August W. Bosse

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Recently there has been a strong interest in the area of defect formation in ordered structures on curved surfaces. Here we explore the closely related topic of self-assembly in thin block copolymer melt films confined to the surface of a sphere. Our study is based on a self-consistent field theory (SCFT) model of block copolymers that is numerically(More)
We report measurements of rapid ordering and preferential alignment in block copolymer films zone annealed below the order-disorder transition temperature. The orientational correlation lengths measured after approximately 5 h above the glass-transition temperature ( approximately 2 microm) were an order of magnitude greater than that obtained under(More)
The use of short chain block copolymer melts as nanostructured templates with sub-10 nm domains is often limited by their low segregation strength ( N). Since increasing molar mass to strengthen segregation also increases the interdomain spacing of block copolymer melts, it is more desirable to increase the Flory-Huggins segment-segment interaction(More)
Motivated by recent zone annealing measurements on stripe-forming block-copolymer films [B. C. Berry, Nano Lett. 7, 2789 (2007)], we study block-copolymer ordering with a spatiotemporally heterogeneous mobility. Specifically, we implement a time- and space-dependent mobility field in the relaxation of a diblock copolymer self-consistent field theory. The(More)
We examine the effects of small-scale, hexagonal, lateral confinement on microdomain ordering in AB diblock copolymer thin films using self-consistent field theory simulations. Specifically, we examine a hexagonal confinement well with side length L approximately equal to five cylindrical microdomain lattice spacings. The commensurability constraints of the(More)
In recent years, there has been increased interest in using microphaseseparated block copolymer thin films as submicrometer/suboptical masks in next generation semiconductor and magnetic media fabrication. With the goals of removing metastable defects in block copolymer thin film simulations and potentially examining equilibrium defect populations, we(More)
We derive an approximate analytic expression for the structure factor of equilibrium, thermal composition fluctuations in an ordered lamellar mesophase. In order to test the validity of the equation, we perform a series of stochastic simulations using an established model of block copolymer ordering and demonstrate that the equation fits the simulation data(More)
We derive an alternative formulation of the free energy of polymer mixing in terms of an osmotic virial expansion. Starting from a generalized free energy of mixing, and the assumption that the internal energy of mixing is analytic in the polymer composition variable, we demonstrate that the free energy of mixing can be represented as an infinite series in(More)
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