Perpendicular orientation of sub-10 nm channels in polystyrene-b-poly(4-hydroxyl styrene)/PEG oligomer blend thin filmsElectronic supplementary information (ESI) available: Experiment section, AFM images, XPS measurements and tables to show parameters from different methods and electron densities. See DOI: 10.1039/c3nr01491f

Vertically oriented cylinders via the directional coalescence of the spheres embedded in the blend thin films from polystyrene- b -poly(4-hydroxyl styrene) (PS- b -PHS) and PEG induced by solvent annealing were achieved. Removal of PEG water led to the formation of nanochannels throughout the films. The diameter of these channels could be as small as 9 nm which might enhance the applicability of the nano-porous films as size-selective membranes and controllable drug delivery systems for the objects less than 10 nm. Vertically oriented cylinders via the directional coalescence of the spheres embedded in the blend thin films from polystyrene- b -poly(4-hydroxyl styrene) (PS- b -PHS) and PEG induced by solvent annealing were achieved.