizing the infinite diversity of MOFs and combining their properties with high permeability and easily fabricated organic monoliths for GC separations of light molecules and gasses. Furthermore, the study highlights the role of GC as an easy and fast approach for the preliminary evaluation of the separation efficiency of porous polymers.
AB - Organic monolithic columns are mainly used to separate macromolecules; however, many attempts to extend their performance toward small molecules were examined by incorporating micro- and nanoparticles. The incorporation technique enabled utilizing organic monoliths in gas chromatography (GC) for small molecules, which are still scarce. Here, we prepared a composite matrix of capillary monolithic columns of a zeolite-like metal-organic framework with a sodalite topology (sod-ZMOF) and Divinylbenzene polymer (DVB) for GC separations under 0.5 MPa. Relatively short DVB monolithic columns (18 cm long × 0.25 mm i.d.) incorporated with a tiny amount of sod-ZMOF nanoparticles (0.7 and 1.17 wt%) with an average particle size of 225 nm were successfully fabricated and used to separate linear alkanes and polar probes mixtures with increasing resolution up to 3.7 and 5.1 times, respectively, compared to a blank DVB monolithic column. A high-performance separation of linear alkanes series mixture (methane to decane) was exhibited in less than 2 min. McReynolds constants revealed that sod-ZMOF provided the composite monolith with a nonpolar character yielding a negative average polarity value smaller than the standard squalene column. An Excellent retention time of pentane and octane day-to-day reproducibility was achieved during 16 days and over more than 500 runs with RSD% of 2.25% and 3.3% using a composite monolithic column with 5 mg mL−1 sod-ZMOF (5-ZMOF@DVB). In addition, a qualitative determination of the gas mixture content of three commercially available Lighter gas cartridges was performed via the 5-ZMOF@DVB column. Finally, successfully separating an azeotropic freon mixture of difluoromethane (R-32) and pentafluoroethane (R-125) was achieved with a selectivity of up to 4.84. A further thermodynamic study related the preferential adsorption of R-125 to entropic factors rather than enthalpic while trapping inside ZMOF pores. This work sheds light on utilizing the infinite diversity of MOFs and combining their properties with high permeability and easily fabricated organic monoliths for GC separations of light molecules and gasses. Furthermore, the study highlights the role of GC as an easy and fast approach for the preliminary evaluation of the separation efficiency of porous polymers.
UR - http://hdl.handle.net/10754/690486
UR - https://linkinghub.elsevier.com/retrieve/pii/S0021967323001486
U2 - 10.1016/j.chroma.2023.463922
DO - 10.1016/j.chroma.2023.463922
M3 - Article
C2 - 36931139
SN - 0021-9673
VL - 1694
SP - 463922
JO - Journal of chromatography. A
JF - Journal of chromatography. A
ER -