Desilylation of fluorene-naphthalene polyacetylenes: Towards ultra-permeable gas separation membranes

Poly(substituted acetylene)s with rigid backbones have emerged as attractive candidates for high-performance gas separation membranes. Here, we report a series of fluorene-naphthalene-based acetylene copolymers ( Copoly(Flu-Naph) s) with systematically tuned compositions and their desilylated derivatives ( DScopoly(Flu-Naph) s) for advanced gas separation applications. Gas permeability measurements revealed that the Copoly(Flu-Naph)(4:1) membrane exhibited exceptional oxygen permeability (9,700 Barrer). Further, desilylation enhanced performance, with DScopoly(Flu-Naph)(1:1) reaching an ultrahigh P O2 of 17,000 Barrer. XRD analysis indicated that desilylation increased interchain spacing, and N 2 adsorption measurements confirmed a high BET surface area resulting from the reorganization of the microporous structure. Additionally, the membranes showed excellent thermal stability and favorable resistance to physical aging. These results indicate that fluorene-naphthalene copolymer architecture combined with desilylation has the potential to develop ultra-permeable membranes for gas separation applications. • Novel fluorene-naphthalene-based acetylene copolymers for gas separation membranes. • Desilylation yields ultrahigh oxygen permeability of 17,000 Barrer. • Desilylation significantly enhances microporosity and BET surface area. • Membranes show excellent aging resistance with >80% O 2 retention after 240 days. • Desilylated copolymer architecture offers a new paradigm for designing membranes.