TY - JOUR
T1 - Comparing amine- and ammonium functionalized silsesquioxanes for large scale synthesis of hybrid polyimide high-temperature gas separation membranes
AU - Radmanesh, Farzaneh
AU - Pilz, Monika
AU - Ansaloni, Luca
AU - Peters, Thijs A.
AU - Louradour, Eric
AU - van Veen, Henk
AU - Høvik, Dag
AU - Hempenius, Mark A.
AU - Benes, Nieck E.
N1 - Funding Information:
This work is part of the GENESIS project and the authors acknowledge the financial support from the European Union's Horizon 2020 Research and Innovation Program under the Grant Agreement No. 760899 . This publication reflects only the author's views and the European Union is not liable for any use that may be made of the information contained therein.
Funding Information:
This work is part of the GENESIS project and the authors acknowledge the financial support from the European Union's Horizon 2020 Research and Innovation Program under the Grant Agreement No. 760899. This publication reflects only the author's views and the European Union is not liable for any use that may be made of the information contained therein.
Publisher Copyright:
© 2021 The Authors
PY - 2021/11/1
Y1 - 2021/11/1
N2 - PolyPOSS-imide membranes are promising for separating H2 from larger molecules (CO2, N2, CH4) at temperatures up to 300 °C. Their fabrication involves two steps: interfacial polymerization of POSS and 6FDA, followed by thermal imidization. This work provides a systematic study of the effects of cations on membrane properties and performance. For this, two distinct POSS molecules were used: functionalized with -NH3+Cl− or, so far unexplored, -NH2. The ammonium groups are partially deprotonated by using three different bases, LiOH, NaOH, and KOH. We demonstrate that the introduced cations affect the film thickness but not the molecular composition of the polyamic acid. All polyamic acids can be imidized, but the cations reduce the imidization kinetics as well as the loss of organic crosslinkers. For flat disc membranes, at 200 °C, the absence of cations results in comparable permeability combined with higher selectivity for H2/N2. This, and the possibility to discard adding a base, motivated a scale-up study of the new POSS. For tubular membranes, much higher ideal and mixed gas selectivities are found than for membranes where NaOH was added. Results indicate that the new route allows more reproducible production of defect free membranes and has potential for larger-scale polyPOSSimide fabrication.
AB - PolyPOSS-imide membranes are promising for separating H2 from larger molecules (CO2, N2, CH4) at temperatures up to 300 °C. Their fabrication involves two steps: interfacial polymerization of POSS and 6FDA, followed by thermal imidization. This work provides a systematic study of the effects of cations on membrane properties and performance. For this, two distinct POSS molecules were used: functionalized with -NH3+Cl− or, so far unexplored, -NH2. The ammonium groups are partially deprotonated by using three different bases, LiOH, NaOH, and KOH. We demonstrate that the introduced cations affect the film thickness but not the molecular composition of the polyamic acid. All polyamic acids can be imidized, but the cations reduce the imidization kinetics as well as the loss of organic crosslinkers. For flat disc membranes, at 200 °C, the absence of cations results in comparable permeability combined with higher selectivity for H2/N2. This, and the possibility to discard adding a base, motivated a scale-up study of the new POSS. For tubular membranes, much higher ideal and mixed gas selectivities are found than for membranes where NaOH was added. Results indicate that the new route allows more reproducible production of defect free membranes and has potential for larger-scale polyPOSSimide fabrication.
KW - Gas separation
KW - Interfacial polymerization
KW - Polyimide
KW - POSS
KW - Thermal stability
KW - UT-Hybrid-D
U2 - 10.1016/j.memsci.2021.119524
DO - 10.1016/j.memsci.2021.119524
M3 - Article
AN - SCOPUS:85111054026
SN - 0376-7388
VL - 637
JO - Journal of membrane science
JF - Journal of membrane science
M1 - 119524
ER -