title: Self-assembly of multilevel branched rutile-type TiO2 structures via oriented lateral and twin attachment.
abstract: Recent breakthrough of novel hierarchic materials, orchestrated through oriented attachment of crystal subunits, opened questions on what is the mechanism of their self-assembly. Using rutile-type TiO2, synthesized by hydrothermal reaction of Ti(IV)-butoxide in highly acidic aqueous medium, we uncovered the key processes controlling this nonclassical crystallization process. Formation of complex branched mesocrystals of rutile is accomplished by oriented assembly of precipitated fibers along the two low-energy planes, i.e. {110} and {101}, resulting in lateral attachment and twinning. Phase analysis of amorphous material enclosed in pockets between imperfectly assembled rutile fibers clearly shows harmonic ordering resembling that of the adjacent rutile structure. To our understanding this may be the first experimental evidence indicating the presence of electromagnetic force-fields that convey critical structural information through which oriented attachment of nanocrystals is made possible.
authors.affiliation: Department for Nanostructured Materials, Jožef Stefan Institute &Jožef Stefan International Postgraduate School, Jamova cesta 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Vanja
authors.initials: V
authors.lastname: Jordan
authors.affiliation: Slovenian NMR centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.
authors.forename: Uroš
authors.initials: U
authors.lastname: Javornik
authors.affiliation: Slovenian NMR centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Plavec
authors.affiliation: Centre of Excellence for Biosensors, Instrumentation and Process Control, Tovarniška 26, SI-5270 Ajdovščina, Slovenia.
authors.forename: Aleš
authors.initials: A
authors.lastname: Podgornik
authors.affiliation: Department for Nanostructured Materials, Jožef Stefan Institute &Jožef Stefan International Postgraduate School, Jamova cesta 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Rečnik