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Kawakami C, Hara M, Nagano S, Shimomoto H, Yorimoto Y, Yamada T, Oda S, Ihara E, Seki T. Assembly Structure Formation in Bulk and Ultrathin Films of Poly(substituted methylene) Having an Azobenzene Side Chain. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:11297-11306. [PMID: 38755745 DOI: 10.1021/acs.langmuir.4c01168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
The density of the side chain introduced to a polymer main chain greatly influences the properties and functions of the polymer. This work first reports on the packing structure and properties at an interface of a poly(substituted methylene) where an azobenzene side chain is introduced at every carbon atom in the main chain (C1PAz). The structure and properties are compared with those of a conventional vinyl polymer [poly(methacrylate)] possessing an identical side-chain structure (C2PAz). The packing structure in the bulk state analyzed by X-ray measurements revealed that C1PAz adopts a highly ordered rectangular unit cell structure, whereas C2PAz shows a less ordered lamellar one. Langmuir film balance experiments indicated that both polymers with the trans-azobenzene give essentially the identical 2D side-chain occupying area on water, which agrees well with the smectic B (hexatic packing) model based on the X-ray data. Upon transfer onto a solid substrate, only C1PAz shows a conformational transformation to a spread bilayer-type layer, most probably due to conformational frustration stemming from the crowding of the side chains. This study proposes new insights into the effects of side-chain density on the self-assembly and photoreaction of azobenzene-containing polymers, which are expected to expand the possibilities of polymer design for various applications.
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Affiliation(s)
- Chikara Kawakami
- Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Mitsuo Hara
- Faculty of Engineering and Design, Kagawa University, 2217-20, Hayashi-cho, Takamatsu 761-0396, Japan
| | - Shusaku Nagano
- Department of Chemistry, Rikkyo University, 3-34-1, Nishiikebukuro, Toyoshima-ku, Tokyo 171-8501, Japan
| | - Hiroaki Shimomoto
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 3 Bunko-cho, Matsuyama, Ehime 790-8577, Japan
| | - Yoshitaka Yorimoto
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 3 Bunko-cho, Matsuyama, Ehime 790-8577, Japan
| | - Tomohiro Yamada
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 3 Bunko-cho, Matsuyama, Ehime 790-8577, Japan
| | - Shuichiro Oda
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 3 Bunko-cho, Matsuyama, Ehime 790-8577, Japan
| | - Eiji Ihara
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 3 Bunko-cho, Matsuyama, Ehime 790-8577, Japan
| | - Takahiro Seki
- Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
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Kawakami C, Hara M, Nagano S, Seki T. Induction of Highly Ordered Liquid Crystalline Phase of an Azobenzene Side Chain Polymer by Contact with 4'-Pentyl-4-cyanobiphenyl: An In Situ Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:619-626. [PMID: 36545757 DOI: 10.1021/acs.langmuir.2c02950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The orientation of liquid crystal (LC) molecules is significantly governed by solid interfaces and free surfaces, and a variety of functional materials have been developed using these properties. Although LC materials are already in industrial use, particularly for LC display panels, various studies have been conducted in recent years to better grasp the interface behavior of LC molecules. In this work, we succeeded in in situ observations of induction of higher ordered LC phases at the interface between a side-chain LC azobenzene polymer film with a thickness of ∼400 nm and a low-molecular-mass nematic LC, 4'-pentyl-4-cyanobiphenyl of 35 μm thickness, using small-angle X-ray scattering measurements and polarized optical microscopy. It is revealed that the two different mesogens cooperatively form hybrid higher ordered smectic LC phases probably through weak electron transfer immediately after interfacial contact. The induction process consists of three stages in terms of dynamic structure evolutions. Upon UV irradiation, the hybrid smectic LC structure diminished. This study provides new insights into the behavior of LC molecules near the alignment film on the solid substrate.
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Affiliation(s)
- Chikara Kawakami
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Mitsuo Hara
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Shusaku Nagano
- Department of Chemistry, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501, Japan
| | - Takahiro Seki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
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Hara M, Oguri R, Shingo S, Nagano S, Seki T. Crystallization-Induced Uniform Nanodots Formation of Titanium Dioxide Films. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20210391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Mitsuo Hara
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603
| | - Ryota Oguri
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603
| | - Sarkar Shingo
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603
| | - Shusaku Nagano
- Department of Chemistry, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501
| | - Takahiro Seki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603
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Abstract
AbstractAs a preparation method for organic–inorganic or mesoporous inorganic materials via sol–gel condensation of a metal alkoxide, the combination of lyotropic liquid crystals (LLCs) and sol–gel chemistry is a versatile tool to fabricate various nanostructures. Despite previous investigations into such systems, no attempt has been made to utilize the dynamic switching functions of such nanostructures via the phase transition of LLCs in films. A polysiloxane containing an amine-hydrochloride group and a vinyl group was recently synthesized. By controlling the relative humidity, we achieved the phase transition of LLCs and on-demand UV-curing of LLC phases in the polysiloxane film. We further developed vertically oriented organic–inorganic nanochannels by using π−π interactions between discotic molecules and the substrate surface or the spontaneous vertical alignment of LLC containing azobenzene units.
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HARA M. On-Demand Control of Phase Transition and Orientation of Organic-Inorganic Complex Lyotropic Liquid Crystals. KOBUNSHI RONBUNSHU 2018. [DOI: 10.1295/koron.2018-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mitsuo HARA
- Department of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University
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Seki T. A Wide Array of Photoinduced Motions in Molecular and Macromolecular Assemblies at Interfaces. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20180076] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Takahiro Seki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi 464-8603, Japan
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