Topology Effect on Order-Disorder Transition of High-χ Block Copolymers.

This work aims to systematically examine the topology effect on the self-assembly of block copolymers. Compositionally, symmetric polystyrene--polydimethylsiloxane block copolymers (BCPs) with different chain topologies (diblock, three-arm star-block, and four-arm star-block) and various molecular weights are synthesized. These purposely designed block copolymers are used as a model system to investigate the topology effect on order-to-disorder transition temperature ( ) by temperature-resolved small-angle X-ray scattering experiments.

Sequential Self-Assembly of Polystyrene--Polydimethylsiloxane for 3D Nanopatterning Solvent Annealing.

This study aims to develop a strategy for the fabrication of multilayer nanopatterns through sequential self-assembly of lamella-forming polystyrene--polydimethylsiloxane (PS--PDMS) block copolymer (BCP) from solvent annealing. By simply tuning the solvent selectivity, a variety of self-assembled BCP thin-film morphologies, including hexagonal perforated lamellae (HPL), parallel cylinders, and spheres, can be obtained from single-composition PS--PDMS. By taking advantage of reactive ion etching (RIE), topographic SiO monoliths with well-ordered arrays of hexagonally packed holes, parallel lines, and hexagonally packed dots can be formed.