Ion-Selective Transport Promotion Enabled by Angstrom-Scale Nanochannels in Dendrimer-Assembled Polyamide Nanofilm for Efficient Electrodialysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38949785.
- Also identified by DOI 10.1021/acs.nanolett.4c01997.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The ion permeability and selectivity of membranes are crucial in nanofluidic behavior, impacting industries ranging from traditional to advanced manufacturing. Herein, we demonstrate the engineering of ion-conductive membranes featuring angstrom-scale ion-transport channels by introducing ionic polyamidoamine (PAMAM) dendrimers for ion separation. The exterior quaternary ammonium-rich structure contributes to significant electrostatic charge exclusion due to enhanced local charge density; the interior protoplasmic channels of PAMAM dendrimer are assembled to provide additional degrees of free volume. This facilitates the monovalent ion transfer while maintaining continuity and efficient ion screening. The dendrimer-assembled hybrid membrane achieves high monovalent ion permeance of 2.81 mol m<sup>-2</sup> h<sup>-1</sup> (K<sup>+</sup>), reaching excellent mono/multivalent selectivity up to 20.1 (K<sup>+</sup>/Mg<sup>2+</sup>) and surpassing the permselectivities of state-of-the-art membranes. Both experimental results and simulating calculations suggest that the impressive ion selectivity arises from the significant disparity in transport energy barrier between mono/multivalent ions, induced by the "exterior-interior" synergistic effects of bifunctional membrane channels.