Thickness dependent optical characteristics of 1D block copolymers

Abstract

Block copolymers (BCPs) have been investigated for fabricating functional nanomaterials due to their properties of self-assembly. We prepared polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) lamellar films which is hydrophobic block-hydrophilic polyelectrolyte block polymer have 57 kg/mol-b-57kg/mol. The lamellar stacks are obtained by exposing the spin coated film under chloroform. The P2VP blocks were then quaternized and crosslinked to various extents using 5wt% of iodomethane. The quarternized films with thickness varied from 0.43 mu;m (446 nm absorption maximum) to 0.25 μm (478 nm absorption maximum). The band shift as well as scattering around 400 nm clearly suggests that the each layer thickness changed accompanying with the roughness of the layer interfaces.