| dc.description.abstract | Silicon carbide (SiC) is well known as one of the most useful materials due to its high
hardness next to diamond. Silicon carbide nanotubes (SiCNTs) and nanowires (SiCNWs)
especially have high potential in high temperature and harsh environment electronic
applications. The objectives of this study were to investigate the effect of ratio of SiO2
particles and MWCNTs, heating temperature, heating duration and types of CNTs
(MWCNTs and SWCNTs) on the synthesis of SiCNTs by microwave heating in terms of
morphology, compositions, optical properties and thermal stability. Effect of different ratio
was studied by varying the molar ratio of SiO2 particles and MWCNTs in the blend to 1:1,
1:3, 1:5 and 1:7 while for the study of effect of heating temperature, temperature was varied
from 1350 °C, 1400 °C and 1450 °C. Heating duration of 20, 40 and 60 minutes were used
in this study to investigate the effect of heating duration on the synthesis of SiCNTs. Two
types of CNTs (MWCNTs and SWCNTs) were used to investigate the effect of type of
CNTs on synthesized SiCNMs. Ultrasonic mixing was used to mix SiO2 particles and
MWCNTs in ethanol which was then dried before being cold pressed into 3 mm pellet.
After that, the pellet was put into alumina crucible and microwave heating was conducted
in a 2.45 GHz multi-mode cavity microwave with heating rate of 30 °C/minute. FESEM
and TEM were used to investigate the morphology of the SiCNMs. Meanwhile,
composition analysis was done by using XRD and EDX. PL was used to study the optical
properties, while thermal properties were investigated by using TGA analysis. Ratio 1:3 of
SiO2 particles and MWCNTs has showed synthesis of single-phase SiCNTs as supported
by XRD patterns where no residual of SiO2 particles and MWCNTs was observed.
Meanwhile, heating temperature at 1400 °C and 40 minutes heating duration was
determined as the most ideal temperature to synthesize single-phase SiCNTs in which SiO2
particles and MWCNTs reacted completely become single-phase SiCNTs. Furthermore,
single phase SiCNTs was successfully synthesized from blend of SiO2 particles and
MWCNTs in the ratio of 1:3 while blend of SiO2 particles and SWCNTs in similar ratio
formed SiCNWs. Images of TEM have confirmed that the synthesized SiCNTs has hollow
tubular structure while SiCNWs has a solid nanowires structure. It can be postulated that
ratio of SiO2 particles and MWCNTs, heating temperature and heating duration has
significant effect to the synthesis of SiCNTs. Besides that, type of CNTs (MWCNTs and
SWCNTs has significant effect on the formation of SiCNMs where SiCNTs was obtained
from the blend of SiO2 particles and MWCNTs while SiCNWs synthesized when blend of
SiO2 particles and SWCNTs was used. It can be concluded that microwave heating for the
synthesis of single-phase SiCNTs was achieved when blend of SiO2 particles and
MWCNTs in the ratio of 1:3, heating temperature at 1400 °C, heating duration of 40
minutes was used in this study. | en_US |
