Mesoporous silica templated by polyion complex micelles: A versatile approach for controlling the mesostructure

摘要

The possibility to structure silica materials using polyion complex (PIC) micelles of poly-L-lysine (PLL) and poly(ethylene oxide)-b-poly(acrylic acid) (PEO-b-PAA) as novel structure directing agents was evidenced. More importantly the potential of such polyion complexes to act as versatile systems allowing an easy control of the silica mesostructure was revealed, thus providing materials with adjustable physicochemical properties. Different mesostructures (lamellar, wormlike) and morphologies (bulk, nano particles) were obtained by simply varying the initial composition of the reaction medium, namely the ratio between the two polymers, the amount of silica relative to the polymers and the overall mass concentration, which in turn governed the chemical composition of the obtained hybrid organic/inorganic materials. All the processing parameters-induced mesostructural variations were rationalized with respect to the chemical compositions of the resulting hybrid materials, which were discussed based on competing chemical equilibria between species responsible for the mesostructuring; the results were interpreted in terms of interfacial curvature changes. (C) 2016 Elsevier Inc. All rights reserved.