Abstract
In this work, poly(ionic liquid)–ionic liquid (PIL–IL) composite membranes were prepared using the solvent casting technique. The studied PILs have pyrrolidinium polycation backbone ([Pyr11]+), while the five ILs display either an imidazolium ([C2mim]+) or a pyrrolidinium ([Pyr14]+) based cation. Both the PIL and IL components comprised cyano-functionalized anions ([N(CN)2]–, [C(CN)3]– or [B(CN)4]–), being the anion for each component different from one another. The use of the [NTf2]– anion was also tested for comparison. Several experimental conditions for the solvent casting procedure were tested in order to prepare homogenous and free standing PIL–IL composite membranes. The CO2 and N2 permeation properties (permeability, diffusivity and solubility) were evaluated at a fixed temperature (293 K) and constant trans-membrane pressure differential (100 kPa) using a time-lag apparatus, so that trends regarding the different anions either on the PIL or IL could be obtained and evaluated. From all 42 PIL–IL combinations tested, 21 were suitable membranes (homogeneous and free standing) for gas permeation experiments and 4 of them were on top or surpassed the 2008 Robeson upper bound for CO2/N2 separation. The best performance membranes contain the [C(CN)3]– and [B(CN)4]– anions, enlightening therefore the promise these anions entail for future high performance membranes for post-combustion CO2 separation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.