book of abstracts - IM2NP

A B S T R A C T S FRIDAY, JULY 2 N A N O S E A 2 0 1 0
appropriate solution, self assembly of the ordered mesostructure in the pores is driven by the evaporation of
the THF from the solution (EISA method). After drying the membranes were withdrawn from the
experimental chamber and their surfaces were cleaned off prior to charecterization. Samples were
characterized by transmission electron microscopy (TEM) and grazing incidence small angle x-ray scattering
(GISAXS) measurements. It was found that the P123 concentration and/or relative humidity conditions
determine the type of mesostructures formed within the pores and the in-pore filling.
Our results demonstrate that high humidity conditions lead to well ordered in-pore mesostructure formation.
Furthermore, increasing the surfactant concentration leads to better filling of the pores and gives rise to the
formation of the desired vertically aligned hexagonal mesostructure within the pores. In addition to the
synthesis conditions our results indicate a strong influence of pore shape on the orientation of the
mesostructure; while round or elliptical pores induce the parallel orientation, less regular or triangular-like
pores induce the desirable vertical orientation.
Figure 1. Schematic drawing of the in-pore mesostructure
a) The horizontal hexagonal phase and b) The vertical
hexagonal phase. c) A top view TEM image of porous
alumina membrane (in black) with an hexagonal
silica/P123 mesostructure filling the pore. In this image
most of the pore is filled with the horizontal hexagonal
phase, but in the center of the pore the vertical orientation
can be seen.
3 – Conclusion
Silica Mesostructures can indeed be formed in the pores of an alumina substrate using the THF-based sol-gel
synthesis and P123 as structure directing agent. Using this synthesis conjugated polymers can be
incorporated at the organic core of the mesostructure. Slower evaporation of the solvent, achieved by high
humidity conditions or higher surfactant concentration, leads to well ordered phases and more vertically
aligned hexagonal phases. Finally, the pore shape was shown to be of great influence on the orientation of inpore
structure.
1. Platschek, B., Petkov, N. & Bein, T. Tuning the Structure and Orientation of Hexagonally Ordered Mesoporous Channels in Anodic
Alumina Membrane Hosts: A 2D Small-Angle X-ray Scattering Study. Angew. Chem. Int. Ed. 45, 1134-1138 (2006).
2. Kirmayer, S., Dovgolevsky, E., Kalina, M., Lakin, E., Cadars, S., Epping, J. D., Fernández-Arteaga, A., Rodríguez-Abreu, C., Chmelka, B.
F.& Frey, G. L. Syntheses of Mesostructured Silica Films Containing Conjugated Polymers from Tetrahydrofuran−Water Solutions. Chem. Mater.
20, 3745-3756 (2008).
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