Browse Articles

  • Review |

    Water desalination through a reverse osmosis (RO) membrane is an important technology for producing pure water from seawater. High-performance membrane materials have been extensively developed because these materials are useful as core elements in practical water separation processes. Bridged polysilsesquioxane (PSQ)-derived membranes are promising candidates for robust RO membranes because they exhibit high thermal stability and chlorine resistance compared to conventional aromatic polyamide membranes. This review reports on our recent studies involving the development of RO membranes based on bridged PSQs.

    • Kazuki Yamamoto
    •  & Joji Ohshita
  • Review |

    There is increasing interest in solid particle-stabilized soft dispersed systems, including bubbles/foams (a gas-in-liquid dispersed system) and liquid marbles (a liquid-in-gas dispersed system). Synthetic colloidal polymer particles are attractive stabilizers, as their hydrophilic–hydrophobic character and surface chemistries can be designed and controlled on demand via polymerization with various functional monomers and post polymer reactions. In this review article, bubbles/foams and liquid marbles stabilized solely with stimulus-responsive polymer particles will be reviewed. The stabilities, structures, and motions of these dispersed systems can be controlled by external stimuli.

    • Syuji Fujii
  • Original Article |

    A triple-helical peptide, H-(Pro-Pro-Gly)10-OH (PPG10) forms complex with NaHeparin in aqueous NaCl at ionic strengths of 20 and 50 mM and at 15 °C. The triple helix of PPG10 in the resulting complex is appreciably stabilized and the melting temperature of the triple helix is considerably higher than without NaHeparin. Analyses of the scattering function of the complex indicate that the molecular shape is substantially different from that of the previously investigated complex, suggesting specific attractive interactions between PPG10 and NaHeparin.

    • Saki Ishida
    • , Tasuku Yoshida
    •  & Ken Terao
  • Focus Review |

    This focus review provides an overview of the formation and functions of surface-segregated monolayers (SSMs) on organic semiconductor films. Careful design of SSM molecules allows the formation of highly ordered surface monolayers with high coverage densities. SSMs can be used to induce changes in the molecular structure and the orientation in the bulk film. SSMs can be used to change the interfacial properties of organic/metal and organic/organic interfaces in various organic electronic devices. These modifications can drastically alter the performance of devices, demonstrating the general importance of interfaces.

    • Keisuke Tajima
  • Original Article |

    Bulk copolymerization of bis(acryloylhydrazine) with N,N-dimethylacrylamide or N,N-diethylacrylamide yielded a transparent cross-linked polymer monolith. Upon treatment with a sodium hypochlorite solution, the cross-linked monolith dissolved in water by de-crosslinking via oxidative degradation of the diacylhydrazine moiety.

    • Nobuhiro Kihara
    • , Kazuya Yanaze
    • , Satoshi Yokoyama
    •  & Moe Kaneko
  • Original Article |

    The nucleating effect of silk fibroin nanodisc on the crystallization behavior of poly(l-lactic acid) (PLLA) was investigated by polarizing optical microscope observations and the differential scanning calorimetry measurements. The experimental results show that the small amount of SFN (only 1%) reduces the induction period and the crystallization half-time while it increases the final degree of crystallinity. It was found that the SFN works as a nucleation agent by increasing the number of nuclei about four times while it does not change the growth rate of spherulites.

    • Amit Kumar Pandey
    • , Vimal Katiyar
    • , Sono Sasaki
    •  & Shinichi Sakurai
  • Original Article |

    Soybean protein isolate (SPI) was bonded to carboxymethyl cellulose (CMC) by a hydrazine bond to prepare SPI-CMC carriers for pesticide applications. AVM/SPI-CMC was obtained by encapsulating avermectin (AVM) with SPI-CMC through thermal denaturation. SPI-CMC could improve the anti-UV performance of AVM and slow down the decomposition rate of AVM. The hydrazone bond and carboxyl groups showed pH responsiveness, which could release drugs rapidly in an acidic environment. Environmentally friendly SPI-CMC could protect and release pesticides continuously, which could improve the efficiency of pesticides.

