Thermal Diffusivity of Zinc Aluminum – Layered Double Hydroxide Using Photoflash Technique
Thermal diffusivity of zinc aluminum layered double hydroxide (Zn-Al-LDH) was measured by using photoflash technique. It used a simple camera flash and polyvinlidene diflouride (PVDF) film as signal generating source and detector respectively. Three series of sample were prepared at pH 7, 8 and...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2009
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/5712/1/FS_2009_3_abstract.pdf |
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| Summary: | Thermal diffusivity of zinc aluminum layered double hydroxide (Zn-Al-LDH) was
measured by using photoflash technique. It used a simple camera flash and
polyvinlidene diflouride (PVDF) film as signal generating source and detector
respectively.
Three series of sample were prepared at pH 7, 8 and 10 and with molar ratios of Zn to Al
in a range from 2 to 6 (Zn/Al = 2, 3, 4, 5 and 6).
The ZnO peaks appeared in x-ray diffraction pattern for all samples except for samples
prepared at pH 7 with ratio 2 and 3 (Zn/Al = 2 and 3) and sample prepared at pH 8 with
ratio 4. The ZnO peaks observed were between 2 = 30° to 2 = 37°. Thermal diffusivity for all three series samples (pHs 7, 8 and 10) was measured at room
temperature. The thermal diffusivity for all three series of samples was found to increase
for the case of molar ratio 2 to 6.
The thermal diffusivity for Zn-Al-LDH at different ratios of Zn-Al-LDH increased with
increasing ratio of Zn to Al. The increasing of thermal diffusivity is due to increasing of
ZnO. Thermal diffusivity at pH 7, increased from 0.15 10−6m2 / s × to 0.22 10−6m2 / s × .
Thermal diffusivity of sample prepared at pH 8 increased from 0.16 10−6m2 / s × to
0.20 10−6m2 / s × while at pH 10, if increased from 0.20 10−6m2 / s × to 0.25 10−6m2 / s × .
Thermal diffusivity at pH 7 has the lowest value and at pH 10 has the highest value.
The sample prepared at pH 7 with ratio 4 (Zn/Al = 4) was heat-treated at different
temperature from 200°C to 600°C, prior to thermal diffusivity measurement at room
temperature.
In the case of heat treated samples, the thermal diffusivity increased from
0.25 10−6m2 / s × to 0.40 10−6m2 / s × with increasing treatment temperature. |
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