الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
”Natural Polymer–Carbon Nanotube Composites Prepared by Gamma Radiation for the Removal of some Radionuclides” Multiwalled carbon nanotubes (MWCNTs) have high Young’s modulus, low density, and excellent electrical and thermal properties, which make them ideal fillers for polymer composites. Homogeneous dispersion of MWCNTs in a polymer matrix plays a crucial role in the preparation of polymer composites based on interfacial interactions between MWCNTs and the polymer matrix. The addition of a small amount of MWCNTs strongly improves the electrical, thermal, mechanical and chemical properties of the composites. The work carried out in the present thesis based on synthesis, structural analysis of natural polymers/multiwalled carbon nanotubes composite for removal of 134, 60Co, and 152+154Eu radionuclides. This thesis comprises three parts in addition to references. Chapter One: Introduction. This chapter includes an introduction about composite, nanocomposite, and nanofiller. In addition, this chapter includes properties, synthesis methods, dispersion methods and application of CNTs, especially in the green nanocomposite. This chapter includes also the modification processes of CNTs by polymer matrix to form nanocomposites. Polymer matrix, grafting copolymerization and template techniques are discussed. This introduction also includes brief accounts on the origin, classification and treatment method of radioactive wastes This chapter includes reviews of natural polymer carbon nanotubes composites like chitosan/CNTs, alginate/CNTs, and starch/CNTs composites.
Summary and Conclusions
164
Chapter Two: Experimental.
This part contains materials (chemicals, equipment and tools, and
radioactive material used in this thesis). Also includes briefly notes about
the methodology used for the synthesis of seven natural
polymer/multiwalled carbon nanotubes composites
In addition, this chapter contains adsorption studies of radioactive isotopes
such as 134Cs, 60Co and 152 + 154Eu
Chapter Three: Results and Discussion.
This chapter contains the experimental results obtained in this work,
divided into four main parts as follow:
The first part focuses on synthesis of
Chitosan-acrylic acid/multiwalled carbon nanotubes,
Chitosan-acrylic acid-1-vinyl-2-pyrrolidone/multiwalled carbon
nanotubes,
Chitosan-1-vinyl-2-pyrrolidone/multiwalled carbon nanotubes,
Alginate acrylic acid/multiwalled carbon nanotubes,
Alginate acrylic acid-vinyl sulfonic acid/multiwalled carbon
nanotubes,
Starch- acrylic acid/multiwalled carbon nanotubes, and
Starch-acrylic acid-vinyl sulfonic acid/multiwalled carbon
nanotubes composites
Using gamma radiation for initiating the grafting of monomers
onto natural polymers in the presence of f-MWCNTs as filler by template
polymerization technique.
The second part focuses on the identification of the prepared
bionanocomposites using FTIR, SEM and TGA measurements.
Summary and Conclusions
165
The third part focuses on the use of the synthesized bionanocomposites
for removal of 134Cs, 60Co and 152 + 154Eu radionuclides from aqueous
solution. The adsorption behaviors of bionanocomposites toward
radionuclides were examined using the batch adsorption experiments as a
function of adsorbent weight, pH, adsorption time, temperature and initial
metal ions concentration.
The fourth part focuses on the study of adsorption isotherm, adsorption
kinetics, and thermodynamics.
The adsorption of Co(II), and Eu(III) onto the surfaces of Alg-AAVSA/
MWCNTs, CS-AA-VP/MWCNTs, and Starch-AA-VSA/MWCNTs
and Cs(I) onto CS-AA-VP/MWCNTs follow Langmuir model better than
Freundlich model. While adsorption of Cs(I) ions onto Alg-AAVSA/
MWCNTs and Starch -AA-VSA/MWCNTs follow Freundlich better
than Langmuir model.
The correlation coefficients (R2) for the linear plots of t/qt vs t in the
pseudo-second-order model are more than 0.99 for all the systems. This
suggests that the rate-limiting step is probably chemical sorption or
chemisorption involving valence forces/bonds through sharing or
exchange of electrons between sorbent and sorbate
The negative value of Δ𝐻o indicated that the adsorption was
exothermic in case of cobalt adsorption while The positive value
of Δ𝐻o indicated that the adsorption was endothermic for
europium and cesium
The value of ΔSo, ΔHo and ΔGo are negative, negative and
negative or positive respectively indicating that the adsorption
of Co(II) ions on the adsorbent surface becomes favorable
(spontaneous) at low temperature
The value of ΔSo, ΔHo and ΔGo are positive, positive and negative
or positive respectively indicating that the adsorption of Cs(I) and
Summary and Conclusions
166
Eu(III) ions on the adsorbent surface becomes favorable
(spontaneous) at high temperature.
The Nanocomposites-radionuclides interactions were disused.
Finally, in this study, novel, biodegradable nanocomposite was
synthesized successfully using gamma radiation for initiating the grafting
of synthetic monomers onto natural polymers by template polymerization
technique. FTIR, SEM, and TGA successfully analyzed the structure of the
bionanocomposites. The adsorption process was highly dependent on
operating factors such as initial solution pH, initial metal concentration,
contact time, particle size and temperature. the adsorption of Co(II), and
Eu(III) onto the surfaces of Alg-AA-VSA/MWCNTs, CS-AAVP/
MWCNTs, and Starch-AA-VSA/MWCNTs and Cs(I) onto CS-AAVP/
MWCNTs follow Langmuir model better than Freundlich model while
adsorption of Cs(I) ions onto Alg-AA-VSA/MWCNTs and Starch -AAVSA/
MWCNTs follow Freundlich better than Langmuir model.. The
process has exothermic nature and more favorable at low temperatures in
case adsorption of 60Co while endothermic nature in case adsorption of
134Cs and 125+154Eu. Adsorption kinetics followed the pseudo-second-order
kinetic model for all system. According to the data, it can be concluded
that prepared bionanocomposites can be used effectively for the removal
of Eu(III), Co(II) and Cs(I) ions from aqueous solution using batch
adsorption method with high capacity.
The prepared nanocomposite can be generated by addition 0.1 N
HCl to extract the adsorbed metal ions. The regeneration process of the
nanocomposites can be carried several times for using the nanocomposites
in radioactive liquid waste treatment