    • Guanghua Liu
    • , Guanquan Lin
    • , Mingyi Tan
    • , Hongjun Zhou
    • , Huayao Chen
    • , Hua Xu
    •  & Xinhua Zhou
  • Original Article |

    Radical copolymerization of N-substituted maleimides and olefins provides AAB sequence-controlled copolymers by penultimate unit control. In this study, we investigated the steric, resonance, and polar effects of N-substituents on sequence control during copolymerization of various N-substituted maleimides with diisobutene and limonene in chloroform at 60 °C, and concluded that less bulky and more electron-donating substituents effectively induced the penultimate unit effect. We also demonstrated that 2:1 sequence-controlled maleimide copolymers was efficiently produced during radical copolymerization of limonene and N-phenylmaleimides with an electron-donating substituent.

    • Suguru Terada
    •  & Akikazu Matsumoto
  • Original Article |

    We carried out the conventional radical polymerization and reversible addition-fragmentation chain transfer (RAFT) polymerization of di(1-adamantyl) fumarate, bis(3,5-dimethyl-1-adamantyl) fumarate, 1-adamantyl isopropyl fumarate, and 3,5-dimethyl-1-adamantyl isopropyl fumarate. Triblock copolymers consisting of rigid and flexible segments were synthesized by the RAFT polymerization of 2-ethylhexyl acrylate using poly(dialkyl fumarate)s as the macro-chain transfer agents. The excellent thermal stability of the adamantane-containing poly(dialkyl fumarate)s was confirmed by thermogravimetric analysis. The alignment of the rigid poly(dialkyl fumarate)s chains in the solid-state was revealed by X-ray diffraction.

    • Nagisa Tsuji
    • , Yasuhito Suzuki
    •  & Akikazu Matsumoto
  • Focus Review |

    Melanin, a black component of human hair, plays an important role in bright structural colorations in nature. Polydopamine-based artificial melanin particles, inspired by natural melanin and its important role in structural coloration, were used to produce bright structural colors by controlling light reflection and absorption. A variety of structural coloration characteristics have become possible through our investigations of the assembly structure, composition, shape, and application of artificial melanin particles.

    • Michinari Kohri
  • Original Article |

    We developed biobased nanocapsules with enzymatic degradability, which were generated by the layer-by-layer deposition of enzymes and polypeptide over a liposome. Our developed nanocapsules exhibited layer-specific degradation by enzymes, which enables the release of cargo through degradation of the capsule wall as well as accumulation and targeting of nanocapsules through the emergence of surface properties and functionalities such as bone-targeting ability and cell-penetrating ability by unveiling an inner polymer layer.

    • Yuuka Fukui
    • , Hikari Otsuka
    •  & Keiji Fujimoto
  • Original Article |

    The relaxation behavior of random copolymers of diisopropyl fumarate (DiPF) with 1-adamantyl acrylate (AdA) and n-butyl acrylate with various compositions was investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The β relaxation temperature systematically shifted depending on the glass transition temperature of the counterpart copolymers, and the merging of the α and β processes at an intermediate composition was also observed. Thus, the random copolymerization of DiPF and acrylates enables us to fine tune the properties associated with the β relaxation of DiPF segments.

    • Yasuhito Suzuki
    • , Tomoya Tsujimura
    • , Kenji Funamoto
    •  & Akikazu Matsumoto
  • Original Article |

    In this work, MgO2 NPs has been prepared in-situ onto the PVDF matrix to obtain an electroactive and high dielectric composite thin film. A simple, low-cost, solid-state integrated device utilizing the synthesized composite film as the active material is fabricated named as “self-charging photo power bank” (SPPB). The device shows notably high values of energy densities, power densities, and areal capacitances. The device also holds an appreciable long-term recycling capability and has powered electronic gadgets like LEDs and digital table clock.

    • Swagata Roy
    • , Pradip Thakur
    • , Nur Amin Hoque
    • , Arpan Kool
    • , Farha Khatun
    • , Prosenjit Biswas
    • , Biswajoy Bagchi
    •  & Sukhen Das
  • Original Article |

    A highly efficient and environmentally friendly graft polymerization method of methyl methacrylate (MMA) onto cotton was performed using an alkyl zinc initiator in an emulsion system. Using this method, a high-molecular weight (Mw > 106) polymer was grafted onto a cotton fiber with a high graft yield at ambient temperature. The grafted cotton fiber was characterized by FTIR, XRD, TGA, and SEM. Furthermore, the grafted cotton produced by this novel method that involved modifying the surface of the cotton improved its compatibility with a number of organic solvents.

