RT info:eu-repo/semantics/article
T1 The effect of humidity on the CO2/N2 separation performance of copolymers based on hard polyimide segments and soft polyether chains: Experimental and modeling
A1 Olivieri, Luca
A1 Tena, Alberto
A1 De Angelis, Maria Grazia
A1 Hernández Giménez, Antonio
A1 Lozano, Angel E.
A1 Sarti, Giulio Cesare
AB In this work, we studied two copolymers formed by segments of a rubbery polyether (PPO or PEO) and of a glassy polyimide (BPDA-ODA or BKDA-ODA) suitable for gas separation and CO2 capture. Firstly, we assessed the absorption of water vapor in the materials, as a function of relative humidity (R.H.), finding that the humidity uptake of the copolymers lies between that of the corresponding pure homopolymers values. Furthermore, we studied the effect of humidity on CO2 and N2 permeability, as well as on CO2/N2 selectivity, up to R.H. of 75%. The permeability decreases with increasing humidity, while the ideal selectivity remains approximately constant in the entire range of water activity investigated. The humidity-induced decrease of permeability in the copolymers is much smaller than the one observed in polyimides such as Matrimid® confirming the positive effect of the polyether phase on the membrane performance.Finally, we modeled the humidity-induced decrease of gas solubility, diffusivity and, consequently, permeability, using a suitable approach that considers the free volume theory for diffusion and LF model for solubility. Such model allows estimating the extent of competition that the gases undergo with water during sorption in the membranes, as a function of the relative humidity, as well as the expected reduction of free volume by means of water molecules occupation and consequent reduction of diffusivity.
SN 2468-0257
YR 2016
FD 2016
LK https://uvadoc.uva.es/handle/10324/83073
UL https://uvadoc.uva.es/handle/10324/83073
LA spa
NO Green Energy & Environment 1 (2016) 201e210
DS UVaDOC
RD 03-abr-2026