PhD project

Structure-Prosperities Relationship in Ion Exchange Membrane

Xiuqin Wang (PhD Candidate), Rob Lammertink (promotor)

Duration: 2018-2022

Funding: China Scholarship Council (CSC)

In the field of the development of next-generation polymer electrolyte membranes, high conductivity is often regarded as the first important performance requirement. However, there is still a huge challenge to face, that is the contradiction of high ion conductivity corresponding to the good mechanical-dimensional stability.

Key words
Polyelectrolyte membranes, ion transportion, polymer structures design, morphology study

Technological challenges
To date, grafting polymers, dense functional group polymers, self-phase separation structure block polymers and all kinds of functional filler materials have been extensively studied and show enormous potential in tackling this ubiquitous trade-off by increasing the ion-exchange capacity (IEC) and constructing well-connected ion channels. 
However, an in-depth understanding of ion transport through the membranes is still lacked.  The microphase separation structure can indeed provide efficient ion transport channels, but the accurately design and construct specific morphology is a great challenge. Besides, the interaction between ionic groups and the backbone can also cause a close and inseparable influence.

Research goals 
In this project we will explore the optimal ion transport in polyelectrolyte membranes. We use the commercialized block copolymer SEBS through a simple blending method to study and control the influence of the specific morphology on ion transport. Secondly, the homopolymers with the same main chain and differ side chains were home-made to study the effect of ionic groups on membrane performance.

These studies will make them a model system to understand ion transport at different morphology and ionic atmosphere and to provide a rational membrane design principle.