    • Chao Zhao
    • , Hiromu Okada
    •  & Ryuichi Sugimoto
  • Focus Review |

    Novel network structures were applied to crosslinked liquid-crystalline polymers (CLCPs) with photomechanical effects to enhance their performance and function. CLCPs with rearrangeable networks could be reshaped into 3D architectures, in contrast with conventional crosslinked polymers memorizing permanent shapes. The reshaped samples showed various photoinduced motions depending on their initial shapes. Furthermore, interpenetrating polymer networks (IPNs) were developed to improve mechanical and photoresponsive properties of CLCPs. These strategies of controlling the network structures of CLCPs could enable the versatile design of photomobile polymer materials as soft actuators.

    • Toru Ube
  • Original Article |

    The solution-state macromolecular structure of highly 1,6-glucose-branched β-1,3-glucan (6BG3) was elucidated by modifying and complexing with chromophoric reporters. The reporter-modified 6BG3 forms the globule through the random coil-to-globule conversion process. Hybridizing 6BG3 with the polythiophene reporter affords the loose heteroduplex rather than the tight heterotriplex, indicating the formation of the loose homoduplex of 6BG3.

    • Koichi Tamano
    • , Kotoe Nakasha
    • , Mie Iwamoto
    • , Munenori Numata
    • , Toshio Suzuki
    • , Hiroshi Uyama
    •  & Gaku Fukuhara
  • Focus Review |

    Bipolar electropolymerization is a powerful method for wirelessly achieving site-selective anisotropic modification of bipolar electrodes (BPEs) with conducting polymers. In addition, alternating current (AC) bipolar electropolymerization was developed to induce conducting polymer fibers from the terminals of BPEs that propagate parallel to the direction of the electric field. Bipolar electropolymerization is a class of next-generation electropolymerization for obtaining hybrid materials of conducting polymers and conductive objects.

    • Shinsuke Inagi
  • Focus Review |

    Functionalized colloidal particles are fascinating due to their huge range of potential and reported applications. In this focus review, the recent development of a novel “interfacial photoreaction” for the preparation of functional polymer particles is summarized. This approach allows for the direct fabrication of hollow, capsular, non-spherical polymer particles from spherical polymer particles. Furthermore, the ability of this approach to synthesize morphology controlled particles possessing sophisticated functions, such as stimuli responsiveness and molecular recognition capability, was also described in this paper.

    • Yukiya Kitayama
  • Original Article |

    Novel polymer backbones with pendant water-soluble activated esters were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization technique using an acrylamide derivative  bearing an N-hydroxysulfosuccinimide (sulfoNHS) ester as a monomer substrate. To synthesize glycopolymers, the substitution reaction at the sulfoNHS esters on the polymer side chain with an amine-containing saccharide derivative was performed in water. The resulting glycopolymer exhibited a strong interaction with the corresponding lectin in aqueous solution, because the saccharide moieties are multivalent.

    • Sotaro Tsuji
    • , Yuji Aso
    • , Hitomi Ohara
    •  & Tomonari Tanaka
  • Original Article |

    The aggregation states at the surface of spin-coated scaffold films composed of a multifunctional hyperbranched polymer (HBP) were characterized. While perfluorohexylethyl groups were segregated at the surface in air, the surface in water turned to be hydrophilic to minimize the free energy at the outermost region in the film. This surface reorganization was discernably faster and more remarkable for the non-annealed HBP film than for the annealed one. Fibronectin, which promoted the cellular behaviors, was more adsorbed onto the non-annealed HBP film.

    • Hisao Matsuno
    • , Masayasu Totani
    • , Arisa Yamamoto
    • , Masayuki Haraguchi
    • , Masaaki Ozawa
    •  & Keiji Tanaka
  • Focus Review |

    Biodegradable injectable polymer systems exhibiting temperature-triggered formation of chemically cross-linked hydrogel were developed by “mixing strategy”. The mixture of triblock copolymer of poly(ε-caprolactone-co-glycolic acid) and poly(ethylene glycol) (PCGA-b-PEG-b-PCGA, tri-PCG) solution containing hexafunctional polythiol (DPMP) and tri-PCG with terminal acryloyl groups (tri-PCG-Acryl) solution showed temperature-responsible sol–gel transition, and the gelation was irreversible. Duration time of the gel state under physiological condition and physical property of the hydrogel could be controlled by a simple method, just changing the mixing ratio of tri-PCG-Acryl to tri-PCG.

