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  • Free-standing, tartaric acid cross-linked chitosan thin films doped with magnetically aligned NiO-Co3O4 filler were successfully synthesized using facile solution-casting method under externally applied magnetic field. The aligned membranes displayed higher proton conductivity than Nafion-212 when measured by both two-probe and four-probe techniques in zero humid conditions. The membranes also showed excellent thermal, oxidation, and mechanical stability.

    • A. I. Anu Karthi Swaghatha
    • Louis Cindrella
    Original Article
  • A series of aliphatic polycarbonate-based polyurethanes with different content of cyclic structure was synthesized. There were more hydrogen bonds between soft and hard segments formed as the content of cyclic units increased. The mechanical and thermal properties of the environment-friendly polycarbonate-based polyurethanes can be enhanced and controlled by varying the content of the cycloaliphatic structures. These polyurethanes can be considered as high potential materials that can be used in different applications in the future.

    • Yuan-Hsiang Wu
    • Cheng-Chien Wang
    • Chuh-Yung Chen
    Original Article
  • Catalytic ester-interchange reactions allow new sequence information to be written statistically into poly(ester-imide) chains based on NDI (1,4,5,8-naphthalenetetracarboxylic diimide) units. Insertion of the cyclic ester cyclopentadecanolide (“exaltolide”) into an NDI-based homopolymer and quantitative sequence exchange between two different homopoly(ester-imide)s are both catalyzed by di-n-butyl tin(IV) oxide. Emerging sequences from these reactions are identified using pyrene-d10 as a “reader molecule” that binds rapidly and reversibly to the NDI residues, and amplifies the separation of 1H NMR resonances associated with different sequences via cumulative aromatic ring-current shielding.

    • Marcus Knappert
    • Howard M. Colquhoun
    Note Open Access
  • Our retinal prosthesis, referred to as a dye-coupled film, was developed by chemically coupling photoelectric dyes to the surface of a polyethylene film for restoring retinitis pigmentosa. However, the amount of coupled dye decreased during an implantation test in a monkey’s eye. For improving long-term durability, anion exchange from Br to PF6, BF4, and bis(trifluoromethanesulfonyl)imide (TFSI) was conducted. The long-term durabilities of the dye-coupled film–PF6, –TFSI, and –BF4 improved by 637, 215, and 48%, respectively, indicating that the dye-coupled film–PF6 exhibits the best long-term durability.

    • Koichiro Yamashita
    • Tenu Tanaka
    • Tetsuya Uchida
    Original Article
  • A reduction-responsive oligonucleotide was successfully constructed by post-modification of an oligonucleotide with a diazo compound bearing a 4-nitrobenzyl group as a reduction-responsive cleavable moiety. High-performance liquid chromatography and mass spectrometry were used to reveal the introduction of the 4-nitrobenzyl group to the 5′-phosphate group of the oligonucleotide, and the subsequent reduction-triggered recovery of the original oligonucleotide. The protocol used for the preparation of this reduction-responsive oligonucleotide is simple and it will have various applications in the fields of chemical and synthetic biology.

    • Nanami Shirakami
    • Sayuri L. Higashi
    • Masato Ikeda
    Rapid Communication Open Access
  • A microstructured film was fabricated using the breath figure method, and a slippery surface was achieved by infusing silicone oil onto the film. Among the obtained samples, oil-supported pincushion films (oPCF) most efficiently prevented water droplets and microorganisms from adhering to the surfaces. In addition, the adhesion of E. coli and B. subtilis to oPCF was reduced to 7.1 and 13% of that pertaining to PTFE, respectively. These results suggest that our efficient antifouling substrate can ensure human health and environmental safety without the use of any toxic compounds.

    • Ryunosuke Shimura
    • Hiroya Abe
    • Chihiro Inoue
    Original Article
  • Thermoresponsive degradable copolymers and hydrogels were synthesized by radical copolymerization of 2-methylene-1,3-dioxepane (MDO) and N,N-dimethylacrylamide (DMAAm). These prepared materials showed thermoresponsive property through the balance of hydrophobic MDO and hydrophilic DMAAm in the polymer chain. Under alkaline conditions (pH 11.3), these materials degraded and turned into water-soluble oligomers. In addition, the hydrogels self-degraded in PBS due to the decreased pH of the inner hydrogel. The prepared thermoresponsive degradable hydrogels are expected as stimuli-responsive drug delivery carriers and cell culture scaffolds.

