Citation
Shapiei, Ahmad Alfaiz
(2005)
Effects of Various Biomolecules and Ultrasonic Wave on the Physic0 Chemical Properties of Zinc Oxide Synthesized by Hydrolysis Method.
Masters thesis, Universiti Putra Malaysia.
Abstract
In this study, the effect of different biosubstrates on the physicochemical
properties of zinc oxide synthesized by the inorganic-organic agglomeration
was characterized. The resulting materials containing layered ZnO was
synthesized via hydrolysis mechanism between zinc nitrate precursor and the
precipitator, sodium hydroxide at pH 10 in the presence of 0.10 M
biosubstrates stabilized using the conventional thennal aging method. It was
found that a pillared layered structure was formed when L-cystine
biomolecule acting as a molecular propped, causing basal expansion of 10.1
%I, whereas other ZnO-biosubtrates agglomeration did not show any changes
to the typical ZnO phase being observed based on the PXRD spectra
obtained. Thus layered ZnO can be regarded as an inorganic vector or host
structure in directing the physicochemical transition of the layer ZnO-Lcystine
in the agglomeration process whereby a lamellar solid is being
formed. The phase transformation that consists of ZnO-L-cystine agglomerate
was shown to have formed a significant chemical constituent with net Lcystine
composition of 21 % and 37 % ex CHNS and EDX measurement compared to the maximum of 5 % and 2 % obtained from other ZnObiosubstrate
agglomerations.
The intercalated ZnO-L-cystine agglomeration has a higher BET surface area
of around 53 m2/g with wider pore size distribution compared to between 4-
34 m*/g (with sharper pore size distribution pattern) of all other ZnObiosubstrate
agglomeration. The phase transformation of ZnO-fructose
agglomerate however has shown to have a structure directing role in forming
well divided monospherical microcrystallines. Together with other ZnObiosubstrate
agglomeration, it was observed that the degree of structural
regularities based on it's surface morphology is in correlation to the Zn/O
mole ratio obtained from EDX calculation whereby low Zn/O mole ratio was
observed to display better crystallinity or higher order of ZnO-biosubstrate
structural transformation.
Nonetheless, the influence of fructose biomolecule on the structural
transformation was demonstrated further in a molar concentration gradient
study, whereby grain-like surface morphology had nucleated into well
divided monospheres in the crystal growing process as observed by SEM
images from 0.01 M to 0.20 M fructose used. The final agglomerate at the
highest molar concentration used (that yields monospherical morphology)
was found to show a marked increase in net fructose composition at about 16
% from 6 % at it's lowest based on the EDX result. On the contrary, PXRD and
FTIR data regarding the physico-chemical strata of the ZnO phase in the
ZnO-fructose agglomerate remains unchanged.Attemp to seek higher degree of structure-property feature of the ZnOfructose
agglomeration, sonification method was done using the accelerated
aging process to activate the electronic state of the solid solution containing
layer ZnO and fructose biomolecule in a series of ultrasonic exposure time
gradient at 0.20 M fructose where stable micro spherical nucleation was
observed earlier. It was found that the influence of ultrasonic irradiation was
able to further doubles the net composition of fructose present (i.e. to 35 %)
in the ZnO-fructose agglomeration compared to conventional thermal aging
method as mentioned earlier. It was noticed also that an equally good surface
morphology without any deformities was produced only at longer
sonification period i.e. at the 60th minutes. In more, the surface area has also
shown to exhibit an increasing trend from 1 to 4.7 m2/g gaining higher pore
volume or pore size distribution at longer sonification period due to higher
chemical reactivity generated in the solid solution. The BET surface area
however, was only half the surface area generated by the hydrothermally
aged ZnO-fructose agglomeration of 9.4 m2/g. The PXRD and FI'IR data
regarding the physico-chemical characteristic also shows that the ZnO phase
in the ZnO-fructose agglomerate remains unchanged with the use of
ultrasound.
Although no significant structural transformation or changes in the lattice
orientation of the layer ZnO in the solid solution during ZnO-fructose
agglomeration in the conventional or the accelerated synthesis method
described, the effect of fructose on the structure directing role and interdiffusion
capability into the ZnO network is prevalent. It is also important to
note that the increase in the porosity or pore profile of the ZnO-fructose
aggregate due to the ultrasound is an additional aspect to enhance the
structure-property relationship which was observed in this work.
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Additional Metadata
Item Type: |
Thesis
(Masters)
|
Subject: |
Zinc oxide - Biomolecules - Hydrolysis - Case studies |
Subject: |
Zinc oxide - Ultrasonic waves - Hydrolysis - Case studies |
Call Number: |
FS 2005 22 |
Chairman Supervisor: |
Professor Mohd Zobir bin Hussein, PhD |
Depositing User: |
Nur Izyan Mohd Zaki
|
Date Deposited: |
12 May 2010 06:38 |
Last Modified: |
17 Oct 2023 07:58 |
URI: |
http://psasir.upm.edu.my/id/eprint/6229 |
Statistic Details: |
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