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Giant Permittivity of Confined Water on Nanodiamondsстатья
Дата последнего поиска статьи во внешних источниках: 20 апреля 2022 г.
- Авторы: Batsanov Stepan S., Gavrilkin Sergey M., Korzhenevskiy Alexander P., Antipenko Alexander G., Shatalova Tatyana B., Batsanov Andrei S.
- Журнал: Journal of Physical Chemistry C
- Том: 126
- Номер: 14
- Год издания: 2022
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 6385
- Последняя страница: 6393
- DOI: 10.1021/acs.jpcc.1c08827
- Аннотация: The Dielectric permittivity (ε) of hydrated detonation nanodiamonds (HDNDs) with variable water content (W) was measured at 1 kHz to 1 MHz frequencies, using a capacitor cell with bare or blocked electrodes. At low frequencies, HDNDs show a giant ε of 104 to 106, i.e., 105 to 107, for the confined water (CW) itself, probably due to microcapacitors formed at particle surfaces. At higher frequency, ε decreases but even at 1 MHz is up to 103 for hydrates and 104 for CW (cf. 78 for bulk water), probably due to disruption of hydrogen bonds. ε as a function of W peaks at W = 6 to 16% and declines on further hydration, while the conductivity continued to increase. CW density, measured by pycnometry, near the surface is ca. 1.5 g/cm3 for nanodiamonds with low hydrogen content but ca. 0.5 g/cm3 for other types, in each case converging to 1 g/cm3 in further layers. Evolved gas analysis of HDND reveals two types of adsorbed water with distinct peaks at 150–180 and 230–300 °C. In view of these and earlier results, the decreased ε of CW determined by atomic force microscopy must be taken with caution.
- Добавил в систему: Шаталова Татьяна Борисовна