Type
Text
Type
Thesis
Advisor
Sokolov, Jonathon | Koga, Tadonori | Venkatesh, TA.
Date
2015-08-01
Keywords
Materials Science
Department
Department of Materials Science and Engineering.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76295
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Block copolymers (BCP) thin films have recently received significant attentions because of their potential " nano" applications, such as nanostructured membranes, nanoparticle templates, photovoltaic cells, low-k dielectrics, and high density data storage media. In this study, I focus on perpendicular cylindrical microdomain structures formed in polystyrene -block-poly (ethylene butylene) block- polystyrene (SEBS) block copolymer ultrathin films (less than 100 nm thick). After prolong high temperature annealing of spin-cast SEBS ultrathin films prepared on silicon substrates, a combined use of atomic force microscopy (AFM) and grazing incident small angle X-ray scattering (GISAXS) experiments proved the formation of highly ordered perpendicular cylindrical microdomain structures within the entire films. However, it was also found that the polymer chains strongly adsorbed on the substrates even after intensive solvent leaching with a good solvent for the polymers, resulting in the formation of irreversibly adsorbed polymer layers. A series of x-ray reflectivity measurements revealed that the thickness of the adsorbed layer increases with increasing annealing time before reaching the " quasiequilibrium" thickness (~ 10 nm in thickness after 123 h). The detailed structures of the adsorbed layers were further characterized by AFM and GISAXS, clarifying the formation process of the adsorbed layer. In addition, I have successfully prepared a variety of adsorbed layers composed of SEBS, polystyrene and polybutadiene homopolymers and studied the possibility to use them an alternative polymer coating materials in place of end-grafted polymer brushes. The experimental results clearly show that the morphologies of the SEBS ultrathin films on top of the adsorbed layer vary with a choice of the adsorbed layer: the PS adsorbed layer is the best to create well-ordered perpendicular cylindrical microdomain structures, while the SEBS adsorbed layer induces parallel cylindrical microdomain orientation instead. Hence, the present study proposes a new way to manipulate the orientation and degree of ordering of microdomain structures in BCP ultrathin films. | 45 pages
Recommended Citation
Di, Xiaoyu, "Effects of polymer adsorbed layers on the formation of perpendicular cylindrical microdomains in polystyrene-block-poly (ethylene butylene) block- polystyrene (SEBS)" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2220.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2220