1 research outputs found
Diamine-Appended Mg<sub>2</sub>(dobpdc) Nanorods as Phase-Change Fillers in Mixed-Matrix Membranes for Efficient CO<sub>2</sub>/N<sub>2</sub> Separations
Despite
the availability of chemistries to tailor the pore architectures
of microporous polymer membranes for chemical separations, trade-offs
in permeability and selectivity with functional group manipulations
nevertheless persist, which ultimately places an upper bound on membrane
performance. Here we introduce a new design strategy to uncouple these
attributes of the membrane. Key to our success is the incorporation
of phase-change metal–organic frameworks (MOFs) into the polymer
matrix, which can be used to increase the solubility of a specific
gas in the membrane, and thereby its permeability. We further show
that it is necessary to scale the size of the phase-change MOF to
nanoscopic dimensions, in order to take advantage of this effect in
a gas separation. Our observation of an increase in solubility and
permeability of only one of the gases during steady-state permeability
measurements suggests fast exchange between free and chemisorbed gas
molecules within the MOF pores. While the kinetics of this exchange
in phase-change MOFs are not yet fully understood, their role in enhancing
the efficacy and efficiency of the separation is clearly a compelling
new direction for membrane technology