Figure 11: Gas separation
performance for AgZIF-62 at different composite states (ZIF-zni vs ZIF
glass) for a)CO2, N2 and
CH4 based separation, b)ethylene/ethane-based
separation, and c)propylene/propane-based separation.
Further analysis of the effect of Ag-loaded thermally treated ZIF type
(ZIF-zni and amorphous ZIF glass) on gas separation performance was also
studied, as can be seen in Figure 11. The performance of the presence of
Ag nanoparticles in ZIF-62 glass was also compared to pure ZIF-62 glass.
The selectivity of all gas pairs studied shows no significant increase
when the pure 6FDA-DAM polymer was loaded with mZIF-62-a, despite an
increase in gas permeability. This may be attributed to possible void
formation between mZIF-62-a towards its surrounding 6FDA-DAM polymer
matrix. The gas performance of all gas pairs for 6FDA-DAM mixed membrane
systems loaded with silver nanoparticles (mAgZIF-62-a and mAgZIF-62-c)
consistently show improvements in both selectivity and permeability no
matter the ZIF types (ZIF-zni or amorphous ZIF glass). This demonstrates
the accessibility of silver in thermally treated ZIF-62 irrespective of
phase, which is important to ensure that the silver can be accessed for
other applications too. The accessibility of silver for both ZIF-zni and
amorphous ZIF glass also demonstrates that silver nanoparticle
immobilisation/functionalisation can be applied for both ZIF material
types to suit their respective future applications.