Langmuir · 2006 · 104 citations · 29 references
Natural SciencesMaterials EngineeringMaterials ScienceOptical MaterialsPolymer ChemistryThin FilmsCoatingsNanoporous MaterialsOptical PolymersPolymer CharacterizationPolymer Thin FilmsSurface ModificationAnti-reflection CoatingsBlock Copolymer Microphase SeparationFilm ThicknessMicrophase SeparationPolymer CoatingsPolymeric CoatingsSponge-like StructureVolume Fraction Effects
We prepared nanoporous films by spin-coating of polystyrene-block-poly(methyl methacrylate) copolymers (PS-b-PMMA) to a glass and irradiating by ultra-violet source followed by selective removal of PMMA blocks with acetic acid. When spin-coated PS-b-PMMA was no longer annealed at high temperatures, microphase separation between two blocks occurred only in the short-range scale. The porous films prepared from PS-b-PMMA with the volume fraction of PMMA block of 0.69 exhibited a spongelike nanoporous structure over the entire film thickness and showed excellent antireflection with a minimum reflection less than 0.1% at visible and near-infrared wavelengths. The observed reflectances were in good agreement with the predictions based on the characteristic matrix theory.
29