Mixed matrix membranes comprising of fluorinated and sulfonated PEEK and functionalized mesoporous COK-12 for CO2 separation

A. L. Khan*, COMSATS Institute of Information Technology, Pakistan; S. P. Sree, J. A. Martens, I. F. J. Vankelecom, KU Leuven, Belgium; Xianfeng Li, Chinese Academy of Sciences, China

The excessive use of fossil fuels such as coal and petroleum products is one of the primary sources of CO2 emissions. CO2 thus emitted is a major contributor to the greenhouse effect of earth, resulting in increase in global warming. Membrane technology is an attractive choice to perform this task due to its many advantages over other separation techniques such as environment friendly, cheap and energy efficient1. Mixed matrix membranes (MMMs) comprising of an inorganic filler and a polymer matrix have shown the potential to increase the performance of gas separation membranes1.

In this study, new types of MMMs composed of novel polymer, a fluorinated and sulfonated aromatic poly (ether ether ketone) (FSPEEK) and –SO3 functionalized mesoporous silica spheres were prepared by solution casting method. The dispersion of the fillers in the polymer matrix was improved by employing solution blending and probe sonication techniques. The thickness of the membranes was controlled at 50-65 µm. Sulfonated polymers have shown their potential to surpass the Robeson upper bound2-3. The incorporation of bulky fluorinated groups in the polymer is expected to further increase the separation performance due to inhibition of chain packing and increased steric hindrance4. The presence of C2F6 type fluorinated groups improves the fractional free volume by the inhibition of chain packing. These bulky groups also restrict the torsional motion of the polymeric chains and simultaneously increase the rigidity of polymer resulting in strong ability of size sieving. The degree of sulfonation was fixed at 50% for all the synthesized MMMs.

CO2 permeation and SEM images of the synthesized MMMs suggest that the fillers adhered well to the polymer matrix. The non-functionalized COK-12 based MMMs showed up to 26% increase in...

Session: M2 - New Membranes II
Day: 14 March 2018
Time: 10:45 - 12:00 h

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