The translational, rotational, and phonon dynamics of water in ZrO2 /water nanofluid

• Published in: Journal of molecular liquids 2022-11, Vol.366, p.120218, Article 120218
• Main Authors: Yoshida, Koji, Sanada, Yusuke, Yamaguchi, Toshio, Matsuura, Masato, Tamatsukuri, Hiromu, Uchiyama, Hiroshi
• Format: Article
• Language: English
• Subjects: Inelastic X-scattering; Nanofluid; Quasi-elastic neutron scattering; Water dynamics; Zirconium oxide
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2022.120218

[Display omitted] •The water dynamics in zirconium oxide nanofluid were investigated by QENS, 17O NMR relaxation, and IXS.•The translational and rotational motions of water molecules become retarded with increasing the concentration of ZrO2.•The high-frequency sound velocity of the nanofluid is slightly larger than that of pure water.•There is an attractive interaction between water molecules and the surface of the nanoparticles. The translational, rotational, and phonon dynamics of water in zirconium oxide (ZrO2) nanofluid were investigated by quasi-elastic neutron scattering, 17O NMR relaxation, and inelastic X-ray scattering, respectively. The particle size of ZrO2 is 3～100 nm, and the concentration of ZrO2 nanoparticles is 5, 10, 20, and 30 wt%. The translational and rotational motions of water molecules become retarded with increasing the concentration of ZrO2. This indicates that there is an attractive interaction between water molecules and the surface of the nanoparticles. The high-frequency sound velocity of the nanofluid obtained from phonon dynamics measurements is slightly larger than that of pure water although it is not much difference compared to the case of the translation and rotation. These findings indicate that water dynamics in the nanofluid is different from that of the bulk. It might be reasons for the enhancement of the thermal conductivity of the nanofluid.