الفهرس 
Chapter (1): Theoretical Background and Literature SurveyOnly 14 pages are availabe for public view
 |  | from | 136 |  |  |
| | | from | 136 | | |
Abstract
Hydrolysis of titanium(iv) isopropoxide produced nanoparticles
(NPs) of amorphous and anatase titanium dioxide (TiO2), known as AT and
CT. Using X-ray diffraction (XRD) and a field emission scanning electron
microscope (FE-SEM), the microstructure and morphology of the
generated TiO2 NPs were examined. The observed pattern of AT has a
distinct step-hump characteristic, which is indicative of an amorphous
structure. Conversely, the pattern obtained for CT suggests the presence of
TiO2 anatase production. Two nanocomposite (NC) systems were
fabricated by adding AT or CT NPs to paraffin wax (PW) at 0% to 0.5%.
The FE-SEM micrographs showed a good distribution of NPs in PW/TiO2
NCs. The melting point (Tm), latent heat of fusion (LH), and latent heat
rate (SP) of NCs were studied using non-isothermal differential scanning
calorimetry (DSC). PW/TiO2 NC samples had 19.1% and 298.6% higher
LH and SP values than pure PW samples, and 21.2% and 134.3% higher
LH and SP values. Thermal gravimetric analysis (TGA) investigated the
thermal stability of the PW/CT NCs under examination. Thermal stability
improved up to 0.25 wt.%, then deterioration accelerated. The Coats-
Redfern method was used to determine the degradation activation energy
(Ea) in PW/CT NCs. The NC sample with 0.15T wt.% CT NPs had an Ea
of 78.09 KJmol-1, up from 66.19 KJmol-1 for pure PW. The basic fluid was
Ethylene Glycol (EG) for two nanofluid systems. The nanofluids were
changed by adding AT or CT NPs at 0, 0.2, 0.5, 0.7, and 1 wt.%. The hotwire
method was used to measure these nanofluids’ thermal conductivity
(k). The study found that NF samples with 0.5 wt.% AT NPs and 0.7 wt.%
CT NPs had 102.3% and 144.4% higher k values than pure EG samples.