Online ISSN : 2436-7338
Print ISSN : 0289-7709
Volume 41, Issue 5
Displaying 1-2 of 2 articles from this issue
  • Takefumi NARITA, Juna KOIZUMI, Kasumi WADA, Ryo NAKADA, Ikuhiro TANIDA ...
    2023 Volume 41 Issue 5 Pages 31-38
    Published: October 25, 2023
    Released on J-STAGE: February 29, 2024

    In this study, paramylon nanofiber suspensions (PNFSs) with different dispersibility were developed by adjusting the pretreatment conditions, including pretreatment time and concentration of paramylon granules. The rheological, tribological, and chemical properties of the resulting PNFSs were evaluated. Two types of paramylon nanofiber (PNF) were prepared through water-jet (WJ) defibrillation: PNF-MP1, which underwent a short pretreatment time and low concentration and PNF-MP2, which underwent a long pretreatment time and high concentration. The defibrillation treatment partially converted PNF-MP1 to fibers, with some granules remaining. In contrast, PNF-MP2 obtained excellent nanofiber formation owing to the accelerated defibrillation effect. The rheological evaluation revealed that PNF-MP2 exhibited the highest dispersibility and the reversibility of viscosity recovery. Friction property evaluation showed that PNF-MP2 displayed excellent lubrication effects. Wide angle X-ray diffraction (WAXD) analysis showed that the defibrillation treatment impaired the microcrystallization and crystal regularity of PNF. X-ray photoelectron spectroscopy (XPS) surface elemental analysis showed that the defibrillation treatment exposed hydroxyl groups on the PNF surface, enhancing its hydrophilicity.

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