Superhelices with tunable twisting power directed from supramolecular pairing of focal asymmetry in achiral dendron-jacketed block copolymers

Lin, I-Ping; Chou, Che-Min; Li, Ming‐Chia; Guo, Rong-Hao; Lee, Cheng‐Kuang; Li, Han-Jung; Chiang, Yi Ju; Lin, Yi-Hung; Lee, Yao-Chang; Su, Chun‐Jen; Jeng, U‐Ser; Chuang, Wei‐Tsung

doi:10.1039/c9tc06135e

Cited by 8 publications

(5 citation statements)

References 76 publications

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“…Comparing the microphase separation structures of neat PEO3MEO, PEO4MEO, PEO6MEO, and PEO8MEO, the above results show that only long-chain spacers, such as six and eight methylene groups, enable twist and helical columns to be formed. In general, the microphase separation ability of the BCP is the main factor that dominates the morphology . However, in this case, the final assembly morphology of the TA-doped LC-BCP depends on the results of the microphase separation and chirality-induced competition.…”

Section: Resultsmentioning

confidence: 99%

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Molecular Chirality and Morphological Structural Chirality of Exogenous Chirality-Induced Liquid Crystalline Block Copolymers

et al. 2022

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Chiral expression from the molecular to macromolecular level, as well as aggregates, plays an important role in natural physiological activity. Therefore, understanding the chirality transfer mechanism will provide guidance for the design of new functional chiral materials. Herein, we have systematically investigated the chiral assembly and transfer from the molecular to morphological level in liquid crystalline block copolymers (LC-BCPs) induced by enantiopure tartaric acid (TA) as a chiral source. Both the experimental and theoretical results indicate that the self-organization of the liquid crystal side chains and H-bonding interactions formed between the chiral additive and LC-BCPs are key factors for chiral expression in the self-assembly of LC-BCPs doped with TA. Furthermore, the various morphologies, including particles, spheres, worms, helical cylinders, and spirals, were observed in the LC-BCPs using transmission electron microscopy. The strength of the liquid crystal related to the azobenzene side chain structure has a crucial effect on the morphological transition. This work provides guidance for the design of diverse chiral nanostructures in a chiral molecule-induced achiral polymer system and may establish a fabrication platform for chiral cryptography, optical metamaterials, and other potential applications.

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Section: Resultsmentioning

confidence: 99%

“…In general, the microphase separation ability of the BCP is the main factor that dominates the morphology. 49 However, in this case, the final assembly morphology of the TA-doped LC-BCP depends on the results of the microphase separation and chirality-induced competition.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Molecular Chirality and Morphological Structural Chirality of Exogenous Chirality-Induced Liquid Crystalline Block Copolymers

et al. 2022

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“…A STEM experiment was performed using an FEI Titan microscope under the following conditions: energy of 200 keV; spherical aberration of 58 nm; spot size of 9; illumination semiangle of 25 mrad; camera length of 135 mm; inner high-angle ADF (HAADF) detector angle of 35.9 mrad; and outer HAADF detector angle of 143.6 mrad. Gold particles (30 nm) were deposited on the Polystyrene-b-poly(2-vinylpyridine) (PS-P2VP thin film 25 . Projected images were acquired by rotating an advanced tomography holder (Model 2020; Fischione Instruments) from − 60° to 60° with an angular increment of 2°.…”

Section: Sample Preparation and Data Analysismentioning

confidence: 99%

High-resolution three-dimensional structural determination of unstained double-gyroid block copolymers through scanning transmission electron microscopy

Chen¹,

Yang²,

Chang³

et al. 2023

Sci Rep

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Block copolymer-based multicomponent materials have garnered considerable attention because of tunable properties due to their various constituents. The use of electron tomography through transmission electron microscopy (TEM) for the three-dimensional (3D) imaging of stained block copolymers is an established approach for investigating structure-property relationships. Recently, scanning transmission electron microscopy (STEM) with an annular dark-field (ADF) detector has emerged as a method for the 3D structural analysis of unstained block copolymers. However, because of a lack of electron contrast, only a few low-resolution 3D reconstructions were reported for light elements. Herein, we report the first 3D structural analysis of a 200-nm-thick film composed of unstained double-gyroid block copolymers-polystyrene-b-poly(2-vinylpyridine) (PS-P2VP)-at a resolution of 8.6 nm through spherical aberration Cs-corrected STEM. At this resolution, P2VP molecules can be distinguished from PS molecules in z-contrast 3D reconstructions obtained both experimentally and theoretically. The 3D reconstructions revealed structural differences between stained and unstained specimens.

