INVESTIGADORES
SOLER ILLIA Galo Juan De Avila Arturo
artículos
Título:
Manipulation of Molecular Transport into Mesoporous Silica Thin Films by Infiltration of Polyelectrolytes
Autor/es:
A. BRUNSEN; A. CALVO; F. J. WILLIAMS; G. J. A. A. SOLER-ILLIA; O. AZZARONI
Revista:
LANGMUIR
Editorial:
AMER CHEMICAL SOC
Referencias:
Año: 2011 vol. 27 p. 4328 - 4333
ISSN:
0743-7463
Resumen:
The design of hybrid mesoporous materials incorporating
polymeric assemblies as versatile functional units has become a very
fertile research area offering major opportunities for controlling
molecular transport through interfaces. However, the creation of such
functional materials depends critically on our ability to assemble
polymeric units in a predictable manner within mesopores with
dimensions comparable to the size of the macromolecular blocks
themselves. In this work, we describe for the first time the manipulation
of the molecular transport properties of mesoporous silica thin films by
the direct infiltration of polyelectrolytes into the inner environment of
the 3D porous framework. The hybrid architectures were built up
through the infiltrationelectrostatic assembly of polyallylamine
(PAH) on the mesopore silica walls, and the resulting systems were
studied by a combination of experimental techniques including ellipsoporosimetry,
cyclic voltammetry and X-ray photoelectron spectroscopy,
among others. Our results show that the infiltrationassembly of
PAH alters the intrinsic cation-permselective properties of mesoporous
silica films, rendering them ion-permeable mesochannels and enabling the unrestricted diffusion of cationic and anionic species
through the hybrid interfacial architecture. Contrary to what happens during the electrostatic assembly of PAH on planar silica films
(quantitative charge reversal), the surface charge of the mesoporous walls is completely neutralized upon assembling the cationic
PAH layer (i.e., no charge reversal occurs). We consider this work to have profound implications not only on the molecular design of
multifunctional mesoporous thin films but also on understanding the predominant role of nanoconfinement effects in dictating the
functional properties of polymerinorganic hybrid nanomaterials.