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SELF-ASSEMBLY OF AND USING B4 BENT-CORE LIQUID CRYSTAL MORPHOLOGIES

Liu, Jiao
http://rave.ohiolink.edu/etdc/view?acc_num=kent1649933886519226

Abstract Details

2022, PHD, Kent State University, College of Arts and Sciences / Materials Science Graduate Program.
The coupling between molecular conformation and chirality is a cornerstone in the construction of supramolecular helical structures of small molecules across various length scales. Inspired by biological systems, conformational preselection and control in artificial helical molecules, polymers, and aggregates has guided various applications in optics, photonics, and chiral sorting among others, which are frequently based on an inherent chirality amplification through processes such as templating and self-assembly. The so-called B4 nano- or microfilament phase formed by some bent-shaped molecules is an exemplary case for such chirality amplification across length scales, best illustrated by the formation of distinct nano- or microscopic chiral morphologies controlled by molecular conformation. Introduction of one or more chiral centers in the aliphatic side chains led to the discovery of homochiral helical nanofilament, helical microfilament, and heliconical-layered nanocylinder morphologies. Herein, we demonstrate how a priori calculations of the molecular conformation affected by chiral side chains are used to design bent shaped molecules that self-assemble into chiral nano- and microfilament as well as nanocylinder conglomerates despite the homochiral nature of the molecules. Furthermore, relocation of the chiral center leads to formation of helical as well as flat nanoribbons. Self-consistent data sets from polarized optical as well as scanning and transmission electron microscopy, thin film and solution circular dichroism spectropolarimetry, and synchrotron-based X-ray diffraction experiments support the progressive and predictable change in morphology controlled by structural changes in the chiral side chains. The formation of these morphologies is discussed in light of the diminishing effects of molecular chirality as the chain length increases or as the chiral center is moved away from the core-chain juncture. The type of phase (B1-columnar or B4) and morphology of the nano- or microfilaments generated can further be controlled by sample treatment conditions such as by the cooling rate from the isotropic melt or by the presence of an organic solvent in the ensuing colloidal dispersions. We show that these nanoscale morphologies can then organize into a wealth of two- and three-dimensional shapes and structures ranging from flower blossoms to fiber mats formed by intersecting flat nanoribbons.
Torsten Hegmann (Advisor)
220 p.
Chemistry; Materials Science; Physics
organic helical nano- and microfilaments, molecular conformation, self-assembly, polymorphism, chirality, bent-core liquid crystals, B4 phase

Recommended Citations

Citations

  • Liu, J. (2022). SELF-ASSEMBLY OF AND USING B4 BENT-CORE LIQUID CRYSTAL MORPHOLOGIES [Doctoral dissertation, Kent State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=kent1649933886519226

    APA Style (7th edition)

  • Liu, Jiao. SELF-ASSEMBLY OF AND USING B4 BENT-CORE LIQUID CRYSTAL MORPHOLOGIES . 2022. Kent State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=kent1649933886519226.

    MLA Style (8th edition)

  • Liu, Jiao. "SELF-ASSEMBLY OF AND USING B4 BENT-CORE LIQUID CRYSTAL MORPHOLOGIES ." Doctoral dissertation, Kent State University, 2022. http://rave.ohiolink.edu/etdc/view?acc_num=kent1649933886519226

    Chicago Manual of Style (17th edition)

kent1649933886519226
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© 2022, all rights reserved.
This open access ETD is published by Kent State University and OhioLINK.