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  • The in situ wide-angle (WAXD) and small-angle X-ray scattering (SAXS) measurements have been performed using a synchrotron microbeam technique for the melt-isothermally-growing iPP spherulites. The thus-collected data were found to be classified into three sets of totally different WAXD/SAXS patterns, from which the three different orientation modes of the stacked lamellae and related crystallographic axes were deduced. These structural information allowed us to discuss the growth mechanism of stacked lamellae in the iPP spherulites from the microscopic point of view.

    • Kohji Tashiro
    • Hiroko Yamamoto
    • Yuichi Miyake
    Original Article
  • Water-insoluble micropatterned films were prepared from poly(vinyl alcohol) (PVA) (or ethylene-vinyl alcohol copolymer (EVOH)) and poly(methacrylic acid) (poly(MAAc)). The carboxy groups in poly(MAAc) underwent dehydration reactions with the hydroxy groups in the vinyl alcohol units during heating at 135 °C, which resulted in the introduction of a crosslinked structure with ester bonds into the polymeric network of the micropatterned films. The micropatterns could be peeled off from the films after decomposition and maintained their patterned shapes.

    • Haruki Uchida
    • Wakako Uchiyama
    • Yohei Kotsuchibashi
    Original Article
  • A novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC) was successfully synthesized via a Click reaction between chain-endfunctionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility comparable to that of the corresponding P3HT thin film.

    • Shin Inagaki
    • Kazuhiro Nakabayashi
    • Tomoya Higashihara
    Rapid Communication
  • This study explores the effects of long-term degradation on the viscoelastic properties of viscoelastic liquids using tetra-armed polyethylene glycol (Tetra-PEG) slimes as model material. It aims to enhance control over the viscoelasticity of biomedical materials, like sodium hyaluronate, by introducing specific cleavage sites into the Tetra-PEG slimes to simulate degradation. The study reveals that despite degradation, the slimes maintain a single relaxation mode, offering a method to design viscoelastic liquids with predictable and controllable degradation for biomedical applications.

    • Ryunosuke Kobayashi
    • Mitsuru Naito
    • Takuya Katashima
    Original ArticleOpen Access
  • A new peptide carrier that mimics the basic leucine zipper domain (bZIP) of DNA-binding proteins was designed, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding motif (U = α-aminoisobutyric acid). When mixed with pDNA, (KUA)3-(LU)4 peptide condensed DNA molecules to form nanoparticles. Furthermore, when complexes of the (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), the reporter protein was expressed in plant cells. Thus, (KUA)3-(LU)4 is an efficient carrier of pDNA with high dissociation efficiency.

    • Kota Nomura
    • Seiya Fujita
    • Keiji Numata
    Original ArticleOpen Access
  • In this study, the effects of the polyrotaxane cross-linker concentration and solvent content on elastomer preparation were investigated to obtain elastomers with high toughnesses due to the properties of the polyrotaxane cross-linking agent. If elastomers were prepared in a state in which the slide-ring effect of the polyrotaxane was easily expressed by the concentration of the polyrotaxane cross-linker and the amount of solvent, the elastomers obtained elongated more and were tougher than elastomers made from conventional cross-linkers.

    • Sizhe Liu
    • Tomoya Hayashi
    • Yukikazu Takeoka
    Original Article
  • Postpolymerization modifications of poly(2-methoxyethoxycarbonylmethylene) and poly(2-phenoxyethoxycarbonylmethylene) with mixtures of Me3SiCl and LDA efficiently transformed the alkoxycarbonylmethylene repeating units to ketene silyl acetals to yield a product with up to 93 mol% composition of the latter unit. TBAF-mediated benzylation of the highly silylated polymer with benzyl bromide yielded a polymer containing side chain O (major)- and main chain C (minor)-benzylated units along with the unreacted ketene silyl acetal unit.

    • Hiroaki Shimomoto
    • Shota Inouchi
    • Eiji Ihara
    Original Article
  • This study reports a method that significantly improved the stretchability and damping properties of hydrogels. The innovation is the replacement of traditional short-chain crosslinkers, such as N,N-methylenebis(acrylamide) (MBA), with long-chain crosslinkers. As a result, the molecular chains of the network could slide when stretched, which greatly increased the mechanical elongation and enabled damping by the hydrogel (up to 85%). The maximum elongation reached 21800%, with a toughness of 11.32 MJ m−3. This study provides a new approach for the development of highly stretchable and damping hydrogels.

    • Ming Ge
    • Lidong Zhang
    Original Article
  • Structural changes induced by thermal denaturation and renaturation of a double-helical polysaccharide xanthan in acidic and basic solutions were investigated mainly by light scattering measurements and circular dichroism spectroscopy. In acidic solution, the renatured components were almost the same as those in native components, while small amounts of aggregates and a hairpin structure were produced via denaturation and renaturation processes. In basic solution, the double helices were dissociated upon heating into the single coils, and high molar mass sample produced a hairpin structure after subsequent renaturation.

