title: Surface-initiated anionic polymerization of [1]silaferrocenophanes for the preparation of colloidal preceramic materials.
abstract: A novel strategy for the preparation of poly(ferrocenylsilane) (PFS) immobilized on the surface of cross-linked polystyrene (PS) nanoparticles is reported. The ferrocene-containing core/shell architectures are shown to be excellent candidates as preceramic polymers yielding spherical ceramic materials consisting of iron silicide (Fe3 Si) and metallic iron after thermal treatment. For this purpose, dimethyl- and hydromethyl[1]silaferrocenophane monomers are polymerized by surface-initiated ring-opening polymerization upon taking advantage of residual vinylic moieties at the PS particle surface. A strategy for selective chain growth from the particle surface is developed without the formation of free PFS homopolymer in solution. The grafted particles are characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). These particles are excellent precursors for ceramics as studied by thermogravimetric analysis (TGA). The composition of the ceramics is studied using X-ray diffraction (XRD) measurements, while the morphology is probed by scanning electron microscopy (SEM) revealing the original spherical shape of the precursor particles. Obtained ceramic materials- predominantly based on iron silicides-show ferromagnetic behavior as investigated by superconducting quantum interference device (SQUID) magnetization measurements at different temperatures.
authors.affiliation: Ernst-Berl Institut für Technische und Makromolekulare Chemie, Technische Universität Darmstadt, Alarich-Weiss-Straße 4, 64287, Darmstadt, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Elbert
authors.forename: Haiko
authors.initials: H
authors.lastname: Didzoleit
authors.forename: Claudia
authors.initials: C
authors.lastname: Fasel
authors.forename: Emanuel
authors.initials: E
authors.lastname: Ionescu
authors.forename: Ralf
authors.initials: R
authors.lastname: Riedel
authors.forename: Bernd
authors.initials: B
authors.lastname: Stühn
authors.forename: Markus
authors.initials: M
authors.lastname: Gallei
mesh_terms: D000838:Anions / Q000737:chemistry; D002516:Ceramics / Q000138:chemical synthesis* / Q000737:chemistry; D003102:Colloids / Q000138:chemical synthesis / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000838:Anions; D003102:Colloids; D009942:Organometallic Compounds; D011108:Polymers
keywords: anionic polymerizations; ceramic precursors; colloids; metallopolymers; stimuli-responsive polymers