Artificial Water Channels Form Precursors to Sponge-Like Aggregates in Water–Ethanol Mixtures

Arthur Hardiagon (1) , Marc Baaden (1) , Fabio Sterpone (1)

1 LBT (UPR_9080) - Laboratoire de biochimie théorique [Paris]

Self-assembled Artificial Water Channels (AWCs) are reshaping current water desalination technologies. Recently, the improvements achieved by incorporating hydrophilic compounds into polyamide membranes (PA) at the interface have been experimentally confirmed. However, the determination of the nanoscale structure of AWCs remains unclear. An important step in the preparation of PA membranes is solubilization by colloidal suspension of the solid phase in a water-ethanol mixture. We perform molecular dynamics simulations to study the nanoscale structure of AWC aggregates. We characterize the size and shape of the aggregates at several key locations in the ternary phase diagram. The role of ethanol in forming the interface between the solvent and the solute phase is highlighted. We found that the structure of the aggregates formed in the ternary solution resembles the disordered sponge-like structures observed when AWCs were inserted into lipid membranes. Such permeable sponge architectures allow the passage of water despite their non-crystalline organization and have been previously shown to be consistent with AWC permeation measurements in membrane environments.

Domaines: Chimie théorique et/ou physique

Arthur Hardiagon, Marc Baaden, Fabio Sterpone. Artificial Water Channels Form Precursors to Sponge-Like Aggregates in Water–Ethanol Mixtures. Journal of Physical Chemistry A, 2022, 126 (38), pp.6628-6636. ⟨10.1021/acs.jpca.2c04545⟩. ⟨hal-03873715⟩