    • Yuichi Ohya
  • Focus Review |

    The effect of polymer design on the interfacial structure and physical properties of polymer films in water based on a poly(vinyl ether) platform with hydrophilic side-chains was examined to construct bioinert interfaces. Hydrophilic surfaces were prepared by utilizing the preferential segregation of a rubbery component in a diblock copolymer film with a glassy component, crosslinking a hydrophilic polymer, and designing an interfacial modifier with a special architecture. Interfacial structure and physical properties controlled by polymer design play important roles in determining bioinert properties.

    • Yukari Oda
  • Original Article |

    We demonstrated the synthesis of fluorescent network polymers through Knoevenagel polycondensation of an (tris(p-formylphenyl)amine) with a phenylenediacetonitrile. The structure based on the electron-donor triphenylamine and electron-acceptor cyano-substituted phenylene-vinylene showed a highly efficient solid-state fluorescence. The model molecule showed a well-defined solvatofluorochromism. Surprisingly, the network polymer linked with para-phenylene-vinylene was only responsive to the solvents with a low dielectric constant and nitrobenzene. The network polymer linked with meta-phenylene-vinylene was responsive to the aromatic solvents only. The characteristic chemoselectivity was observed by the geometric effect of the network structure.

    • Shotaro Hayashi
    • , Shin-ichi Yamamoto
    • , Koji Nishi
    • , Atsushi Asano
    •  & Toshio Koizumi
  • Rapid Communication |

    Thickness changes in polyvinyl acetate thin films, during the temperature cycle across the glass transition temperature (Tg) has been studied in detail. Even after enough thermal treatment done at the high-temperature side of Tg, thickness increase during cooling (negative thermal expansion) is observed. On the other hand, slow thickness decrease is observed with aging at the high-temperature side of Tg. The above interesting phenomena can be well explained by the model considering the presence and changes of the interface layer.

    • Yuwei Liu
    •  & Kenji Sakurai
  • Original Article |

    Gas transport properties of novel polybenzoxazole (PBO)—silica hybrid membranes prepared via sol–gel rand different thermal treatment protocols were investigated. The hybrid membranes showed enhancements of CO2 permeability and CO2/CH4 selectivity with increasing silica content and thermal treatment temperature. The excellent CO2/CH4 separation ability might be achieved by free volume holes crated around polymer/silica interfacial area and increased intermolecular chain distance.

    • Tomoyuki Suzuki
    •  & Azumi Saito
  • Original Article | | open

    Poly(3,4-ethylenedioxythiophene) (PEDOT) was electropolymerized from 50 mm EDOT with 1 mm tetrabutylammonium perchlorate, and acetonitrile. Stable and controllable growth of fractal PEDOT structures was achieved by varying the parameters of the voltage-driven pulsed electropolymerization. A box-counting method was used to determine the fractal dimension fdim, allowing a distinct classification of the different structures and branching. The underlying migration-driven processes enable rapid and directed growth of complex conductive structures.

    • Max Eickenscheidt
    • , Eva Singler
    •  & Thomas Stieglitz
  • Focus Review |

    The development of organic semiconductors (OSCs) applicable to organic field-effect transistors is crucial to printed and flexible electronics. OSCs must meet several prerequisites: 1) high chemical stability, 2) charge carrier mobility exceeding 10 cm2/Vs, 3) appropriate solubility, and 4) high thermal durability. The author and collaborators developed state-of-the-art OSCs based on bent-shaped π-electron cores (π-cores) that satisfy the requirements for printed semiconductor devices. In this focused review, the chemistry and device engineering are introduced with respect to sulfur-bridged V-shaped and N-shaped π-cores among a series of bent-shaped π-cores.

    • Toshihiro Okamoto
  • Original Article |

    Oligomeric siloxanes bearing unconventional fluorescence units, i.e., oxygen, amino, and hydroxyl functionalities, show the intrinsic blue fluorescence that results from oxygen clusters, namely, the CTE mechanism. In addition, intermolecular hydrogen bonds are conducive to the aggregation of the molecular chains and the formation of oxygen clusters.

