Polyphthalonitrile as a novel precursor for carbon membranes: Tunable microstructure characteristics and gas permeation behavior

• Published in: Carbon (New York) Vol. 228; p. 119284
• Main Authors: Hu, Chun-Po, Liang, Yen Nan, Yang, Hong-Li, Hung, Wei-Song, Lim, Jacob Song Kiat, He, Zeming, Hu, Xiao Matthew
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-09-2024
• Subjects: Carbon molecular sieve membrane; Crosslinkable precursor; Polyphthalonitrile; Pore size distribution control; Tunable π-π stacking; Carbon molecular sieve membrane; Tunable π-π stacking; Pore size distribution control; Polyphthalonitrile; Crosslinkable precursor
• ISSN: 0008-6223
• DOI: 10.1016/j.carbon.2024.119284

Carbon molecular sieve (CMS) membranes hold great promise for energy-efficient gas separation, contributing to mitigating greenhouse gas emissions. Exploring new types of microstructurally tunable polymeric precursors is critical for understanding the evolution of carbon microstructure arrangement and adjusting the gas permeation behavior of CMS membranes. As a precursor for CMS membranes, polyphthalonitrile (PPN) resin with both tunable intermolecular distance and π-π stacking arrangement is reported for the first time. We have demonstrated that the aforementioned two key features of the thermally crosslinked PPN network are beneficial to forming PPN-CMS membranes with enlarged intermolecular distance and small-sized, narrow-distributed ultramicropores (<7 Å), thereby improving gas permeability and ideal selectivity. This study provides new insights into the microstructure evolution of PPN-derived microporous carbon materials. Owing to its excellent thermal stability, tunable microstructure arrangement, and flexibility of chemical synthesis, PPN represents a promising class of polymeric precursor materials for fabricating CMS membranes.
[Display omitted]
•Polyphthalonitrile (PPN) as new precursor for carbon molecular sieve (CMS) membrane.•Evolution of microstructure arrangement of PPN-derived carbon was elucidated.•Crosslinking of PPN expands intermolecular distance of CMS, improving permeability.•π-π stacking of PPN forms small, narrow ultramicropore of CMS, raising selectivity.