Vertical Lamellae Formed by Two-Step Annealing of a Rod-Coil Liquid Crystalline Block Copolymer Thin Film
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acsnano.9b09702.pdf
Description
Published version
Size
7.74 MB
Format
Adobe PDF
Checksum (MD5)
63cedb380bd3b2cfedc1e6c57640816b
Author(s)
Lee, Sangho
Cheng, Li-Chen
Ross, Caroline A.
Date Issued
March 2020
Journal
ACS nano
Publisher
American Chemical Society (ACS)
Citation
Shi, Ling-Ying et al. “Vertical Lamellae Formed by Two-Step Annealing of a Rod-Coil Liquid Crystalline Block Copolymer Thin Film” ACS nano, vol.14 , no. 4, 2020, pp. 4289-4297 © 2020 The Author(s)
Version
Final published version
Abstract
Silicon-containing block copolymer thin films with high interaction parameter and etch contrast are ideal candidates to generate robust nanotemplates for advanced nanofabrication, but they typically form in-plane oriented microdomains as a result of the dissimilar surface energies of the blocks. Here, we describe a two-step annealing method to produce vertically aligned lamellar structures in thin film of a silicon-containing rod-coil thermotropic liquid crystalline block copolymer. The rod-coil block copolymer with the volume fraction of the Si-containing block of 0.22 presents an asymmetrical lamellar structure in which the rod block forms a hexatic columnar nematic liquid crystalline phase. A solvent vapor annealing step first produces well-ordered in-plane cylinders of the Si-containing block, then a subsequent thermal annealing promotes the phase transition from in-plane cylinders to vertical lamellae. The pathways of the order-order transition were examined by microscopy and in situ using grazing incidence small-angle X-ray scattering and wide-angle X-ray scattering.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1021/acsnano.9b09702
