Facilitated Transport Membranes (FTMs) have been demonstrated to be effective in simultaneously increasing permeability and selectivity, making them an alternative approach to overcome the permselectivity trade-off experienced by conventional polymer membranes. Despite high performance, metal ion carriers experience photo/chemical aging, which causes, in turn, a rapid decay of their performance. Moreover, when embedded in polymer materials, structural defects may form at the metal-polymer interface that, despite accelerating small molecule transport, cause a parallel selectivity loss. To address the issues mentioned above, we fabricated silver nanoparticles (NPs) stabilized using a polymer derived from 4,4-oxydiphthalic anhydride and a polyetheramine, Jeffamine. In conjunction with the metal core, polymer agents may be used to provide not only prevention of NP aggregation, but also to evoke Janus transport properties through the simultaneous targeting of the diffusivity and solubility selectivity of dense polymer films. Additionally, these polymer agents can mediate an interphase between silver and the bulk polymer, while offering carrier sites protection from photo/chemical degradation. In this study, Janus nanoparticles for CO2 separation were rationally designed and synthesized by chelating silver nanoparticles with poly(amic-acid)s (PAAs). The inclusion of ether functional groups into the polymer chain further enhances CO2 permeability and selectivity by positively affecting CO2 sorption mechanics. The synthesized silver-PAA nanoparticles, which were thoroughly characterized via TEM/EDS analysis, showed near spherical morphology (~5 nm) and lack of aggregation. The effect of the PAA length and ether functional group concentration on the structure and transport properties of nanoparticles were systematically investigated. The silver-PAA Janus nanoparticles were then embedded into a commercial polymer, Pebax, to fabricate defect-free mixed matrix membranes for CO2/CH4 separation, whose structure and transport properties were examined at various NP loadings. The mixed matrices exhibited enhanced permeability and selectivity relative to neat Pebax.

Synthesis and characterization of Janus mixed matrix membranes for CO2 separation

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.