Enabling Targeted Fractionation of Ions via Facilitated Transport Membranes

Introduction

Effective fractionation of ions does not only play a vital role in the functioning of human cell membranes, but also in engineered membranes used to produce drinkable water, extract target minerals, and capture energy to address challenges in environmental, resource, and energy fields.

Challenges in Current Membranes

Nevertheless, most of the state-of-the-art membranes fail to overcome the trade-off between single ion selectivity and throughput. The progress is greatly hampered by the lack of comprehensive understanding of the separation mechanisms across different types of as-claimed ion selective membranes.

Project Objectives

The IonFracMem project will make breakthroughs by designing novel facilitated ion exchange membranes using an interdisciplinary approach based on electrochemistry. This approach synergizes with the interaction between target ions and functional materials to form ion selective sites in the membrane and thus facilitate its transport.

Membrane Types

To achieve a holistic understanding, we will purposely construct two types of membranes with completely different structures for fractionating ions:

1. Polymeric membranes of flexible nature, made of conventional or hydrogel polymers (Obj. 1).
2. Composite membranes of rigid nature, consisting of nanomaterials with sub-nanometer cavities (Obj. 2).

Mechanistic Understanding

Subsequently, we will provide mechanistic understanding of the facilitated transport phenomena via a multi-scale modelling approach (Obj. 3) to identify governing mechanisms that can be translated to membrane fabrication parameters.

Interdisciplinary Integration

The project integrates several key engineering and science disciplines such as:

• Separation technology
• Material processing and functionalization
• Electrochemistry
• Fundamental physics

This integration allows for the rational design of next-generation membranes from a wide range of materials for ion purification.

Impact

The proposed multidisciplinary approach will impact theories and applications of electro-driven membranes in important domains such as water purification, resource recovery, and sustainable energy.