Electrospinning for production of 3D-structured bipolar membranes for water dissociation applications

In water technology, the demand for bipolar membranes is steadily rising. Bipolar membranes split water into protons and hydroxyl ions allowing the industrial on-site production of e.g. acid and base. At Wetsus we are developing many novel processes requiring bipolar membranes: e.g., producing on-site acid and base from desalination brines, concentrating gases from waste streams (like recovering of ammonia and capturing of carbon dioxide), storing energy in water-based acid-base flow batteries, and producing hydrogen directly from seawater. In the transition towards a circular sustainable economy, these processes are of utmost importance and play a pivotal role.

This PhD project is driven by the pressing need for innovative solutions to meet current and future demands for bipolar membranes in the transition towards a circular society. Our focus lies in developing a novel electrospun bipolar membrane capable of significantly enhancing water dissociation rates. Our aim is to engineer a membrane chemistry and structure that optimizes water transport and dissociation, particularly at the 3D junctions, thereby achieving a tenfold increase in the dissociation rate of water molecules into protons and hydroxyl ions for above mentioned applications.

Research challenges
A bipolar membrane consists of an anion and a cation exchange layer put together with catalyst particles at the interface. Research in bipolar membrane development thus encounters several challenges and research gaps. These include optimal structuring of the 3D junction at the interface of the two layers and its integration with the catalyst, identifying suitable water dissociation catalysts and refining the chemistry of both the anion and cation exchange layers. Moreover, production rates of electrospinning need to be increased. Additionally, optimizing hot-pressing conditions and layer thickness are critical.

Your assignment
In this PhD project, you will develop novel electrospun bipolar membranes with the capability to operate at elevated current densities. You will use specialized electrospinning setups available at Wetsus and TU/e, one featuring three independent electrospinning/electrospraying positions under controlled environmental conditions and another one for production at larger scale. Scalability is a leading principle: the concepts to be developed must be easy to scale up to obtain large production volumes at high speed to guarantee large scale commercial application. For characterization of the membranes, you will involve methods like Scanning Electron Microscopy and RAMAN spectroscopy. For evaluating the performance of the prototypes, you will use electrochemical methods like Chronopotentiometry at variable current densities and Electrochemical Impedance Spectroscopy. Also, you will assess membrane aging through monitoring voltage under constant current over a prolonged period of time. Ultimately, bipolar membrane performance in setups for electrodialysis, flow cells, acid and base production and water treatment can be determined. Autopsy of aged membranes will further elucidate aging mechanisms, aiming to enhance membrane longevity. The comprehensive approach aims to the ultimate outcome of your PhD project: advancing on production scalability, on membrane performance, and on membrane durability.

Your Profile
As a suitable candidate, you have (or soon obtain) a Master of Science background in polymer science, chemical technology, or physical chemistry, with expertise in electrochemistry. Practical skills are essential, alongside the ability to work collaboratively in a team and a keenness to learn new techniques. A proactive attitude towards innovation and problem-solving is crucial for advancing membrane technology.

Keywords: Electrospinning, bipolar membranes, membrane science and technology, membrane manufacturing

Supervisory Team: University promotor and co-promotor: Prof.dr.ir. Kitty Nijmeijer (Eindhoven University of Technology), Dr. Zandrie Borneman (Eindhoven University of Technology)
Wetsus supervisor: Dr. Michel Saakes (Wetsus)

Project partners: Sustainable Carbon Cycle

A meaningful job in a dynamic and ambitious university, in an interdisciplinary setting and within an international network. You will work on a beautiful, green campus within walking distance of the central train station. In addition, we offer you:

• Full-time employment for four years, with an intermediate evaluation (go/no-go) after nine months. You will spend 10% of your employment on teaching tasks.
• Salary and benefits (such as a pension scheme, paid pregnancy and maternity leave, partially paid parental leave) in accordance with the Collective Labour Agreement for Dutch Universities, scale P (min. €2,770 max. €3,539).
• A year-end bonus of 8.3% and annual vacation pay of 8%.
• High-quality training programs and other support to grow into a self-aware, autonomous scientific researcher. At TU/e we challenge you to take charge of your own learning process.
• An excellent technical infrastructure, on-campus children's day care and sports facilities.
• An allowance for commuting, working from home and internet costs.
• A Staff Immigration Team and a tax compensation scheme (the 30% facility) for international candidates.