井澤 浩則 (イザワ ヒロノリ)

IZAWA Hironori

写真a

所属

工学教育研究部 工学科応用物質化学プログラム担当

職名

教授

研究分野 【 表示 / 非表示

  • ナノテク・材料 / 高分子材料

  • ナノテク・材料 / 生体化学

  • ナノテク・材料 / 機能物性化学

  • ナノテク・材料 / 高分子化学

 

論文 【 表示 / 非表示

  • Preparation of Nanochitin from Crickets and Comparison with That from Crab Shells

    Kishida K., Mizuta T., Izawa H., Ifuku S.

    Journal of Composites Science   6 ( 10 )   2022年10月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Composites Science  

    Crickets are gaining worldwide attention as a nutrient source with a low environmental impact. We considered crickets as a new source of chitin raw material. Chitin isolated from crickets was successfully converted to nanochitin by pulverization. First, chitin was obtained from cricket powder in a 2.6% yield through a series of chemical treatments. Chitin identification was confirmed by FT-IR and 13C NMR. The chitin had an α-type crystal structure and a deacetylation degree of 12%. Next, it was pulverized in a disk mill to obtain nanochitin. Cricket nanochitin was of a whisker shape, with an average fiber width of 10.1 nm. It was larger than that of crab shells, while the hydrodynamic diameter and crystal size were smaller. Such differences in shape affected the physical properties of the dispersion. The transmittance was higher than that of crab nanochitin due to the size effect, and the viscosity was smaller. Moreover, the dry non-woven cricket nanochitin sheets were more densely packed, and their modulus and breaking strength were greater.

    DOI: 10.3390/jcs6100280

    Scopus

  • Drying-Induced Surface Wrinkles Generated on Chitosan Films Having Polyion Complex Skin Layers: Effects of Physical Properties of Skin Layers and Substrates on Surface Wrinkling upon Drying

    Izawa H., Ishisaka S., Saimoto H., Ifuku S.

    Bulletin of the Chemical Society of Japan   95 ( 9 )   1289 - 1295   2022年9月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Bulletin of the Chemical Society of Japan  

    The effects of the physical properties of skin layers and substrates on drying-induced surface wrinkling are investigated with a system using chitosan films having polyion complex (PIC) skin layers. The PIC layers are fabricated with diverse anionic polymers having similar molecular weights on a chitosan (CS) film surface, and the films are dried. In all cases, surface wrinkles form but their sizes vary widely depending on the molecular structure. In particular, wrinkles formed with ligninsulfonate are much larger than those formed with the others. The skin layers differ significantly in surface hardness but not in thickness, indicating that wrinkle sizes induced by PIC skin layers are predominately determined by the hardness of the layers or by physical properties affected by hardness, such as shrinkage volume. The effects of the elastic moduli and shrinkage volume of the substrates are evaluated with higher molecular weight CS and surface-deacetylated chitin nanofiber composite CS films that have different elastic moduli but show very similar swellingdrying behaviors. The wrinkle sizes and skin layer thicknesses also suggest that wrinkle size in this system depends on the hardness of the skin layers or on the physical properties affecting the hardness.

    DOI: 10.1246/bcsj.20220177

    Scopus

  • Optimization of Chitin Nanofiber Preparation by Ball Milling as Filler for Composite Resin

    Zewude D.A., Izawa H., Ifuku S.

    Journal of Composites Science   6 ( 7 )   2022年7月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Composites Science  

    Chitin nanofiber is a nanomaterial produced by pulverizing chitin, the main component of crab shells. Since it has excellent mechanical properties, it is expected to be used as a reinforcing material to strengthen materials. Chitin was mechanically ground in water using a ball mill to prepare nanofibers. The ball size, total ball weight, and milling time were varied, and the resulting water dispersion and the cast film were analyzed to optimize the conditions for efficient preparation. The length and width of the nanofibers were also measured by SEM and AFM observations. The size of the balls affected the level of grinding and the intensity of impact energy on the chitin. The most efficient crushing was achieved when the diameter was 1 mm. The total ball weight directly affects the milling frequency, and milling proceeds as the total weight increases. However, if too many balls occupy the container, the grinding efficiency decreases. Therefore, a total ball weight of 300 g was optimal. Regarding the milling time, the chitin becomes finer depending on the increase of that time. However, after a specific time, the shape did not change much. Therefore, a milling time of approximately 150 min was appropriate.

    DOI: 10.3390/jcs6070197

    Scopus

  • A photo-induced colorimetric reaction of N,N'-bis[2-(trimethylammonium)ethyl]-1,8:4,5-naphthalenetetracarboxdiimide for detection of carboxylate anions

    Izawa H., Yasufuku F., Matsumoto T., Ifuku S., Saimoto H., Sumita M.

    Tetrahedron Letters   100   2022年6月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Tetrahedron Letters  

    Here we show a novel colorimetric sensor system with a photo-induced colorimetric reaction of N,N'-bis[2-(trimethylammonium)ethyl]-1,8:4,5-naphthalenetetracarboxdiimide (TENDI) to detect and quantify carboxylate derivatives. In the presence of CH3COONa, TENDI aqueous solution under UV irradiation shows a photo-induced colorimetric reaction, which is due to the production of naphthalenediimide (NDI)-based radical anions whose absorbance peaks appear at around 400–600 nm. In contrast, no color changes are observed in the cases of diverse inorganic salts. In addition, TENDI shows another ability to discriminate the structural features of carboxylate derivatives by color tone. Moreover, interestingly, the Hill equation can approximate the relationship between carboxylate concentrations and absorbance values on the maximum absorbance wavelengths of the absorbance peaks due to the NDI-radical anions.

    DOI: 10.1016/j.tetlet.2022.153860

    Scopus

  • Disease resistance and growth promotion activities of chitin/cellulose nanofiber from spent mushroom substrate to plant

    Hujun Li, Saori Yoshida, Naofumi Mitani, Mayumi Egusa, Momoko Takagi, Hironori Izawa, Teruyuki Matsumoto, Hironori Kaminaka, Shinsuke Ifuku

    Carbohydrate Polymers   284   119233 - 119233   2022年5月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier BV  

    DOI: 10.1016/j.carbpol.2022.119233

全件表示 >>

科研費(文科省・学振・厚労省)獲得実績 【 表示 / 非表示

  • 微細構造表面を誘起するスキン層の科学の開拓

    研究課題/領域番号:19K05616  2019年04月 - 2022年03月

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    井澤 浩則

     詳細を見る

    担当区分:研究代表者