著者

高井(山下) 千加 馬渕 裕也 池田 純子 藤 正督 仙名 保 大矢 豊

出版者

一般社団法人 粉体工学会

雑誌

粉体工学会誌 (ISSN:03866157)

巻号頁・発行日

vol.58, no.4, pp.164-169, 2021-04-10 (Released:2021-05-21)

参考文献数

16

被引用文献数

1 1

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Mechanochemistry offers sustainable synthesis of the functionalized cellulose nanofiber (CNF). In this study, changes in the microstructure of the CNF aqueous sol by planetary ball milling were investigated in terms of its rheological behavior, crystallinity, and diameter distribution. The surface activity of the CNF was additionally characterized by a pulsed nuclear magnetic resonance (NMR). A decreased thixotropy hysteresis loop observed in the 100 min−1-treated CNFs indicated a weaker interaction among the fibers, but still having a three-dimensional structure. 300 min−1 could collapse them. A decreased x-ray diffraction peak intensity observed in the 500-min−1-treated CNF could indicate a split in the fiber’s bundle as well as shredding. An increase in the wet surface area (SNMR) could indicate surface activity in the 500-min−1 milled CNF sol. Such newly formed hydroxyl groups can serve as effective reaction sites with, for example, the TiO2 precursor and perhaps favorably works to improve the photocatalytic performance.

著者

銭 端芬 大矢 豊 中川 善兵衛 浜野 健也

出版者

社団法人 日本セラミックス協会

雑誌

Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌) (ISSN:09145400)

巻号頁・発行日

vol.103, no.1202, pp.1022-1026, 1995-10-01 (Released:2010-08-06)

参考文献数

20

被引用文献数

3 3

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Aluminum titanate ceramics were fabricated from compacts of aggregated mixture of alumina and titania. The mixture was prepared by precipitation of aluminum hydroxide from aqueous solution of aluminum nitrate, containing rutile powder. After calcination, the mixture was crushed and classified to fractions' 2-5, 5-10, 10-20, 20-47 and 47-77μm sizes. The SEM observation of compacts of the aggregates revealed that the aggregates were not broken by the compaction. The fired bodies of the compacts consisted of oriented aluminum titanate grains. The sizes of the oriented regions were about 4 times larger than the initial aggregate sizes. The reasons for the formation of the oriented grains were considered as follows: the formation of aluminum titanate has low change in free energy, increases elastic energy, and is endothermic. Because of these reasons, grain boundary energy becomes significant in nucleation of aluminum titanate and, therefore, the nucleation occurs epitaxially to result in the oriented texture. The semi-quantitative estimation of change in energies during formation of aluminum titanate agrees with the argument.