ABSTRACT
The tuning of metal-organic framework (MOF) nanosheet stacking modes from molecular level was rarely explored although it significantly affected the properties and applications of nanosheets. Here, the different stacking modes of Zr-1, 3, 5-(4-carboxylphenyl)-benzene framework nanosheets were synthesized through the induction of different host-guest noncovalent interactions. The solvents of methyl benzene and ethyl acetate induced twisted stacking of nanosheets with the specific rotation angles of 12°, 18°, 24° and 6°, 18°, 24°, 30°, respectively, which was in agreement with theoretical calculations. Meanwhile, the alkanes were likely to vertically enter the pores of Zr-BTB nanosheets because of steric hindrance and hydrophobic interactions, resulting in the untwisted stacking of nanosheets. The untwisted ordered nanopores showed the excellent gas chromatographic separations of benzene derivative isomers, which was better than twisted nanosheets stacking and commercial columns. This work uncovers a rational strategy to control the stacking of two-dimensional MOF nanosheets.
ABSTRACT
Metal-organic frameworks (MOFs) have been applied in various fields because of their fascinating structures and excellent properties. MOFs can serve as stationary phases in gas chromatography (GC), which has led to exceptional improvements of performance. Here, we summarize the application of MOFs in GC based on the classification of analytes. The advantages and separation mechanism of MOFs as stationary phases in GC are discussed in combination with the characteristics and structures of MOFs. The limitations are also summarized in this review, which can provide prospects on further research for the applications of MOFs.
