Amine-Containing Block Copolymers for the Bottom-Up Preparation of Functional Porous Membranes

The remarkable ability of biological systems to specifically recognize, sort, and process molecules encourages the development of novel bio-inspired membranes and interfaces. Herein, we focus on the functionalization of amphiphilic polystyrene- block -poly(2-hydroxyethyl methacrylate) (PS- b -PHEMA) with the amino acid glycine yielding polar block segments with primary amine functionalities. Excellent control over the tailored block copolymer (BCP) synthesis and functionalization is proven by size exclusion chromatography (SEC), 1 H solution NMR, and 15 N solid state NMR spectroscopy. For the first time, BCPs containing primary amines were used for the self-assembly and non-solvent induced phase separation (SNIPS) process for the preparation of isoporous and integral asymmetric membranes. Hexagonally arranged open pores with diameters of 19 nm were obtained as shown by scanning electron microscopy (SEM), atomic force microscopy (AFM), and pH-dependent water flux measurements. Additionally, the primary amine was subjected to convenient postmodification protocols. For instance, (fluorescent) dye molecules could be easily incorporated into the membrane structure, and peptide synthesis on the inner pore wall of the membrane could be accomplished. These novel and tailored porous materials will pave the way to a new generation of BCP membranes containing bio-inspired moieties and functionalities at the interfaces.