Block Copolymer Supramolecular Assembly beyond Hydrogen Bonding

Supramolecular assemblies of block copolymers (BSAs) with low molecular weight additives require preferential interactions between the additive and one of the blocks. So far, only hydrogen bonds (HB) were explored to obtain BSAs. We report on three novel BSAs of block copolymer PS-block-P4VP with commercially valuable additives of the EDOT family. Two of the additives ((3,4-ethylenedioxythiophene) (EDOT) and 3,4-(2,2-dimethylpropylenedioxy)thiophene (ProDOT)) form the BSAs based on interactions others than HB. The morphology and some properties of the BSAs were studied by means of AFM, FTIR, and spectroscopic ellipsometry. The BSAs reveal cylindrical morphology with periodicity of similar to 30 nm. In thin films the orientation of the cylinders can be switched from perpendicular to parallel by annealing in vapors of a suitable solvent. Extraction with a selective solvent results in porous films with porosity of similar to 15%. These non-HB BSAs were compared with the HB BSA of HMeDOT as well as HABA BSA reported recently. The nature of the non-HB interactions is briefly discussed.