Project Focus

Separation

Homogenous mixed-matrix membranes: matrimid membranes filled with 20 wt.% MIL-101. MIL-101 was modified by Diethylenetriamin (DETA) and/or different metal ions.
© Fraunhofer IGB Stuttgart

Homogenous mixed-matrix membranes: matrimid membranes filled with 20 wt.% MIL-101. MIL-101 was modified by Diethylenetriamin (DETA) and/or different metal ions.

SEM picture of a matrimid membrane filled with 20 wt.% MIL-101 shows an homogenous distribution of MOF particles in the polymer matrix.
© Fraunhofer IGB Stuttgart

SEM picture of a matrimid membrane filled with 20 wt.% MIL-101 shows an homogenous distribution of MOF particles in the polymer matrix.

Rel. permeability and selectivity as a function of the MOF-contents. The polymer matrix is matrimid.
© Fraunhofer IGB Stuttgart

Rel. permeability and selectivity as a function of the MOF-contents. The polymer matrix is matrimid.

In this part of the project MOF-mixed-matrix membranes for gas separation are developed. An important prerequisite for membranes with a high performance is the use of well dispersed, nanoscaled MOF crystals. This is the base for homogenous mixed-matrix membranes.

We started with a screening of suitable MOF materials and polymer matrices. With the most promising approaches (polymers: matrimid, silicone-block-copolymers; MOF: ZIF-8, MIL-101) we have manufactured membranes. We varied both the MOF contents and the functionalization of the MOFs and tested the gas transport properties of the resulting membranes for gases like (CO2, H2, CH4, N2, etc.). So far, ZIF-8 matrimid membranes show the best separation properties. By the addition of ZIF-8 the CO2-permeability is doubled, while the CO2/N2-selectivitis is increased by 20 %.