Thin films with densely, regularly packed nanochannels: Preparation, characterization, and applications

A poly(tert-butyl acrylate)-block-poly(2-cinnamoylethyl methacrylate), PtBA-b-PCEMA, sample was synthesized and characterized. After annealing at 105 +/- 2 degrees C, the PtBA block formed densely packed cylinders inside the PCEMA matrix. Thin films of the diblock were obtained by microtomy. After PCEMA photo-cross-linking the tert-butyl groups of PtBA were hydrolyzed, leaving poly(acrylic acid) chains in the loosely packed nanometer-sized cylinders. The permeability of water across such films varied by several orders of magnitude, depending on the pH of the aqueous medium or the types of cations in it. The possibility of using such nanochannels as templates for making further nanostructures was tested by filling the nanochannels with CdS or Fe2O3 nanoparticles.