Photoinduced alignment of nanocylinders by supramolecular cooperative motions

Chemical Resources Laboratory, Tokyo Institute of Technology, R1-11, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Journal of the American Chemical Society (Impact Factor: 11.44). 09/2006; 128(34):11010-1. DOI: 10.1021/ja064148f
Source: PubMed

ABSTRACT A linearly polarized laser beam was used to control nanocylinders self-assembled in an amphiphilic diblock liquid-crystalline copolymer consisting of flexible poly(ethylene oxide) as a hydrophilic block and poly(methacrylate) containing an azobenzene moiety in the side chain as a hydrophobic liquid-crystalline segment. The perfect array of poly(ethylene oxide) nanocylinders was achieved, aligned perpendicularly to the polarization direction of the actinic light by supramolecular cooperative motions between the ordered azobenzene and microphase separation. By the simple and convenient way of photocontrol, the macroscopic parallel patterning of nanocylinders can be easily obtained in an arbitrary area.

  • [Show abstract] [Hide abstract]
    ABSTRACT: We report a strategy for the synthesis of side-on liquid crystalline diblock copolymers by a combination of atom transfer radical polymerization (ATRP) method and a macromolecular azo coupling reaction. The liquid crystalline block, with a terminus suitable for azo coupling reaction, was obtained by ATRP using a synthesized ATRP initiator with the designed functional group and a side-on liquid crystalline monomer. The other block, with a diazonium salt terminus, was obtained by the diazotization of aniline-functionalized PEG. The macromolecular azo coupling reactions between above two polymer blocks were carried out in DMF. The products and intermediates were characterized by GPC, 1H NMR, FT-IR, POM and DSC.
    European Polymer Journal 01/2015; DOI:10.1016/j.eurpolymj.2015.01.022 · 3.24 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Photocontrol of molecular alignment is an exceptionally-intelligent and useful strategy. It enables us to control optical coefficients, peripheral molecular alignments, surface relief structure, and actuation of substances by means of photoirradiation. Azobenzene-containing polymers and functionalized liquid crystalline polymers are well-known photocontrollable materials. In this paper, we introduce recent applications of these materials in the fields of mechanics, self-organized structuring, mass transport, optics, and photonics. The concepts in each application are explained based on the mechanisms of photocontrol. The interesting natures of the photocontrollable materials and the conceptual applications will stimulate novel ideas for future research and development in this field.
    Polymers 03/2012; 4(1). DOI:10.3390/polym4010150 · 2.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Multifunctional semi-interpenetrating polymer network (semi-IPN) constituted of poly(methacrylic acid-co-4phenylazomaleinanil) (MAA-AzoMI) and Pluronic was designed and prepared, which is stabilized by hydrogenbonding interactions between PMAA carboxylic protons and Pluronic ether group. The characteristics of the materials were investigated by FTIR spectra, DSC, DMA and swelling measurements. Because of a large difference in storage modulus below and above the glass transition temperature, the semi-IPN material shows excellent shape memory effect with a recovery ratio of nearly 98%. For this system, the fixing phase is the MAA-AzoMI network, while the reversible phase is the PMAA-Pluronic complex phase. Meanwhile, by introducing azobenzene side group, this supramolecular network is sensitive to UV and visible light. The photoinduced trans → cis isomerization of azobenzene chromophores in the semi-IPN material leads to a transition from hydrophilicity to hydrophobicity of the polymer network. Therefore, UV light can induce a rapid autoloading of drug molecules into the network, and then the bound model molecules can be released under visible light.
    12/2013; 3(4-4):310-318. DOI:10.1166/mex.2013.1128