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“…BCP-based supramolecules are formed through secondary interactions among organic or inorganic guests of specific functionalities and a host block chain of BCPs, revealing unique chemical and physical properties for different applications. The competition between the attractive and repulsive forces between the host polymer and the guest is critical for affecting the dispersion of guests such as homogeneous, localized, or structure-within-structure in the self-assembled morphologies. − For instance, organic surfactants or mesogens could strongly associate polar polymer block chains through ionic or hydrogen bonding forces to form organic nanohybrids, exhibiting light-responsive, conductive, or sensing properties. − To further extend the optoelectronic, catalytical, or sensing properties, inorganic guests are introduced into BCPs to form organic/inorganic nanohybrids. − However, the precise location and the packing geometry of the inorganic additives in the preferential microdomain are hard to be controlled due to the complicated competition between homogeneous and heterogeneous intermolecular interactions, influencing the final performance of the nanohybrid. − …”

Section: Introductionmentioning

confidence: 99%

Propagatable Hierarchical Architectures from Dispersive Fragments to Periodic Nanosheets within Phase-Separated Nanostructures by Controlling Guest–Host Interaction

Lin

Hsu

et al. 2022

Macromolecules

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Nanomaterials with a hierarchical organization of multiple scales are critical for reducing line width in semiconductor manufacturing. We design nanohybrid materials with a hierarchical or homogeneous phase of polyhedral oligomeric silsesquioxane (POSS) nanoparticles by controlling guest–host and guest–guest interactions. The guest POSS nanoparticle with the single-acid-terminated (MA–POSS) or octa-acid-terminated (OMA–POSS) functionality is introduced into a host polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) block copolymer. As the MA–POSS concentration is low, the stronger self-association (guest–guest interaction) between the MA–POSS nanoparticles and the weaker hydrogen bonding force (guest–host interaction) between the P2VP and the MA–POSS result in the formation of dispersive fragments in the chain end of the P2VP block. With increasing MA–POSS concentration, the fragment can grow into a single nanosheet parallel to the lamellar P2VP microdomain and then continuously develop into the periodic tri-nanosheet and quadro-nanosheet. In contrast, introducing the octa-acid-terminated OMA–POSS with enhanced guest–host interaction leads to the homogeneous dispersion of the OMA–POSS cluster in the P2VP microdomain, independent of the OMA–POSS concentration. Moreover, owing to distinct etch contrast among the inorganic POSS and the organic block copolymer, the well-defined line pattern of nanosheets of a few nanometers can be observed. Consequently, the hierarchical structures with the propagatable nanosheet of ∼4 nm or homogeneous dispersion of the POSS nanoparticles within the microphase-separated P2VP microdomain can be well controlled, providing a means of designing nanohybrid materials with distinct distributions of the functional nanoparticles.

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Superhelices with tunable twisting power directed from supramolecular pairing of focal asymmetry in achiral dendron-jacketed block copolymers

Abstract: Focal asymmetry was introduced into achiral dendron-jacketed block copolymers for the formation of hierarchical helical structures via transfer of helical twisting from a primary molecular level to a quaternary structure.

Cited by 8 publications

References 76 publications

Molecular Chirality and Morphological Structural Chirality of Exogenous Chirality-Induced Liquid Crystalline Block Copolymers

Molecular Chirality and Morphological Structural Chirality of Exogenous Chirality-Induced Liquid Crystalline Block Copolymers

High-resolution three-dimensional structural determination of unstained double-gyroid block copolymers through scanning transmission electron microscopy

Propagatable Hierarchical Architectures from Dispersive Fragments to Periodic Nanosheets within Phase-Separated Nanostructures by Controlling Guest–Host Interaction

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