Self-assembly of a diblock copolymer on a patterned surface with low-energy electron beam.
A pattern was generated by 500 eV electron beam irradiation on benzaldimine monolayer through a grid and subsequent hydrolysis of nonirradiated regions. While we tried to assemble a block copolymer, polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP), on the pattern, we observed that the polarity difference between the two different regions was not right for discriminating the wetting behavior of two blocks of the polymer. Among various modifications of the retrieved amine, it was found that tribromoacetaldehyde was suitable for this end. Surprisingly, treatment of the aldehyde gave a surface preferring the polystyrene block to poly(4-vinylpyridine) block, while the irradiated section favored the latter block. As a result, island morphology was observed on the tribromoacetaldimine region and hole morphology on the irradiated region when the film thickness was 1.3Lo. Contact angle data were consistent with the observed symmetric wetting on the former region and the asymmetric one on the latter.
Kim
Chang Ok
CO
Center for Integrated Molecular Systems, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31 Hyoja-dong, Pohang 790-784, Korea.
Kim
Duk Hoe
DH
Kim
Jung Sook
JS
Park
Joon Won
JW