Effect of template and precursor chemistry on pore architectures of triblock copolymer-templated mesoporous carbons

Mesoporous carbons were synthesized by organic-organic self-assembly of triblock copolymer F127 and resorcinol-furfural oligomers. The effects of the mass ratio of F127 to oligomers (F127/RF), reaction time of resorcinol with furfural and furfural/resorcinol ratio (F/R) on pore architecture and phase purity of mesoporous carbons were investigated. Resorcinol-furfural oligomers prefer to mix with hydrophilic poly(ethylene oxide) (PEO) blocks rather than with hydrophobic poly(propylene oxide) (13130) blocks, and thereby cause a swelling of the hydrophilic volume and force the hydrophilic/hydrophobic interface toward low interfacial curvature. As a result, mesostructures including disordered, 3D body-centered cubic (Im3m), 2D hexagonal (p6m), wormlike and mesocellular structures were obtained by increasing the mass ratio of F127/RF. The physiochemical properties of oligomers would determine the quality of interactions between F127 and oligomers, which can affect swelling extent of PEO blocks and the resultant mesostructures. At the same F127/RF ratio, a mesostructure transition from Im3m to p6m to disorder was observed as the degree of polymerization of oligomers increased. This transition is attributed to the decreased thermodynamic driving force for oligomers to mix with PEO blocks. Decreasing F/R ratio could improve the hydrophilic properties of oligomers, which is favor for forming highly ordered mesostructures. (C) 2009 Elsevier Inc. All rights reserved.