Chemical & Biomolecular Engineering - Events of Interest

Stimuli-Responsive Polymer Architectures

Prof. Dr.-Ing. Markus Gallei

Polymer Chemistry, Universität des Saarlandes

Scientific Director of Saarene, Saarland Center for Energy Materials and Sustainability

Over the last decade, stimuli-responsive polymers have attracted considerable attention for a range

of important applications.1,2 Such polymers are capable of changing their conformation and solubility,

or they can even break or form covalent bonds upon a change of temperature or pH value, upon light

irradiation, by using electrochemical stimuli, or by the presence of an electrical or magnetic field, or by

combinations thereof.3-6 The presentation will focus on two polymer classes, which contain at least one

selectively addressable segment, either chemically or physically: (i) the microphase separation of block

copolymers is exploited in the bulk state but also using the non-solvent induced phase separation

(NIPS) process for the preparation of nanoporous and switchable structures to gain access to flexible

integral asymmetric membranes (Fig. 1, left). The selective isoporous layer can be altered by external

triggers, such as redox chemistry, pH value, or temperature. This switching capability enables efficient,

fully reversible control of water flux, thereby facilitating component separation. (ii) Functional opal

films prepared by using the so-called melt-shear organization technique based on core-shell particles

will be highlighted and discussed in more detail.7,8 Within polymeric opals, external triggers can lead to

fast and reversible changes in their intriguing optical properties, which could be easily processed into

films or 3D-printed into complex objects (Fig. 1, right).9-12 A major benefit of self-assembled polymeric

materials is their inexpensive and convenient preparation, giving a good optical performance. The talk

will provide recent advances in the rational design of functional (porous) switchable materials with

hierarchical architectures. The preparation strategies presented herein will enable numerous

applications in sensing and smart membrane technologies.