Influence of the molecular structure of polybinaphthalene on the membrane separation performance

To study the influence of the molecular structure of polybinaphthalene on the gas separation membrane properties, a binaphthalene is bridged with four different linkers (methylene to butylene) and copolymerized with two co-monomers of different length. However, the linkers do not significantly change the binaphthalene dihedral angles as reported previously. Consequently, the polybinaphthalene have similar macromolecular structure as demonstrated by CD spectroscopy and DFT calculations. These results confirm the similar gas selectivities observed with the polybinaphthalene membranes. Moreover, the influence of the co-monomer length on the membrane separation is not noticed.