Publications by authors named "Jung-Hong Chang"
We have demonstrated the phase behavior of substrate-supported films of a symmetric weakly segregated polystyrene--poly (methyl methacrylate), P(S--MMA), block copolymer and its blends with homopolymer polystyrene (PS) at different compositions. Upon increasing the content of added PS in the blends, lamellae (L), perforated layers (PL), double gyroid (DG) and cylinders (C) are obtained in sequence for films. Among these nanodomains, PL and DG only exist in a narrow region ( denotes the volume fraction of PS).
View Article and Find Full Text PDFArticle Synopsis
- The study investigates how osmotic pressure affects the nanostructures in thin films of a specific block copolymer (P(S-b-MMA)) and its mixtures with polystyrene (PS) homopolymer under different compositions.
- Thin films were created using a method called surface neutralization, where PS mats were treated with UV light and then thermally annealed, leading to the formation of various layer structures, including perpendicular lamellae.
- The removal of the PMMA block through UV exposure and acetic acid rinsing caused osmotic pressure, resulting in surface wrinkling, which was influenced by factors such as film thickness, PS content, and the molecular weight of the block copolymer used.