ISBN 9783843957922

978-3-8439-5792-2, Reihe Mikrosystemtechnik

Christian Piesold
Synthesis and investigation of novel sulfonated poly(phenylene sulfone)s

267 Seiten, Dissertation Albert-Ludwigs-Universität Freiburg im Breisgau (2026), Softcover, B5

Zusammenfassung / Abstract

Proton exchange membrane water electrolysis is one of the most promising technologies to facilitate large scale generation of green hydrogen from renewable electricity sources. Hydrogen as a chemical energy carrier is an important cornerstone in Europe’s plan to become independent of fossil fuels, both for environmental and geopolitical reasons. The proton exchange membrane is the center piece of this technology. To this day these membranes typically consist of fluorinated materials such as Nafion™. These materials have dominated the field for decades, due to their unique combination of high ionic conductivity, chemical resilience and processability. Unfortunately, these materials do not come without their downsides and environmental concerns as well as softening issues at high temperature operation have prompted the search for alternatives. In the class of hydrocarbon-based polymer electrolytes a great variety of interesting candidates can be found.

Sulfonated poly(phenylene sulfone)s are one of the most promising candidates among hydrocarbon-based polymer electrolytes. Their high ionic conductivity and outstanding chemical stability is a result of their extreme electron-deficient structure and is rare among hydrocarbon polymer electrolytes. While already proven in water electrolysis application, advancements in membrane properties are still necessary to advance the material commercially.

This work is focused on altering the properties of sulfonated poly(phenylene sulfone)s by modifying its structure and incorporating novel fragments into it. Changes in the polymers architecture such as branching and incorporation of blocks were performed to study the effect on the macroscopic properties. Branching lead to very high molecular weights in the resulting polymers and increased membrane strength in the hydrated state, while incorporation of blocks resulted in distinct phase separation between functionalized and non-functionalized polymer domains.