Water-selective adsorption sites on detonation nanodiamonds
| Autor: | Elda-Zoraida Piña-Salazar, Sakai Toshio, Radovan Kukobat, Katsumi Kaneko, Eiji Ōsawa, Ryusuke Futamura, Takuya Hayashi |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Argon Evolved gas analysis chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Nitrogen 0104 chemical sciences Adsorption chemistry Chemical engineering Selective adsorption General Materials Science Fourier transform infrared spectroscopy 0210 nano-technology Porosity Nanodiamond |
| Zdroj: | Carbon. 139:853-860 |
| ISSN: | 0008-6223 |
| DOI: | 10.1016/j.carbon.2018.07.036 |
| Popis: | Nanodiamond particles form aggregates having porosity in the range of micropores to mesopores with an average pore diameter of 4.5 nm. The measured porosity depends on the removal of pre-occupied water and gases from the nanodiamond aggregates, which is sensitive to thermal treatments. We heated hydrogel nanodiamonds at 423–623 K in vacuo in order to understand the relationship between water adsorptivity and pore structure evaluated from nitrogen and argon adsorption isotherms at 77 K and 87 K, respectively. Temperature-programmed evolved gas analysis showed the evolution of water and CO2 on heating nanodiamonds in vacuo up to 700 K. The surface functional groups of nanodiamonds were not affected by the thermal treatments, as shown by FTIR and XPS analyses. However, the water adsorptivity was enhanced by heating at 623 K due to the removal of the pore blocking effect originated from water molecules selectively adsorbed. Water molecules adsorbed on these selective sites should cause the intensive hygroscopic property of nanodiamonds. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect