title: Anisotropic self-organization of hybrid silica based xerogels containing bridged positively charged 1,4-diazoniabicycle[2.2.2]octane chloride group.
abstract: Anisotropic self-organized hybrid silica based xerogels were obtained. The ordered structure was imposed by the double charged 1,4-diazoniabicycle[2.2.2]octane chloride group bonded in a bridged way. This was confirmed by the presence of well defined X-ray diffraction peaks corresponding to an interplanar distance with the same length estimated for the organic bridged groups. The material was characterized by elemental analysis using CHN technique and the chloride ion was analyzed by a potentiometric titration. (13)C and (29)Si CP MAS solid state NMR spectroscopy and thermogravimetric analysis were also performed. The material that can be obtained in the form of powders and transparent monoliths or films, is thermally stable up to 260 degrees C and the samples with high organic content presented birefringence properties.
authors.affiliation: LSS, Instituto de Química, UFRGS, CP 15003, 91501-970 Porto Alegre, RS, Brazil.
authors.forename: Leliz T
authors.initials: LT
authors.lastname: Arenas
authors.forename: Adriana C
authors.initials: AC
authors.lastname: Pinheiro
authors.forename: Juliana D
authors.initials: JD
authors.lastname: Ferreira
authors.forename: Paolo R
authors.initials: PR
authors.lastname: Livotto
authors.forename: Vitor P
authors.initials: VP
authors.lastname: Pereira
authors.forename: Márcia R
authors.initials: MR
authors.lastname: Gallas
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Gushikem
authors.forename: Tania M H
authors.initials: TM
authors.lastname: Costa
authors.forename: Edilson V
authors.initials: EV
authors.lastname: Benvenutti