Fabrication of MMMs
Before membrane fabrication, the PSF powders, MOF NPs, and pMOF MSs were
dried in vacuum at 100 °C overnight to remove the adsorbed water. The
MOF NPs and pMOF MSs were employed as fillers. As shown in Eqs. (1) and
(2), the amount of the solid substances (polymers and fillers) were 10
wt% of the mixtures, while the fillers accounted for 10 wt% of the
solid substances. The fillers were first dispersed in
CHCl3 to prepare the initial suspension, followed by
constant stirring and ultrasonic treatment for 2 h. The PSF powders were
added into the above suspension and then stirred overnight. To
completely remove the air bubbles, the casting ink was ultrasonically
treated for 5 min and stirred for 5 min, repeating this process for 6
times and then standing for 1 h. The prepared viscous membrane ink was
poured on a glass plate and casted with a scraper. After standing at
room temperature for 1 h, the formed membrane was placed in an oven at
50 °C for 4 h, and then dried in vacuum at 80 °C overnight to completely
evaporate the residual solvent. The pure PSF membrane was prepared by
the same method as above.
\(\frac{\text{PSF}+\text{MOF}}{\text{\ PSF}+MOF+\text{CHCl}_{3}}=10\ wt\%\)(1)
\(MOF\ loading\ (wt\%)=\frac{\text{MOF}}{\text{PSF}+MOF}\times 100=10\ wt\%\)(2)