著者

Chika Takai-Yamashita Emiko Sato Masayoshi Fuji

出版者

Hosokawa Powder Technology Foundation

雑誌

KONA Powder and Particle Journal (ISSN:02884534)

巻号頁・発行日

vol.37, pp.233-243, 2020-01-10 (Released:2020-02-29)

参考文献数

37

被引用文献数

7 15

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The NMR-based solvent relaxation technique, a non-invasive tool to characterize the surface of particles, which are dispersed in a liquid, was applied to characterize the nanoparticles’ aggregation structure. The liquid molecules in a dispersion undergo a rapid exchange between the bound states at the interface and highly mobile free states in a bulk liquid. The relaxation time of the liquid molecules bound on the particle surface is shorter than that of the free states liquid. By detecting how much liquid is bound on the particle surface, the wetted specific surface area (SNMR) can be determined. In this study, it was clarified that the water adsorbed at more than a 1.138 layer from the silica surface can be detected by the NMR and the maximum limitation ranged from 2.160 and 3.336 layers. The model aggregates with an artificial solid neck among the particles were mixed with the silica nanoparticle dispersion. Although the determined SNMR was underestimated compared to SBET from gas adsorption, even a low ratio (5 mass%) of the model aggregates in the dispersion can be detected.