A molecular simulation study for efficient separation of 2,5-furandiyldimethanamine by a microporous polyarylate membrane

We report a molecular simulation study for the efficient separation of high-value 2,5-furandiyldimethanamine (FDA) by a microporous polyarylate membrane (5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane, PAR-TTSBI). With a contorted backbone, the membrane possesses high microporosity and interconnectivity. First, the swelling behavior of the PAR-TTSBI membrane in different solvents (methanol, acetonitrile and acetone) is examined. The swelling degree (SD) is found to increase in the order of acetone < acetonitrile < methanol, and governed by the interaction between the PAR-TTSBI and solvent; the strongest interaction in methanol leads to the largest SD. Then, solvent permeation through the swollen PAR-TTSBI is simulated. The solvent permeabilities are predicted to increase as acetone < acetonitrile < methanol, which follows the increasing trend of SD. In the presence of FDA, the permeability of each solvent drops considerably due to the accumulation of FDA molecules at the membrane interface. In each solvent, FDA retention is observed to be 100%. The simulation study provides microscopic understanding in the swelling and permeation of the PAR-TTSBI membrane; with the excellent FDA retention and high solvent permeability, the membrane could be an interesting candidate for the separation of FDA.