Effect of Ag2O nanoparticles on long-term stable polymer/AgBF4/Al(NO3)3 complex membranes for olefin/paraffin separation

- Olefin/paraffin separation membranes consisting of PVP/AgBF4/Al(NO3)3/Ag2O nanoparticles composite.
- Enhanced separation performance in both mixed-gas selectivity and permeance by incorporation of Ag2O nanoparticles.
- The barrier effect of Ag2O nanoparticles for propane molecules and the enhanced activity of Ag ions as olefin carriers.

The effect of Ag2O nanoparticles on long-term stable poly(vinylpyrrolidone) (PVP)/AgBF4/Al(NO3)3 complex membrane was investigated for olefin/paraffin separation. Even though PVP/AgBF4/Al(NO3)3 complex membrane showed the long-term stability by effect of Al(NO3)3, the relatively low separation performance was observed, especially mixed-gas permeance. Thus, Ag2O nanoparticles were incorporated into PVP/AgBF4/Al(NO3)3 complex membrane for the enhanced separation performance. When PVP/AgBF4/Al(NO3)3/Ag2O nanoparticles composite membrane was prepared, they showed substantially enhanced performance for separation of the propane/propylene gas mixture, with a selectivity of 21.7 and permeance of 4.3 GPU while PVP/AgBF4/Al(NO3)3 membrane showed 1.3 GPU with a selectivity of 15.0. FT-IR, TGA, and Raman analyses demonstrated that the enhanced separation performance induced by Ag2O nanoparticles was mainly related to two factors: (1) silver(I) oxide functioned as barrier for propane and (2) the interaction of the Ag ion and the oxygen of Ag2O could enhance the activity of Ag ions as olefin carriers.