Spontaneous Kinking of Microdomain Structures in Block Copolymer Film By Solution Cast Using Selective Solvent

We report experimental findings of spontaneous perpendicular orientation and successive kinking microdomains in film specimens block copolymer by solution cast using selective solvent. These phenomena were firstly found out our experiments. It is notable that only conducting a straightforward sophisticated to obtain cylindrical lamellar because mainly reported methods utilize application external fields such as electric, magnetic, or temperature gradient field. The key point this method exists utilization solvent which possesses different degrees solubility for two respective components copolymer. specimen used polystyrene-block-poly(ethylene-butylene)-block-polystyrene triblock solvents n-heptane, dichloromethane, toluene, are selectively good PEB (poly(ethylene-butylene)), PS (polystyrene), PS, respectively. Furthermore, mixtures n-heptane dichloromethane more precise control the degree selectivity. To analyze nano structures as-cast annealed specimens, transmission electron microscopy two-dimensional small-angle X-ray scattering (2d-SAXS) measurements conducted at room temperature. As result, edge-view 2d-SAXS pattern relevant was obtained toluene cast. explain mechanism, schematic illustrations presented with idea parallel cylinders lamellae, during further evaporation.