title: Silsesquioxane/polyamine nanoparticle-templated formation of star- or raspberry-like silica nanoparticles.
abstract: Silica is an important mineral in biology and technology, and many protocols have been developed for the synthesis of complex silica architectures. The current report shows that silsesquioxane nanoparticles carrying polymer arms on their surface are efficient templates for the fabrication of silica particles with a star- or raspberry-like morphology. The shape of the resulting particles depends on the chemistry of the polymer arms. With poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) arms, spherical particles with a less electron dense core form. With poly{[2-(methacryloyloxy)ethyl] trimethylammonium iodide} (PMETAI), star- or raspberry-like particles form. Electron microscopy, electron tomography, and small-angle X-ray scattering show that the resulting silica particles have a complex structure, where a silsequioxane nanoparticle carrying the polymer arms is in the center. Next is a region that is polymer-rich. The outermost region of the particle is a silica layer, where the outer parts of the polymer arms are embedded. Time-resolved zeta-potential and pH measurements, dynamic light scattering, and electron microscopy reveal that silica formation proceeds differently if PDMAEMA is exchanged for PMETAI.
authors.affiliation: Department of Chemistry, University of Basel, CH-4056 Basel.
authors.forename: Lucy
authors.initials: L
authors.lastname: Kind
authors.forename: Felix A
authors.initials: FA
authors.lastname: Plamper
authors.forename: Ronald
authors.initials: R
authors.lastname: Göbel
authors.forename: Alexandre
authors.initials: A
authors.lastname: Mantion
authors.forename: Axel H E
authors.initials: AH
authors.lastname: Müller
authors.forename: Uwe
authors.initials: U
authors.lastname: Pieles
authors.forename: Andreas
authors.initials: A
authors.lastname: Taubert
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Meier
mesh_terms: D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D017646:Organosilicon Compounds / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D017646:Organosilicon Compounds; D011073:Polyamines