    • Yuqun Du
    • , Tian Bai
    • , Fan Ding
    • , Hongxia Yan
    • , Yan Zhao
    •  & Weixu Feng
  • Review |

    The cationic comb-type copolymers, which consisted of a polycation backbone grafted with high density of hydrophilic chains, form soluble and soft interpolyelectrolyte complexes with biopolymers and act as an artificial chaperone to assist in the folding of nucleic acids and peptides. The copolymers stabilize DNA duplex, triplex, and quadruplex structures and accelerate strand exchange reactions as well as assist in the folding of functional peptides into the active conformation.

    • Orakan Hanpanich
    •  & Atsushi Maruyama
  • Focus Review |

    Welcoming more participants in a polymer synthesis; recent years, multicomponent reactions (MCRs) have been gradually integrated into synthetic polymer chemistry, which led to a new synthetic toolbox for a range of interdisciplinary applications. In this focus review, this new trend in polymer chemistry has been summarized with including contributions from the author.

    • Ryohei Kakuchi
  • Focus Review | | open

    A method to control on-demand phase transition and alignment of organic–inorganic hybrid containing lyotropic liquid crystals (LLCs) have been developed. By using polysiloxane containing hygroscopicity and photocrosslinking groups, the phase transition of the LLCs can be induced by changes in humidity. The phase-transition behavior of the LLCs in polysiloxane can be suppressed by light irradiation. Further, the author proposed new methods for vertically aligning nanochannels by using surface interaction or the spontaneous vertical-aligned nature, and photopatterning of chromonic dye aggregates.

    • Mitsuo Hara
  • Rapid Communication |

    When the radical polymerization inhibitor 1,4-naphthoquinone (NQ) acts on styrene, the radical capture reaction greatly contributes carbon atoms. In this study, the 1-phenethyl radical, which is a model for the growth radicals of polystyrene, was reacted with NQ using four radical sources, and we identified the reaction product. We confirmed that the same compound was formed upon addition of a small amount of NQ to heated styrene. The frontier orbital energy levels and reaction path energy diagrams were calculated, which provided numerical values to support our experimental results.

    • Takuji Takahashi
    • , Yujirou Ikejiri
    • , Shunichi Himori
    •  & Hiroaki Gotoh
  • Original Article |

    Single-walled carbon nanotubes (SWCNTs) wrapped by poly[2,2’-(2,6-pyridine)-5,5’-bibenzimidazole] (PyPBI) was used for a cathode material of lithium (Li)-oxygen (O2) rechargeable battery. Compared to the Li–O2 cell using nonwrapped SWCNTs, the cell using PyPBI-wrapped SWCNTs showed improved rechargeability during charge–discharge cycles. It was revealed that PyPBI layer facilitated the homogeneous deposition of the discharge products, resulting the smooth reaction during the cycles. The coordination of Li ion onto PyPBI surface might be the key mechanism to realize the homogeneous deposition.

    • Tsuyohiko Fujigaya
    • , Ryota Kanamori
    • , Shinsuke Hirata
    • , Junichi Morita
    • , Masamichi Matsumoto
    • , Masato Eguchi
    • , Il-Chan Jang
    • , Tatsumi Ishihara
    •  & Naotoshi Nakashima
  • Original Article |

    We fabricated the doubly crosslinked gel by stretching the gel during the gelation using tetra-PEG gels. In this gel, two networks having different reference states coexist with and balance each other, influencing Young’s modulus (E) and permanent set (λs). We tuned the time for the stretching imposition on the gels, which influences the 1st network fraction (g1/g0). λs increased with increasing the 1st network fraction, while E had a maximum value against g1/g0, which were explained by the balance between the strain energies of the first and second networks.

    • Takuya Katashima
    • , Ung-il Chung
    •  & Takamasa Sakai
  • Original Article |

    Solutions of PVA in DMSO exhibit higher viscosities and relaxation times compared to solutions of PVA in water and are expected to show higher fiber diameters on electrospinning. Contradictorily, the fiber diameters of electrospun fibers of PVA-DMSO system are lower than that of PVA-water system. This atypical behaviour arises due to pseudostructure formation in DMSO, thereby resulting in an increase in the viscosity and relaxation time but a drop in entanglements resulting in lower fiber diameters. Therefore, a direct correlation between entanglements per chain and fiber diameter was deduced.

