Syntheses of mesostructured silica films containing conjugated polymers from tetrahydrofuran-water solutions

Co-self-assembly of mesostructured silica films from solutions of tetrahydrofuran (THF) and water, silica precursor species, and structure-directing Pluronic P123 block-copolymer molecules is reported with and without conjugated polymer guest species. The solution-phase behavior of the ternary THF-water-P123 system guided the selection of nonequilibrium synthesis conditions that allowed highly ordered 2D hexagonal or lamellar mesostructured silica to be prepared. Dilute water, molecules produced in situ by silica condensation were necessary and sufficient to promote P123 self-aggregation into micelles and ultimately liquid crystal-like inorganic-organic mesophases as the THF evaporated. Solid-state two-dimensional C-13{H-1} and Si-29{H-1} NMR characterization of the product film materials revealed highly mobile block copolymer components at room temperature,and preferential interactions of poly(ethylene oxide) moieties with the silica framework at 260 K. Solution processing in THF permitted highly hydrophobic, high molecular weight, conjugated polymers to be directly coassembled within the mesostructured inorganic-organic host matrices', during their formation. The incorporated conjugated polymers exhibited semiconducting properties and enhanced environmental photo-stability that may be exploited in electronic and optoelectronic devices.