ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide
ZnAlNO3LDH was synthesized using the co-precipitation method at pH 7±0.1 and ratio Zn/Al=4. The heat treatment of LDH was studied by X-ray diffraction (XRD) and thermogravimetric analysis (TGA/DTG) to investigate the stability of the LDH structure. The in situ electron spin resonance (ESR) spectra o...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2012
|
| Online Access: | http://psasir.upm.edu.my/id/eprint/25128/1/ESR%20spectra%20and%20thermal%20diffusivity%20of%20Zn-AI%20layered.pdf |
| _version_ | 1825925714614943744 |
|---|---|
| author | Ali Ahmed, Abdullah Ahmed Talib, Zainal Abidin Hussein, Mohd. Zobir |
| author_facet | Ali Ahmed, Abdullah Ahmed Talib, Zainal Abidin Hussein, Mohd. Zobir |
| author_sort | Ali Ahmed, Abdullah Ahmed |
| collection | UPM |
| description | ZnAlNO3LDH was synthesized using the co-precipitation method at pH 7±0.1 and ratio Zn/Al=4. The heat treatment of LDH was studied by X-ray diffraction (XRD) and thermogravimetric analysis (TGA/DTG) to investigate the stability of the LDH structure. The in situ electron spin resonance (ESR) spectra of fresh LDH from room temperature up to 190 °C were obtained, which are due to the presence of nitrate radicals in LDH interlayer. ESR spectra of sintered LDH below 200 °C (ex situ ESR spectra) were investigated, which are also due to the nitrate radicals. However, at 200 °C and above, spectra were due to the oxygen vacancies of ZnO, which was formed during the thermal treatment of LDH. Thermal diffusivity of LDH as a function of in situ temperatures results in a nonlinear relation, which is due to the changing water content of LDH when temperature increases. However, thermal diffusivity of LDH as a function of sintered temperatures showed a linear relation and the slope of these data demonstrated the dependency between thermal diffusivity and water content of LDH below 200 °C. For temperature above 180 °C, the thermal diffusivity behavior was mainly due to the ZnO phase in LDH. |
| first_indexed | 2024-03-06T08:01:55Z |
| format | Article |
| id | upm.eprints-25128 |
| institution | Universiti Putra Malaysia |
| language | English |
| last_indexed | 2024-03-06T08:01:55Z |
| publishDate | 2012 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | upm.eprints-251282016-02-10T07:47:15Z http://psasir.upm.edu.my/id/eprint/25128/ ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide Ali Ahmed, Abdullah Ahmed Talib, Zainal Abidin Hussein, Mohd. Zobir ZnAlNO3LDH was synthesized using the co-precipitation method at pH 7±0.1 and ratio Zn/Al=4. The heat treatment of LDH was studied by X-ray diffraction (XRD) and thermogravimetric analysis (TGA/DTG) to investigate the stability of the LDH structure. The in situ electron spin resonance (ESR) spectra of fresh LDH from room temperature up to 190 °C were obtained, which are due to the presence of nitrate radicals in LDH interlayer. ESR spectra of sintered LDH below 200 °C (ex situ ESR spectra) were investigated, which are also due to the nitrate radicals. However, at 200 °C and above, spectra were due to the oxygen vacancies of ZnO, which was formed during the thermal treatment of LDH. Thermal diffusivity of LDH as a function of in situ temperatures results in a nonlinear relation, which is due to the changing water content of LDH when temperature increases. However, thermal diffusivity of LDH as a function of sintered temperatures showed a linear relation and the slope of these data demonstrated the dependency between thermal diffusivity and water content of LDH below 200 °C. For temperature above 180 °C, the thermal diffusivity behavior was mainly due to the ZnO phase in LDH. Elsevier 2012 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/25128/1/ESR%20spectra%20and%20thermal%20diffusivity%20of%20Zn-AI%20layered.pdf Ali Ahmed, Abdullah Ahmed and Talib, Zainal Abidin and Hussein, Mohd. Zobir (2012) ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide. Journal of Physics and Chemistry of Solids, 73 (1). pp. 124-128. ISSN 0022-3697 http://dx.doi.org/10.1016/j.jpcs.2011.10.016 10.1016/j.jpcs.2011.10.016 |
| spellingShingle | Ali Ahmed, Abdullah Ahmed Talib, Zainal Abidin Hussein, Mohd. Zobir ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide |
| title | ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide |
| title_full | ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide |
| title_fullStr | ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide |
| title_full_unstemmed | ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide |
| title_short | ESR spectra and thermal diffusivity of Zn-Al layered double hydroxide |
| title_sort | esr spectra and thermal diffusivity of zn al layered double hydroxide |
| url | http://psasir.upm.edu.my/id/eprint/25128/1/ESR%20spectra%20and%20thermal%20diffusivity%20of%20Zn-AI%20layered.pdf |
| work_keys_str_mv | AT aliahmedabdullahahmed esrspectraandthermaldiffusivityofznallayereddoublehydroxide AT talibzainalabidin esrspectraandthermaldiffusivityofznallayereddoublehydroxide AT husseinmohdzobir esrspectraandthermaldiffusivityofznallayereddoublehydroxide |