Structural control in block copolymer-templated nanoporous carbon films

Cooperative assembly of block copolymers (BCPs) with carbonizable polymer precile route to nanoporous carbon materials with well-defined pore size and morphology. There is a subtle balance in reaction kinetics of the carbonizable precursor and ordering of the BCP that controls the extent and length scale over which the ordered structure persists. The use of low molecular weight precursors such as phenolic resin oligomers (resol) enable processing to further order and orient the ordered domains prior to "locking-in" the structure by thermally crosslinking the carbonizable precursor. Processing with solvent, either by exposure to their vapors or use of low volatility solvents in the casting solution, provides one low temperature route to markedly enhance order, but these nanostructures lack long-range orientation. Directional forces through application of a thermal gradient or shear enable large scale orientation of the nanostructures.