Solution-diffusion properties of C4H6 and N2 molecules in
zeolitic-imidazolate framework based mixed matrix membranes
Abstract
This research investigated comprehensively the fundamental science of
estimating sorption, diffusion, and permeation of 1,3-butadiene and
nitrogen in polydimethylsiloxane (PDMS), and zeolitic imidazolate
frameworks (ZIFs) filled mixed-matrix membranes (MMMs). ZIF-8 and
Ni-ZIF-8 nanocrystals were synthesized at room temperature and
incorporated into PDMS at different loadings. The physical and chemical
properties of both ZIFs have been studied by XRD, FTIR, SEM, EDX, and
TGA, respectively. Synthesized Ni-ZIF-8/PDMS MMMs demonstrated
homogeneous particle dispersion, improved particle-polymer adhesion, and
better butadiene permeation under various testing conditions. 15%
Ni-ZIF-8/PDMS MMM exhibits 1,3-butadiene permeance 323 GPU, which
improved by 60% compared with PDMS, and 32% with 15% ZIF-8/PDMS MMM,
while BD/N2 ideal selectivity of 19.5was higher 81% than PDMS, and 32%
than 15% ZIF-8/PDMS MMM at 40°C and 1.5 bar. Additionally,
Ni-ZIF-8/PDMS MMMs have improved the solution-diffusion properties of
butadiene and decreased sorption enthalpy, entropy change, activation
energies of diffusion, and permeability from PDMS and ZIF-8/PDMS.