title: Superhelices of poly[2-(acetoacetoxy)ethyl methacrylate].
abstract: Poly[2-(acetoacetoxy)ethyl methacrylate] (PAEMA) homopolymers were found to self-assemble into hierarchical superstructures, that is, double-stranded helical tubes of either screw sense (scanning force microscopy). Both the diameter and the pitch of the superhelices are approximately 12 nm, and their length is 200-500 nm. It is proposed that PAEMA chains first organize into ribbons, the width of which determines the pitch of the helix, and then coil up into the helical superstructure. The formation of these structures is driven by the establishment of hydrogen-bridging interactions between adjacent acetoacetoxy groups (NMR and dielectric relaxation spectroscopy) and compensation of dipole moments.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Colloid Department, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany. schlaad@mpikg-golm.mpg.de
authors.forename: Helmut
authors.initials: H
authors.lastname: Schlaad
authors.forename: Theodora
authors.initials: T
authors.lastname: Krasia
authors.forename: Markus
authors.initials: M
authors.lastname: Antonietti
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D008853:Microscopy; D008968:Molecular Conformation; D011109:Polymethacrylic Acids / Q000737:chemistry*
chemical_list: D011109:Polymethacrylic Acids; C030613:polymethacrylic acid