1. Understanding hydrogen solubility and free volume characteristics in charge-transfer phthalonitrile prepolymer and polyimide blend membranes.
- Author
-
Hu, Chun-Po, Lim, Jacob Song Kiat, Ping, Kuo-Hsiang, Hung, Wei-Song, Liang, Yen Nan, and Hu, Xiao Matthew
- Subjects
- *
BENZENEDICARBONITRILE , *POLYIMIDES , *POLYMERIC membranes , *SOLUBILITY , *GAS separation membranes , *ELECTRON donors , *HYDROGEN production - Abstract
The increasing demand for hydrogen production has necessitated the development of H 2 -selective membranes. Polyimides are excellent membrane materials for gas separation; however, commercial polyimides generally lack sufficient H 2 selectivity due to their low H 2 affinity. Understanding the relationship between gas transport properties and free volume microstructure is critical to advancing H 2 -selective membrane design. Herein, we report a facile material strategy to adjust the free volume characteristics and H 2 separation performance via blending Matrimid (PI) and crosslinkable resorcinol-based phthalonitrile prepolymer (RPN) with electron donor/acceptor properties. The novel RPN30/PI70 membrane exhibits H 2 /N 2 and H 2 /CO 2 permselectivity of 1637 and 66.4, respectively, with H 2 permeability of 2.7 Barrer in pure gas test, surpassing Robeson upper bounds (2008). The increased H 2 permselectivity of RPN/PI membranes was attributed to the narrowed free volume size and distribution, giving rise to the considerably improved H 2 solubility and selectivity of the blends. Moreover, the H 2 permeability of crosslinked RPN30/PI70 membranes can be further improved via thermal treatment. The H 2 /CO 2 mixed-gas test reveals that the H 2 gas separation performance of the RPN30/PI70 membrane is influenced by plasticization effect and competitive sorption. This study demonstrates a new versatile strategy for designing high-performance hydrogen-selective polymeric membranes. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF