Resumo
Non-leachable highly luminescent ordered mesoporous SiO2 spherical particles
Fecha
2010-04-16Registro en:
Nanotechnology. Bristol: Iop Publishing Ltd, v. 21, n. 15, p. 6, 2010.
0957-4484
10.1088/0957-4484/21/15/155603
WOS:000275901500016
2998503841917815
6446047463034654
0000-0003-3286-9440
Autor
Universidade Estadual Paulista (Unesp)
Universidade Federal de Mato Grosso do Sul (UFMS)
CNRS
Resumen
Ordered mesoporous highly luminescent SiO2 particles have been synthesized by spray pyrolysis from solutions containing tetraethylorthosilicate (TEOS) and either cetyltrimethylammonium bromide (CTAB) or the block copolymer Pluronic F-68 as structure-directing agents. Rhodamine B (RhB)-containing samples were prepared by using a simple wet impregnation method followed by the growing of a second silica shell in order to prevent leaching of the dye. The obtained materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder x-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and photoluminescence (PL). Powders with polydisperse spherical grains were obtained displaying an ordered hexagonal array of mesochannels. Luminescence results reveal that RhB molecules have been successfully encapsulated into the channels of mesoporous particles as monomeric species and that a well-defined silica coating hindered dye leaching.