    • Deepika Gupta
    • , Manjeet Jassal
    •  & Ashwini K. Agrawal
  • Original Article |

    A melittin-targeting drug carrier was synthesized by the grafting of sodium alginate to an oligopeptide. The melittin-loading onto oligopeptide–alginate nanoparticles at 0.1:1 unit ratio was more than double that onto alginate nanoparticles, suggesting the specific interaction of melittin with the oligopeptide-side chain in the oligopeptide–alginate nanoparticles. More than 80% of Caco-2 cells did not survive under the dose of 2.5 μM melittin-loaded oligopeptide–alginate nanoparticles. The results confirm that the derivation of an oligopeptide-side chain in alginate offers a specific binding site for melittin and effectively works in cancer chemotherapy.

    • Karnthidaporn Wattanakul
    • , Toyoko Imae
    • , Wen-Wei Chang
    • , Chih-Chien Chu
    • , Rina Nakahata
    •  & Shin-ichi Yusa
  • Original Article |

    The new epoxy resins containing degradable acetal linkages were synthesized and used as sizing agents for carbon fibers. Using the degradable sizing agent-applied carbon fibers, the carbon fiber-reinforced plastics (CFRPs) were prepared via laminating prepreg sheets and heating them under pressure. The mechanical properties of the obtained CFRPs were comparable with those of the conventional CFRPs. With the treatment of acidic conditions, the CFRPs with the degradable sizing agents on carbon fiber surface were decomposed and the carbon fibers could be recovered.

    • Ryosuke Aoki
    • , Ayaka Yamaguchi
    • , Tamotsu Hashimoto
    • , Michio Urushisaki
    • , Toshikazu Sakaguchi
    • , Kazumasa Kawabe
    • , Keiichi Kondo
    •  & Hirohumi Iyo
  • Original Article |

    Salt concentration dependence of NaPSS polymacromonomer with 110 monomeric units on each side chain (unfilled circles) cannot be explained by the theory assuming the Debye–Hűckel (DH) potential under the ionic strength outside the brush (dotted line), but can be explained using the DH potential under the ionic strength inside the brush (dashed line) along with the interactions without ionic ones (dot-dashed line).

    • Yusuke Kitagawa
    • , Yusuke Hasegawa
    • , Keita Ide
    •  & Yo Nakamura
  • Original Article |

    The dependence of the fracture surface energy on the stretching velocity for nanoporous polypropylene (PP) sheets was found to consists of static and dynamic components. These terms can be interpreted respectively as plastoelastic and viscoelastic components, as has been shown for soft polyethylene (PE) foams in a previous work. This simple physical interpretation suggests a universal mechanism for the fracture of porous polymer sheets, and could be useful for designing new tough polymers.

    • Takako Tomizawa
    •  & Ko Okumura
  • Focus Review |

    We successfully controlled birefringence and its wavelength dispersion of cellulose esters by choosing different ester substitution groups and sites, controlling the orientation of the crystal, adding low-mass molecules, and forming microscale porous structures. The substitution of two ester groups could provide extraordinary wavelength dispersion of birefringence, which is important for wide-range retardation films. The low-mass additives enhance birefringence values due to the intermolecular orientation correlation with matrix cellulose esters. The anisotropic microporous structure produced by thermoinduced phase separation generates form birefringence, which improves the total birefringence of cellulose esters.

    • Shogo Nobukawa
  • Focus Review |

    To develop highly functional gel materials, the precision construction of the network structure is required. This focus review outlines the structural design of polymer gels by utilizing precision radical polymerization techniques with a focus on the authors’ recent research. In particular, the synthesis of homogeneous networks using precise radical polymerization and the control of the swelling characteristics by tuning the monomer sequence in the gel network chain are described.

    • Shohei Ida
  • Original Article |

    We have synthesized a new nonfullerene electron acceptor, BP(DPPB)4, with a biphenyl core and four diketopyrrolopyrrole arms. After thermal annealing at 120 °C for 10 min, the device based on P3HT:BP(DPPB)4 (2:1) obtained a power conversion efficiency of 1.43% with a high-open-circuit voltage of 1.17 V.

