ZIF nanoparticles and membrane characterizations
Powder X-ray diffraction (PXRD)
and Wide-angle X-ray diffraction (WXRD) patterns were determined for
ZIFs nanoparticles and membranes by using an X-ray diffractometer
(Ultima IV, Japan) with Cu-Kα X-ray radiation (λ =1.54056 Å) from 5 to
40º at the rate of 5o min-1,
respectively. For testing the textural properties of synthesized ZIFs
materials surface area analyzer (BELSORP Japan) was used by
N2 adsorption and desorption at 77 K. The surface areas
of ZIF-8 and Ni-ZIF-8 were calculated by the use of standard
Brunauer-Emmett-Teller (BET) equation. Before measuring the surface
area, the samples were pre-dried at 150ºC for 6 hrs under a continuous
flow of N2. Morphologies and Energy disperse X-ray
spectroscopy (EDXS) of the ZIFs particles, and MMMs were observed
through a field-emission scanning electron microscope (FE-SEM,
JSM-7500F, JEOL, Japan), which was operated at 5 kV. FTIR spectrum was
plotted by using ATR-FTIR (Thermo Nicolet IS10, USA) by setting the
range of 4000–500 cm-1 with a resolution of 4
cm-1. Thermal stabilities analysis of the
nanoparticles and MMMs were analyzed by thermogravimetric analysis
(TGA-60 Shimadzu Japan) in the range of 30 to 800ºC with a ramp rate of
5ºC min-1, under the continuous flow of nitrogen. The
same instrument (TGA-60 Shimadzu Japan) was used for differential
scanning calorimetry (DSC) analysis of MMMs.