    • Yasuhiro Matsuda
    • Ryoga Saiki
    • Kazuto Yoshiba
    Original Article
  • The modification of cellulose nanocrystal film using alkyl silane and silane containing tertiary amino groups was performed in a suspension state. Control of the surface structure and functionalization by silane compounds was conducted in the two-stage process. Wettability change property of the silylation-modified CNC triggered by CO2 was demonstrated.

    • Hiroyuki Taniyama
    • Koji Takagi
    Original ArticleOpen Access
  • We examined the adsorption behavior of poly(tert-butyl methacrylate) (PtBMA) and poly(ethyl methacrylate) (PEMA), on a silica surface. Time-evolution of the degree of adsorption γ(t) was evaluated with chip nanocalorimetry. γ(t) revealed a two-step profile for both polymers. At the second stage of adsorption, the slope of γ(t) vs. log t increased as adsorption proceeded; this trend has not been reported for other polymers so far. In addition, atomic force microscopy images of the adsorbed layers revealed corresponding evolutions of the morphologies.

    • Minato Ishihara
    • Tomoya Watanabe
    • Takashi Sasaki
    Original ArticleOpen Access
  • The study on the improvement of the crystallinity of cellulose II by post-treatment with dilute NaOH solution showed that the crystallinity was significantly improved by post-treatment with multiple cycles. The NaOH in an aqueous NaOH solution penetrated only inaccessible surface regions, and cellulose rearrangement occurred only in these regions during post-treatment, improving crystal size. In the second and subsequent posttreatment cycles, cellulose rearrangement occurred only at the inaccessible surfaces expanded during the previous post-treatment cycle, crystallization progressed toward amorphous regions away from the initial crystalline regions.

    • Yuki Kugo
    • Satoshi Nomura
    • Kenji Tajima
    Original Article
  • The fluorophore-modified glucan, TPE-6BG3 adopts an extended, random-coiled form in DMSO, which does not fluoresce. The morphology of the TPE-6BG3 chemosensor changes drastically to a dynamic globule in aqueous media. The dynamic, “induced-fit” globule selectively and sensitively recognizes the medicinally-useful tetrasaccharide, acarbose via glucan-saccharide coaggregation.

    • Hiroki Kurohara
    • Yumiko Hori
    • Gaku Fukuhara
    Original Article
  • Free-standing films of trifluoropropyl-substituted open-cage silsesquioxane-pendant polysiloxane by optimizing sol-gel reaction condition of tris(dimethoxysilyl-ethyl-dimethylsiloxy)-heptatrifluoropropyl-substituted open-cage silsesquioxane. Elastic modulus and the decomposition temperature for 5% weight loss under N2 of the product by polycondensation at 180 °C were significantly higher than that by polycondensation at 50 °C. Significant changes in the UV-vis spectra of the resulting transparent films were hardly observed even after 13 days of UV irradiation.

    • Miku Kosaka
    • Taishi Nakano
    • Kensuke Naka
    Original Article
  • In this short review, we focus on the development of CO2 separation materials consisting of hydrogel particles. The review starts with development of stimuli responsive micro- and nano-gel particles that reversibly absorb CO2 isn response. The next chapter focuses on the development of temperature-responsive hydrogel films consisting of gel particles that reversibly absorb CO2 and the importance of optimizing the pKa values of the amines in the particles. In the end, assembly of defect-free nano-meter-thick CO2 separation membranes consisting of the amine containing hydrogel particles are introduced.

    • Yu Hoshino
    • Shoma Aki
    Focus Review
  • To develop a novel gel catalyst system for a selective reaction, we prepared a variety of gels with homogeneously dispersed crosslinked domain (CD) structures containing iridium complexes with various crosslinking densities. The designed CD gel catalyst catalyzed the N-alkylation of aniline with benzyl alcohol, and the steric effect of the CD structure allowed the selective formation of the secondary amine product by controlling the access of the substrate to the iridium complex.

    • Shohichi Furukawa
    • Hiroki Takeshita
    • Shohei Ida
    Note
  • Photooxidation and fragmentation behaviors of itPP were studied. Photooxidation likely occurred in the amorphous regions of itPP due to the higher oxygen diffusion. Surface deterioration was observed on the UV-exposed itPP films. Pressed films exhibited much denser cracks compared to uniaxially oriented itPP films. Notably, cracks in the uniaxially oriented itPP films were formed along the direction of orientation and decreased with increasing draw ratio. The crystalline structure and oriented molecular chains notably inhibited the photooxidative degradation and fragmentation of the itPP films.

    • Yingjun An
    • Tomoko Kajiwara
    • Atsushi Takahara
    Original Article