    • Zhitian Liu
    • , Di Zeng
    • , Chengjun Gu
    • , Jing Wen
    • , Xianbao Duan
    • , Qi Zhang
    • , Jie Min
    •  & Xiang Gao
  • Focus Review |

    Categorization of molecular assemblies of primary to quaternary structures is herein proposed with citing typical examples of peptide molecular assemblies for each category. Primary structure; tubes and vesicles, Secondary structure; chimeric morphology, Tertiary structure; phase-separated tubes, Quaternary structure; hierarchical organization of molecular assemblies.

    • Shunsaku Kimura
  • Focus Review |

    This focus review describes that “elastic organic crystals of π-conjugated molecules”. The author developed the field of innovative materials for flexible optoelectronics. Intentional design of intramolecular interaction in π-system furnish the flexible crystals. These crystals show not only elastic bending flexibility and shape tunability but also functionality for mechanical sensors and flexible optical waveguide.

    • Shotaro Hayashi
  • Original Article |

    The birefringent properties of poly(phosphonate)s and poly(thiophosphonate)s possessing various bisphenol structures were investigated. The CR values (orientational birefringence) of the poly(phosphonate)s and the poly(thiophosphonate)s range from −0.3 × 10−9 to + 1.3 × 10−9 Pa−1 and from −0.6 × 10−9 to + 0.8 × 10−9 Pa−1, respectively, which are lower than those of the corresponding bisphenol A-based polymers. The CD values (photoelastic birefringence), which range from + 4.0 × 10−11 to + 4.9 × 10−11 Pa−1, are also lower than those of the corresponding bisphenol A-based polymers.

    • Ryoyu Hifumi
    •  & Ikuyoshi Tomita
  • Note |

    Polar polymers with permanent dipoles such as poly(vinylidene fluoride) (PVDF) are suitable for use as high-energy storage density dielectrics because of their high permittivity. This study investigated the ferroelectricity and energy storage behaviors of PVDF Langmuir–Blodgett (LB) nanofilms at sub-50 nm thicknesses. The ferroelectric hysteresis loops were measured using a Sawyer–Tower circuit in different electric fields. An energy density of 6.0 J/cm3 at 500 MV/m was demonstrated for the 12-nm-thick PVDF LB nanofilm device.

    • Huie Zhu
    • , Tokuji Miyashita
    •  & Masaya Mitsuishi
  • Focus Review |

    Microstructured surfaces have been attracting a considerable amount of attention for many practical applications, such as superhydrophobic materials. In this report, vulcanized rubber was focused on as a flexible and durable hydrophobic material for the fabrication of microstructured superhydrophobic surfaces. Superhydrophobic spike-array microstructures were simply prepared from a vulcanized rubber by using a silicon micromold, and the arrangements were reversibly deformed by repeated stretching without destruction of the spikes. Surface wettability can be controlled by stretching the vulcanized rubber, and the phenomenon was theoretically explained by the wettability transition from a Cassie–Baxter to a Wenzel state.

    • Yuji Hirai
    • , Hiroyuki Mayama
    • , Riku Tamura
    • , Yasutaka Matsuo
    • , Takahiro Okamatsu
    • , Toshihiko Arita
    •  & Masatsugu Shimomura
  • Original Article |

    We developed flame-retardant thermoplastics directly from biomass just by dissolution into ionic liquids and precipitation. During the dissolution, a phosphonate-type ionic liquid adducted on the polymers included in biomass such as cellulose through reaction of the hydroxyl groups. In this method, more than 86% of the hydroxy groups were maintained after ionic liquid substitution because the single phosphonate-type ionic liquid acted as a plasticizer and flame retardant in the plant biomass. Therefore, the plant biomass-derived flame-retardant thermoplastics have the potential for further functionalization.

    • Ryunosuke Nishita
    • , Kosuke Kuroda
    • , Shiori Suzuki
    • , Kazuaki Ninomiya
    •  & Kenji Takahashi
  • Focus Review |

    The nanoscale assembly strategies based on the Langmuir–Blodgett (LB) technique were highlighted to demonstrate the potential for functional device fabrication. (1) The assembly of silsesquioxane-containing polymers can be used to produce uniform monolayers, which are precursors of ultrathin SiO2 films with controlled porosity. (2) The assembly of inorganic nanoparticles and metal-organic framework films on polymer films demonstrates the importance of the spatial alignment of anchoring units. (3) The assembly of π-conjugated units can be used for high-density and low-dimensional assembly.

    • Shunsuke Yamamoto