RESUMO
Molecular dynamics simulations evidenced a structural transition of the flexible MIL-53(Cr) under a relatively moderate applied pressure ~50 MPa. The incorporation of CO(2) within its porosity significantly shifts the onset of such a transformation at lower pressure while it decreases the bulk modulus of this solid.
RESUMO
A new force field that can describe the flexibility of Cu-BTC metal-organic framework (MOF) was developed in this work. Part of the parameters were obtained using density functional theory calculations, and the others were taken from other force fields. The new force field could reproduce well the experimental crystal structure, negative thermal expansion, vibrational properties as well as adsorption behavior in Cu-BTC. In addition, the bulk modulus of Cu-BTC was predicted using the new force field. We believe the new force field is useful in understanding the structure-property relationships for MOFs, and the approach can be extended to other MOFs.
Assuntos
Cobre/química , Simulação de Dinâmica Molecular , Compostos Organometálicos/química , Ácidos Tricarboxílicos/química , Adsorção , Simulação por Computador , Cristalografia , Metais , Modelos MolecularesRESUMO
Capillary phase transitions of CH(4) confined in a series of metal-organic frameworks (MOFs) were investigated in this work using gauge cell Monte Carlo simulations. The results show that capillary phase transitions can occur in MOFs, and the effects of temperature, pore size, and adsorption energy are very significant. Furthermore, this work shows the confinement can induce a shift in critical point for fluids confined in MOFs, leading to a decrease in critical temperature and an increase in critical density. The critical point shift is more obvious for MOFs with small pore size and large adsorption energy.
