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Updated: Jul 2, 2025

Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
Switchable Asymmetric Water Transport in Dense Nanocomposite Membranes
Luca Grillo1, Christoph Weder1
1Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.
Abstract:
Directional water transport is technologically relevant in separation processes, functional clothing, and other applications. While asymmetric water transport characteristics are a vital feature of leaf cuticles, examples of artificial membranes that display this effect are limited. Here, we report compositionally asymmetric membranes that are based on hydrophobic poly(styrene)-block-poly(butadiene)-block-poly(styrene) (SBS) and hydrophilic poly(vinyl alcohol) (PVA) nanofibers and display directional water transport when a high relative humidity (RH) gradient is applied. This effect is caused by the asymmetric structure of the membrane and the fact that the water permeability of PVA depends on the water pressure applied and the extent of plasticization that it causes. The transport characteristics can be tuned by varying the composition of the membranes. Such materials with switchable asymmetric water transport may be useful for smart packaging applications in which the take-up or release of water is regulated as needed.
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