Monolithic Membranes with Designable Pore Geometries and Sizes via Retarded Evaporation of Block Copolymer Supramolecules

We develop a retarded evaporation approach for the alignment of cylinder-forming block copolymer supramolecular monoliths, 3-n-pentadecylphenol (PDP) hydrogen-bonded polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP). A variety of highly ordered, aligned morphologies are produced by varying the dosages of PDP in the supramolecules. Treatment of the aligned supramolecular monoliths in hot ethanol leads to the dissolution of PDP and the selective swelling of P4VP, yielding enlargeable ordered mesopores along the original P4VP/PDP domains. Particularly, from supramolecular monoliths aligned in the morphology of perpendicular cylinders and gyroids, we obtain highly ordered monolithic membranes containing enlarged straight pores and bicontinuous pores, respectively. The straight and gyroidal pores were filled with phenol-formaldehyde resol and further carbonized to produce well-defined carbon nanostructures including nanofibers and reversed gyroids, demonstrating the pore accessibility and the promising templating functionality of the resulted monolithic membranes.