Polymeric membranes are used on huge scales for kidney dialysis, wastewater treatment, and drinking water production. However, almost all polymeric membranes are fabricated by a process reliant on the use of unsustainable, expensive, and reprotoxic dipolar aprotic solvents.  The search for greener solvents for membrane production is therefore the subject of current research. An alternative approach, in which water can be utilized as a solvent, is the use of (…) polyelectrolytes, i.e. polymers whose repeating units contain electrolytes. The resulting membranes can be flexibly adapted to the desired application.

In our working group, we are addressing this problem by producing polyelectrolyte membranes using the environmentally friendly aqueous phase separation process. The charge of strong polyelectrolytes is almost independent of the pH value, whereas that of weak polyelectrolytes depends on it. If two oppositely charged polyelectrolytes are dissolved in an aqueous solution with a high concentration of an added salt, a viscous mass is formed from which membranes can be fabricated.

In this work, the aqueous phase separation process should be further characterized by using new weak polyelectrolyte pairs. The project consists of the polyelectrolyte solution preparation, initial preliminary tests with flat membranes and the production of hollow fiber membranes. This parameter study can optional be conducted using a design of experiments (DoE) as a statistical planning tool. The scope of the work package can be adjusted according to the respective work (MA, BA, internship...). The work can be carried out in either in German or English and the start time can be chosen flexibly.

Tasks:

• Preparation of polyelectrolyte solutions
• Membrane fabrication (focus on hollow fiber spinning parameters)
• Membrane characterization

Your Profile:

• Enrolled in Chemistry, Water Science, Process Engineering, or Materials Science
• Interested in membrane fabrication
• Good communication skills

Supervisor(s):

• Rik Mittelstedt, M.Sc.

Are you interested in this topic and do you want to play an active role in the fabrication of new sustainable membranes? Then don’t hesitate to write me an e-mail (rik.mittelstedt[at]uni-due.de) or come visit me in my office.