    • Syuuhei Komatsu
    • Takuya Sato
    • Akihiko Kikuchi
    Original Article
  • Dissolved polymers directed molecular crystallization behavior under dilute and crowding conditions. Larger poly(ethylene glycol)s (PEGs) accelerated caffeine crystal formation in the dilute regime of PEG solutions, which was attributed to the depletion attraction that promoted caffeine cluster aggregation into crystal nuclei. In the semidilute regime, the crystal formation rate was insensitive to the molecular weight of PEGs. This observation was consistent with polymer blob properties, which govern depletion attraction and maintain a constant size at a given polymer concentration, irrespective of molecular weight in the semidilute regime.

    • Yuuki Hata
    • Xiang Li
    • Takamasa Sakai
    Original Article
  • Poly(ethylene-2,6-naphthalate) (PEN) nanofibers were prepared by carbon dioxide laser supersonic drawing (CLSD). The CLSD method was carried out by irradiating the as-spun PEN fiber with a laser in a low-temperature supersonic jet, which was generated by blowing the air from the fiber supplying orifice into a vacuum chamber. The DSC curve of the PEN nanofibers produced by CLSD showed two melting peaks: 260 °C and 285 °C. The increase in melting temperature is attributed to the supramolecular sequence effect, which is a nanoscale effect.

    • Akihiro Suzuki
    • Yasutaka Oshiro
    Focus Review
  • Biological membranes that tailor their morphology to environmental stimuli are nature’s ultimate smart molecular systems. This focused review describes the design and function of smart biomembrane nanohybrids. Specifically, liposomes and exosomes can be functionalized with inorganic substances and polymers to afford hybridized artificial cell membranes. These membranes have a tailorable morphology and can incorporate functional integral membrane proteins.

    • Yoshihiro Sasaki
    • Kazunari Akiyoshi
    Focus Review
  • The silicone rubber materials with foam/solid alternating multilayered structure have been constructed by combining two methods of the multilayered hot-pressing and supercritical carbon dioxide (SCCO2) foaming. The growth of the cell is restrained by the solid layer, resulting in a decrease of the cell size. In addition, the introduction of the solid layer can effectively improve the mechanical properties of the microcellular silicone rubber foam. The experimental results are analyzed by finite element analysis (FEA).

    • Wenhuan Zhang
    • Zhaoping Deng
    • Tao Liu
    Original Article Open Access
  • Thin film aromatic polyimides were quantitatively analyzed by grazing-incidence X-ray diffraction (GI-XRD), variable-temperature infrared p-polarized multiple-angle resolution spectroscopy (VT-pMAIRS), and spectroscopic ellipsometry (SE) methods. Combining VT-pMAIRS and GI-XRD revealed characteristic heterogeneous structures comprising non-oriented amorphous and oriented liquid-crystalline glass regions. Additionally, SE indicated that the film involved anisotropic-shaped void inducing form-birefringence. Such an excess of birefringence can make it difficult to estimate orientational order using birefringence measurement. This methodology presented here will remarkably contribute to general structural analyses of all intriguing thin-film polymers with characteristic heterogeneity.

    • Ryohei Ishige
    • Kazuyuki Tanaka
    • Shinji Ando
    Original Article
  • This paper reviews our X-ray and neutron scattering experiments on the molecular structure and dynamics of a supramolecular assembly, polyrotaxane (PR) composed of polyethylene glycol (PEG) and α-cyclodextrin (CD). Inclusion complex formation with CDs increases the stiffness of the PEG backbone and restricts the diffusion of the PEG monomers that are covered by or in close proximity to the CD molecules.

    • Koichi Mayumi
    Focus Review
  • A dinuclear Pd(II) complex possessing a cyclic ligand was applied as a coordinative cross-linker of acrylonitrile–butadiene rubber (NBR). Tensile tests revealed that the mechanical properties of the coordinatively cross-linked NBRs were improved compared with those of the original NBR. Increasing the loading amount of the complex enhanced Young’s modulus, tensile strength, tensile strain, and toughness. The cross-linked NBR could be reused with a simple dissolution and drying process, which featured coordinative cross-linking.

