| The research presented in this dissertation deals with various aspects of directed-assembly of cylinder-forming block copolymer thin films: the alignment of polymer domains using graphoexpitaxy and electric fields, the defect mobility and fluctuations at elevated temperatures, the influence of incommensurability on the alignment and using the block copolymer templates to align nanoparticles.;In chapter 2 and 3, we investigated the mobility and annihilation of defects in block copolymer thin films on flat substrates and nano-patterned trenches. The high-temperature time-lapse Atomic Force Microscopy (AFM) used in this experiment enables us to probe real-time and real-space defect movement for the first time. The evolution pathways, mobility and activation energies have been determined for different defect configurations.;In Chapter 4, the alignment of block copolymer domains in tapered width channels has been studied. Confined polymer chains undergo elastic deformation to satisfy the channel width constraint and narrow end of the channel imparts a stronger directing field on the alignment of block copolymer domains.;Electric fields have been introduced to align block copolymer domains in Chapter 5. The domain orientation can be easily switched with the design of electrode quardrupole. Finally, in Chapter 6, corrugated block copolymer templates formed by selectively swelling one of the blocks are used to align nanorods. End-to-end arrangement of nanorods is also achieved in laterally aligned block copolymer grooves. |
