Permselective membranes based on mesoporous hybrid thin films with short polimeric functional groups: mesopores meet brushes

A. CALVO; B. YAMEEN; O. AZZARONI; F. J. WILLIAMS; G. J. A. A. SOLER-ILLIA

Porto de Galinhas, Brazil

Conferencia; XV International Sol-Gel Conference; 2009

Mesoporous oxide thin films (MOTF) derived from the combination of sol-gel and self-assembly techniques present a wealth of potential applications in advanced coatings, sensors, optoelectronic devices or catalysts. Transparent, robust films with high surface area, a great variety of inorganic frameworks, and pore systems with precisely controlled pore size and symmetry are now routinely produced by the Evaporation Induced Self Assembly (EISA) pathway. MOTF constitute indeed a “nanofacility”, where the high control exerted on all the features cited above permits to create chemical systems with confined functions, either within the walls or the pores. The possibility of adding organic groups to the surface, either as short dangling groups or brush polymers permits to regulate molecule flux within the pore systems. Control of chemical reactivity within pore systems permits to include nanoparticles, imparting new optical and catalytic properties to the ensemble. In addition, the formation of multilayer films made up of stacked MOTF permit to build complex nanosystems presenting different chemical reactivity in one dimension, and thus the possibility of precisely locating chemical functions or nanospecies with a given property. In this presentation, we will discuss relevant examples in which organic functions (molecules, brush polymers) or metallic nanoparticles are included within MOTF, leading to novel and tailorable optical or molecule/ion filtering properties. This is possible thanks to a precise control of the formation and surface modification of a mesoporous framework by using a wide palette of sol-gel techniques.