    • Koji Yamamoto
    • Hiromitsu Sogawa
    • Toshikazu Takata
    Note
  • We report a novel approach of siloxane bond splitting in organosiloxane using mixture of tris(pentafluorophenyl)borane and dimethyl carbonate. In the first part of this note, depolymerization of polydimethylsiloxane by dimethyl carbonate and with the addition of tris(pentafluorophenyl)borane is studied. Reactions are studied at different concentrations of above-mentioned reagents and temperature while the second part of this note represents theoretical calculation results which explain the mechanism of the depolymerization reaction.

    • Iryna Protsak
    • Volodymyr Gun’ko
    • Volodymyr Turov
    Note
  • Amphiphilic thermoresponsive copolymer bottlebrushes based on methoxy oligo(ethylene glycol) methacrylate (MOEGM) and alkoxy(C12-C14) oligo(ethylene glycol) methacrylate (DOEGM) have been synthesized via RAFT and conventional free-radical polymerization in toluene. In water, these copolymer brushes form flower-like micelles with a hydrophobic core consisting of a polymer backbone and alkyl(C12–C14) groups and poly(ethylene glycol) linear chains and loops forming a hydrophilic shell. The size and aggregation number of the micelles depend on the copolymer composition and chain length, as well as on the synthesis method.

    • Alexey Р. Sivokhin
    • Dmitry V. Orekhov
    • Sergey D. Zaitsev
    Original Article
  • As a surface modifier, poly[oligo(2-ethyl-2-oxazoline) methacrylate] (P[O(Ox)nMA]) with two different degrees of polymerization (n = 7 and 19) of the side chain were mixed into poly(methyl methacrylate) (PMMA). Once the PMMA/P[O(Ox)nMA] films contacted with water, the surface was reorganized due to the migration of P[O(Ox)nMA]. The extent of the surface segregation was more remarkable for P[O(Ox)7MA] than P[O(Ox)19MA] due to the entropic factor, resulting that the fibroblast adhesion on the film were much better suppressed for P[O(Ox)7MA] than P[O(Ox)19MA].

    • Jin-Hyeok Hong
    • Masayasu Totani
    • Keiji Tanaka
    Original Article
  • A facile modification method for a commercial polyethylene membrane separator using a cross-linked single-ion conducting polymer network with a highly delocalized anionic group was developed. A cross-linker, poly(ethylene glycol) diacrylate, and a delocalized anionic monomer, lithium (4-styrenesulfonyl)(trifluoromethanesulfonyl)imide, were used to modify the surface of the polyethylene separator via UV-initiated polymerization. The resulting polymer coating improves the electrolyte wettability and suppresses the diffusion of anionic species across the separator. The effect of the polymer modification of the separator on the electrochemical properties of nonaqueous Li-O2 cells was investigated.

    • Peeranuch Poungsripong
    • Ryota Tamate
    • Makoto Ue
    Original Article
  • Using polymerase chain reaction (PCR)-mediated recombination, we prepared single ribonucleic acid (RNA) chains containing bifunctional RNA sequences involving substrate binding and phosphorescent signaling. The prepared RNAs largely maintained the functionalities of the original aptamers even after bifunctionalization. We demonstrated that the bifunctionalized RNAs can be used as phosphorescent detection probes for the target protein. Therefore, we suggested that the PCR-mediated “one stroke drawing” is a promising strategy for the preparation of RNA detection probes.

    • Iljae Min
    • Takanori Uzawa
    • Yoshihiro Ito
    Original Article
  • Polyrotaxane (PRx) has a necklace-like structure, which exhibits many features (e.g., cyclic molecule slippage) that are not found in other supramolecular structures. In this review, we report that the number of cyclic molecules, the length (molecular weight) of the linear molecules, and the combination of the cyclic molecules and linear molecules in PRx can be precisely controlled to maximize cyclic molecule slippage. In addition, we created a material that quickly recovers its material strength because of the cyclic molecule slippage of PRx.

    • Yuichiro Kobayashi
    Focus Review