Artigo
Effects of self-assembly process of latex spheres on the final topology of macroporous silica
Fecha
2005-11-15Registro en:
Journal of Colloid and Interface Science. San Diego: Academic Press Inc. Elsevier B.V., v. 291, n. 2, p. 448-464, 2005.
0021-9797
10.1016/j.jcis.2005.05.016
WOS:000232815500017
6446047463034654
2998503841917815
5584298681870865
0000-0002-8356-8093
Autor
Fac COC
Universidade Estadual Paulista (Unesp)
Resumen
This paper surveys the topology of macroporous silica prepared using latex templates covering the submicrometric range (0.1-0.7 mu m). The behavior of latex spheres in aqueous dispersion has been analyzed by dynamic light scattering (DLS) measurement indicating the most appropriate conditions to form well-defined cubic arrays. The optical behavior of latex spheres has been analyzed by transmittance and reflectance measurements in order to determine their diameter and filling factor when they were assembled in bidimensional arrays. Macroscopic templates have been obtained by a centrifugation process and their crystalline ordering has been confirmed by porosimetry and scanning electron microscopy. These self-assembled structures have been used to produce macroporous silica, whose final topology depends on the pore size distribution of the original template. It has been seen that latex spheres are ordered in a predominant fcc arrangement with slipping of tetragonal pores due to the action of attractive electrostatic interactions. The main effect is to change the spherical shape of voids in macroporous silica into a hexagonal configuration with possible applications to fabricate photonic devices with novel optical properties. (c) 2005 Elsevier B.V. All rights reserved.