Microphase separation drives structure formation in block copolymers and is a promising and convenient way for the preparation of well-defined hierarchically ordered materials. Moreover, such polymers can be addressable by external triggers representing a unique class of building blocks for the generation of novel materials. Another fabrication technique for porous materials is the ion track etching method which allows the control over size, shape and number density of parallel oriented nanopores. In this work, one focus is the preparation of flexible integral asymmetric membranes which feature an isoporous layer (see figure, left) by exploiting the self-assembly in the non-solvent induced phase separation (SNIPS) process of amphiphilic block copolymers, e.g. polystyrene-block-poly(2-hydroxyethylmethacrylat) (PS-b-PHEMA). These materials possess a large number of hydroxyl-functionalities in the pore inner surface. Another focus of this work is the functionalization of track-etched polyethylene terephthalate (PET) membranes with stochastically distributed nanopores (see figure). After etching, the surface features carboxylic or alcohol functionalities that were coated with silica by means of atomic layer deposition. It is shown how these porous materials are designed and functionalized via polymerization protocols such as atomic transfer radical polymerization (ATRP) with ferrocene or by grafting from/to approach with ferrocene-containing polymers. By taking advantage of the ferrocene/ferrocenium oxidation cycles such functionalized polymers can expand or collapse. Redox-responsive porous materials are expected to selectively control the water-flux as well as the ion-selective permeation through the membrane.

Functionalization of porous polymer materials with redox-responsive moieties

254th National Meeting (2017)

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