Polymeric Nanofibers Prepared from Self-Organized Supramolecules

A facile concept to prepare nano-objects based on self-organizing polymeric supramolecules (also called supramolecular block copolymers) is demonstrated using one particular shape, i.e., nanorods or nanofibers. Cylindrical aggregates consisting of a polystyrene (PS) core and a thin corona of poly(4-vinylpyridine) (P4VP) chains are prepared from P4VP(pentadecylphenol)-block-PS comb-coil supramolecules. Diblock copolymers P4VP-block-PS are stoichiometrically (with respect to the number of pyridine groups) hydrogen-bonded with pentadecylphenol (PDP) amphiphiles to yield P4VP(PDP)-block-PS comb-coil supramolecules. By the selection of appropriate relative block lengths for P4VP(PDP) and PS, a micro-phase-separated cylindrical morphology of PS cylinders inside a P4VP(PDP) matrix is obtained. Subsequent removal of the amphiphiles, accounting for ca. 75% of the matrix material, results in cylinders with a core of PS and a corona of easily adjustable thickness of P4VP. The advantages of the present concept compared to the existing procedures are discussed.