Nonpreferential Solvent Transport through an Intrinsic Cyclodextrin Pore in a Polyester Film

We performed equilibrium molecular dynamics simulations to study the transport of water and hexane solvents through cyclodextrin(CD)-based membranes (α-/β-/γ-CD/TMC). Although it is known that water and hexane can permeate through the macrocyclic cavity, surprisingly, when it is present in the CD-based membrane (α-/β-/γ-CD/TMC), these solvents are not permeating through the CD cavity. Interactions between membrane functional group atoms with the water and hexane suggest that these solvents primarily permeate through the polar aggregate pores formed via ester-linkage rather than the CD cavity. Our observation reveals that both solvents can permeate through the membrane; however, the hexane flux was one order of magnitude lower than water flux. Our study suggests that further work is needed to confirm the functional significance of the macrocyclic cavity in solvent permeation and the existence of Janus pathways.