LAGUNA DESIGN

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  • 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
  • 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
  • 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