Fluorocarbon adsorption in hierarchical porous frameworks

Abstract

Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of 44 mmol g À 1 at a very low relative saturation pressure (P/P o ) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching 414 mmol g À 1 at P/P o of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane 4chlorodifluoromethane 4chlorotrifluoromethane 4tetrafluoromethane 4methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

Charge-specific size-dependent separation of water-soluble organic molecules by fluorinated nanoporous networks

“…In addition, the fluorine-cation interaction can provide great use in mixed matrix membranes with inorganic cations and fluorinated polymers. Based on our findings, we also suggest that fluorinated molecules can be selectively separated (especially from other halogenated organics) by inorganic porous solids with open metal sites56.…”

CF4 Adsorption on Microporous Carbons Prepared by Carbonization of Poly(vinylidene fluoride)

“…Among the PBPCs evaluated, the highest CF 4 adsorption capacity of 1.85 mol/kg at 25°C and 1 atm was achieved with PBPC800. This adsorption capacity is higher than that of certain reported zeolites, MOFs, and activated carbons: 0.47 and 0.78 mol/kg for zeolite 5A and zeolite 13X, respectively, at 30°C and 1 atm; 18 <1 mol/kg for MIL-101 at 25°C and 1 atm; 19 1.68 mol/kg for Carbosieve G at 25°C and 1 atm. 34 CF 4 adsorption isotherms for PBPC800 were acquired at three different temperatures of 25, 40, and 60°C, and the results are compared in Figure 5b.…”

Microporous metal–organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures

“…This is because the pores within microporous MOFs can be straightforwardly and rationally tuned to enforce their size selective sieving effects while their pore surfaces can be readily functionalized to induce preferential interactions with specific gas molecules567891011121314151617181920212223242526272829303132333435. Although such a potential has been speculated, MOFs for the separation of C 2 H 2 /C 2 H 4 have not been fully explored.…”